Download Oats for Health Booklet

oats
for HEALTH:
A research summary for health professionals
edited by Elisabeth
Weichselbaum PhD, MSc, NZ Registered Nutritionist 2014
authors
Dr Elisabeth Weichselbaum
Dr Michelle Broom
OATS WITH MILK
Page 8
Grains & Legumes Nutrition
Council, Australia
PhD, MSc, NZ Registered
Nutritionist
APD, Nutrition Program
Manager
Dr Peter Clifton
Professor of Nutrition
University of South Australia,
Adelaide, South Australia
UNPACKING THE OAT GRAIN
Page 12
OATS CONSUMPTION &
GLUCOSE CONTROL
Page 25
Dr Alastair Ross
Prof. Mohsen Meydani
Dr Kristina Andersson
Dr Luud JWJ Gilissen
Assistant Professor in
Food & Nutritional Science
Director, Vascular Biology
Laboratory
Professor of Nutrition, Senior
Scientist
PhD Researcher
Coordinator
Allergy Research
JM USDA-Human Nutr. Res.
Ctr. on Aging, Tufts University,
Boston
Dept. Experimental Medical
Science, Lund University,
Sweden
ANTI-INFLAMMATORY
PROPERTIES OF OATS
Page 22
OATS & VASCULAR HEALTH
Page 35
Chalmers University of
Technology, Gothenburg,
Sweden
OATS & CHOLESTEROL
LOWERING
Page 30
Dr Per Hellstrand
MD, PhD, Professor
Dr Ingrid M van der Meer
Group Leader Applied
Genomics & Proteomics
Diana M Londono
PhD Student
Dr Marinus JM Smulders
Business Unit Manager
Plant Breeding
Plant Research International –
Wageningen UR,
The Netherlands
OATS & ALLERGY/
INTOLERANCE
Page 18
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oats for health
3
contents
KEY TAKE OUTS........................................................................................................... 6
KEY NUTRITION FACTS............................................................................................... 7
OATS WITH MILK......................................................................................................... 8
A HEALTHY BREAKFAST.............................................................................................. 8
DIFFERENT TYPES OF OATS........................................................................................11
UNPACKING THE OAT GRAIN................................................................................... 12
OATS: A UNIQUE PACKAGE OF NUTRIENTS............................................................ 14
OATS & ALLERGY/INTOLERANCE............................................................................. 18
ANTI-INFLAMMATORY PROPERTIES OF OATS........................................................ 22
OATS CONSUMPTION & GLUCOSE CONTROL...................................................... 25
OATS & CHOLESTEROL LOWERING......................................................................... 30
OATS & VASCULAR HEALTH..................................................................................... 35
REFERENCES.............................................................................................................. 38
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oats for health
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KEY TAKE OUTS
OATS ARE:
LOW IN SODIUM
Oats are one of the few breakfast cereal
options with no added salt and are
therefore low in sodium
HELP REDUCE BLOOD
PRESSURE
Oats may help reduce
blood pressure in
humans, and there have
been indications of a
greater effect in obese
than in lean persons
UNIQUE
ANTIOXIDANTS
Oats are the only grain to provide
an antioxidant-like substance
known as avenanthramides
HELP REDUCE HEART
DISEASE RISK
Avenanthramides have antioxidant,
anti-inflammatory and antihistamine
properties and may reduce the
risk of heart disease and several
other diseases associated
with inflammation
RICH IN -GLUCAN
Oats are unique in that they are one of the
richest sources of -glucan soluble fibres
(together with barley, rye and fungus)
HELP LOWER BLOOD CHOLESTEROL
-glucan in oats is proven to help lower blood
cholesterol levels and, as a viscous fibre,
lowers the glycaemic response to a food
SOURCE OF
WHOLE GRAINS,
VITAMINS & MINERALS
Typically eaten as whole grains, oats provide
dietary fibre, a range of essential vitamins and
minerals, and over 26 bioactive substances
(Themselves) ARE GLUTEN-FREE
Oats themselves are gluten-free, but as they are a between season crop and may
become contaminated with wheat either in the field or across the supply-chain, they
cannot be labelled as such in Australia or NZ. A small number of Coeliac sufferers
may also react to a type of protein naturally found in oats (avenins), but for most
Coeliac sufferers, uncontaminated oats (where available) are safe to eat.
key nutrition facts on oats:
Oats have the capacity to help
maintain endothelial function
Oats are typically eaten as the whole grain, providing the whole package of fibre, nutrients and
other bioactive compounds.
Fibre
Oats provide fibres that are important for gut regularity, and fibre that helps manage cholesterol levels.
High in β- glucan
-glucan is a type of fibre that helps with glycaemic control and lower blood cholesterol levels.
Source of thiamin, iron, magnesium & phosphorous
Vitamins and minerals provided by oats are important for good health. Combining oats with milk provides
a whole package of essential nutrients.
6
Whole grains
A natural source of energy
Oats provide energy in the form of starchy carbohydrates. These provide fuel for the brain (glucose),
helping with mental performance throughout the morning.
HELP MAINTAIN
ENDOTHELIAL
FUNCTION
Low in sodium
Oats are naturally low in sodium
oats for health
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Oats with milk
A nutritious start to the day!
Dr Elisabeth Weichselbaum, Independent Nutrition Scientist and Consultant
Not only does breakfast provide us with the energy we need, eating breakfast has also been associated with improved cognitive
performance throughout the morning (Hoyland et al. 2009), a lower likelihood of being obese (Szajewska & Ruszczynski 2010), and
with better nutrient intakes (Grieger & Cobiac 2012; Fayet-Moore et al. 2012; Gibson & Gunn 2011; Williams 2007) compared with
breakfast skipping. Because it is such an important meal of the day, it is best to choose a breakfast that provides a good balance of
important nutrients, without providing too much sodium, fat or sugar. Having oats with milk or yoghurt is a great option for breakfast.
Adding a handful of chopped fruits ensures you are getting several major Core Food Groups in one meal.
Australian Guide to Healthy Eating
Australian Guide to Healthy Eating
A healthy breakfast provides....
Enjoy a wide variety of nutritious foods
from these five food groups every day.
Drink plenty of water.
Enjoy a wide variety of nutritious foods
from these five food groups every day.
Grain (cereal) foods,
Drink plenty of water.
mostly wholegrain
and/or high cereal
fibre varieties
Oats provide starchy carbohydrates,
which provide the fuel not only for
muscles and organs, but provide the
sole fuel (glucose) for the brain.
Vegetables and
legumes/beans
Muesli
Grain (cereal) foods,
Polenta
mostly wholegrain
and/or high cereal
fibreQuinoa
varieties
Muesli
Polenta
Fettuccine
Penne
As oats are eaten as a whole
grain, they provide good amounts
of dietary fibre. One type of fibre
that is present in good amounts
in oats (and barley), but not in
some other cereals, is -glucan,
a soluble fibre that helps lower
the glycaemic response and
reduce blood cholesterol levels.
4. A drink
for hydration
Red kidney
beans
Quinoa
Fettuccine
Penne
Wheat flakes
Red lentils
Red kidney
Chickpeas
beans
Wheat flakes
Red lentils
Chickpeas
Red kidney
beans
3. A serve of fruit
or vegetable
Lentils
Mixed nuts
Chickpeas
Red kidney
beans
Lentils
Mixed nuts
Chickpeas
Fruit
OATS
thiamine
iron
magnesium
fibre
Lean meats and
poultry, fish, eggs,
tofu, nuts and seeds
and legumes/beans
MILK
Lean meats and
poultry, fish, eggs,
tofu, nuts and seeds
and legumes/beans
Use small amounts
calcium
riboflavin Use small amounts
vitamin B12
Fruit
Milk, yoghurt, cheese and/or
alternatives, mostly reduced fat
Only sometimes and in small
amounts
Milk,
yoghurt, cheese and/or
2. Dairy for protein
A bowl of oats and
milk is a good source of
protein, is high in whole grains
and fibre, rich in β -glucan (proven
to help lower cholesterol), is a low
GL meal and low in sodium –
overall, a healthy start
to the day!
OATS FOR BETTER HEALTH
As well as providing valuable nutrients, oats have been
suggested to benefit health in other ways. These benefits will
be discussed in more detail in this brochure – written by various
experts working and researching in the respective areas.
The different sections discuss what components of oats provide
benefits, and how they do so.
FIGURE 1: Contribution of 40g oats with 125mL reduced
fat milk to an adult’s daily nutrient requirements
%of Recommended Daily Intake
THIAMINE
4
RIBOFLAVIN
14
NIACIN
1 4
FOLATE
3 4
VITAMIN B6
3 2
VITAMIN B12
38
CALCIUM
19
ZINC
22%
18
18%
4
5%
7%
5%
38%
2
10%
3 7
IODINE
12
12%
IRON
13
13%
MAGNESIUM
5
PHOSPHORUS
13
FIBRE
13
PROTEIN
9
21%
21%
16
29%
16
13%
9
18%
alternatives, mostly reduced fat
Only sometimes and in small amounts
Source: Australian Government (www.eatforhealth.gov.au)
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Oats with milk is not only a delicious breakfast option, but also
provides a whole package of important nutrients, making it
a nutritious start to the day (see section ‘Unpacking the oat
grain’). Oats with milk are also a low sodium breakfast with
less than 0.1g. This is because rolled oats have no added salt,
unlike bread and various types of other breakfast cereals on
the market.
Oats also provide more protein than other cereal grains –
as well as being important for growth and tissue repair, protein
helps increase satiety. A 40g portion of rolled oats together
with 125mL (½ cup) milk provide almost 20% of the daily
protein requirements.
Vegetables and
legumes/beans
1. Cereals for fibre & whole grain
Combining oats with milk
makes a breakfast combo
packed with nutrients
Reduced Fat Milk (1%)
Oats, rolled, 40g
The clear conclusion is still that oats can help lower cholesterol
and should be an important component of heart healthy diets.
oats for health
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Oat Groats
The whole oat as it is harvested from the grain but “de-hulled” so that the inedible
husk has been removed and the oat has been cleaned, making it safe to eat.
These oats can take up to an hour to cook.
Steel Cut Oats/Oat Kibble/
Irish Oatmeal
Oat groats cut into 2-3 pieces with a steel blade
(before being rolled). Cutting the oat exposes more
surface area which can be penetrated by water during
cooking, making it quicker to prepare than an oat groat
(around 30 minutes).
Different
types of oats
Scottish Oats
The Scots traditionally stone
ground their groats and then
rolled them rather than rolling
out steel cut oats. The result are
rolled oats that naturally vary
in size and can help deliver a
creamy textured oatmeal.
Muesli Oats
Muesli oats are rolled to a
greater thickness than other
rolled porridge-type oats. As
with other rolled oats, the oats
are often kilned to give them a
“nutty” taste and help prevent
rancidity and then steamed and
rolled to the desired thickness.
Traditional/Rolled Oats/Oatmeal
As with muesli oats, these are steel cut oats which are
then kilned, steamed and rolled to a specific thickness.
They generally take around 2-5 minutes to prepare.
Quick Oats
Quick oats are the same as other rolled oats, taking the steel cut oat groats and then
kilning, steaming and rolling the oat. They are simply rolled thinner to allow the oat to
cook more quickly; around 90 seconds to prepare in the microwave.
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oats for health
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UNPACKING THE OAT GRAIN
Michelle Broom, APD, Nutrition Program Manager, Grains & Legumes Nutrition Council
It is believed oats have been grown as a food crop since 1000BC (Kent & Evers
1994). Today, oats are the fourth largest grain crop in Australia with more than
1 million tonnes grown every year (Primary Industries Standing Committee 2011).
Oats are predominantly grown in the moist, temperate regions of the southern
states of Australia with significant winter rainfall.
Australia is a major producer of oats globally, as the
fourth largest producer of oats (see Figure 2).
Oats are more frost and waterlog resistant than wheat and barley (AEGIC 2012). However, like all other grains,
drought can affect yield. Although drought affects groat size, drought or excess rain do not have a significant impact
on the nutritional qualities of oats.
In Australia, oats are usually planted in May and harvested in November. The hot, dry
weather in November enhances the storage capacity of the oats (AEGIC 2012).
Most oats grown in Australia are used as stock feed, with only 40% grown as
higher quality milling oats used to feed humans and racehorses
(Index Mundi 2013 and Australian Bureau of Statistics 2012).
FIGURE 2: Main producers of oats worldwide
EU (27 countries)
8.44
Russian Federation
Approximately 20% of Australia’s milling oats are
exported, primarily to Mexico, China and Japan
(AEGIC 2012).
5
Canada
3.25
Australia
FIGURE 3: Areas of oat production.
1.2
0.96
United States
Chile
0.6
China
0.58
Belarus
0.45
Ukraine
0.45
Argentina
Source: AEGIC 2012
0.4
0
1
2
3
4
5
6
7
8
9
OAT PRODUCTION (MILLION TONNES PER YEAR)
Source: Index Mundi, 2013
INCREASING PRODUCTION
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Oats: a unique package of nutrients
Oats are a cereal grain which means they are the seed of
the grass family of plants belonging to the botanical
family Poaceae, or Germinae. Unlike wheat and rye, oats
grow with a husk covering the seed.
This husk is not digestible by humans so must be removed from oats before they can be
used as food. The husk is removed and then the remaining seed, called the oat ‘groat’, is
dried in a kiln so the grain can be stored without spoiling. This kiln drying gives oats their
characteristic ‘nutty’ flavour. Oat husks are sometimes added back into porridge oats as
an additional source of fibre or may be re-used as a source of fibre in animal feeds.
The oat groats are then steamed to stop the enzymes from breaking down the naturally
occurring fats and reduce rancidity. The steamed oats are rolled to form the traditional
rolled oats available in the supermarket.
To make quick cooking oats, or instant oats, the oat groat is cut before being rolled.
The smaller pieces of oat cook more rapidly but still contain all the nutrients of the
whole grain.
Traditional and instant oats are whole grain. They contain all the parts of the original
‘groat’ including the germ (the embryo of the new plant), the endosperm which supplies
energy and nutrients for the growing seed and the outer protective fibre-rich bran layer
(Figure 4). Like in other whole grains, the bran and germ of oats are rich in fibre, vitamins
and minerals and phytonutrients (Fardet 2010).
FIGURE 4: Whole grain structure showing
location of key nutrients
Bran
The outer layer of the
grain which includes the
aleurone layer
• Fibre
• Protein
• B Vitamins
• Trace Minerals
• Phytochemicals
• Enzymes
Endosperm
Provides nourishment
to the germ
•Carbohydrate
• Protein
• Some B Vitamins
•Oil
Germ
Husk (or hull)
Embryo from which the
seedling develops
T he outer protective
shell of the grain
• B Vitamins
• Vitamin E
• Trace Minerals
• Phytochemicals
• Antioxidants
• Unsaturated fats
Whole grains such as oats
contain dietary fibre, a range
of essential nutrients and over
26 bioactive substances such
as phenolic compounds and
plant sterols (Fardet 2010).
It is the whole package of
fibre, nutrients and bioactives
acting synergistically that
are thought to help protect
against chronic diseases like
heart disease, diabetes and
cancer (Fardet 2010).
At only 58% carbohydrate, oats are lower in carbohydrate than other grains.
A 40g serve of raw oats contains 23g of carbohydrate (Grains & Legumes
Nutrition Council 2013). Oats tend to have a slightly higher protein content than
most other cereals at approximately 12% and a higher fat content
(mainly poly- and monounsaturated) (Grains & Legumes Nutrition Council 2013).
It is worth noting that Food Standards Code for Australia and New Zealand
(Standard 1.2.8) specifically prohibits the use of gluten free claims on oat
products due to the likelihood of cross-contamination with wheat, barley or rye
(Food Standards Australia New Zealand 2013). However, efforts to produce
uncontaminated oats have led to more and more uncontaminated products
being available on the market internationally (see section ‘Oats and allergy/
intolerance’ for more details).
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oats for health
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Oats: a unique package of nutrients continued...
Like other whole grains, the bran layer of oats is rich in vitamins and minerals.
It contains a range of nutrients essential for maintaining health including B-group
vitamins, and minerals such as iron, zinc, magnesium and phosphorus (Table 1).
TABLE 1: Nutrient content of rolled oats per 40g serve
Amount per 40g
of oats
% Daily Intake*
(per serving)
Energy
631kJ
7%
Carbohydrate
23.2g
7%
Protein
4.4g
9%
Fat
3.5g
5%
Saturated
0.7g
3%
Polyunsaturated fat
1.2g
n/a
Monounsaturated fat
1.4g
n/a
Fibre
3.8g
13%
Insoluble Fibre**
1.9g
n/a
Soluble Fibre**
1.9g
n/a
ß-glucan**
1.4g
n/a
Thiamin (Vitamin B1)
0.2mg
18%
Riboflavin (Vitamin B2)
0.06mg
4%
Niacin
0.4mg
4%
Folate
7.2µg
4%
Vitamin E
0.1mg
1%
Nutrient
Permitted nutrition
content claim**
Oats also contain both insoluble and soluble fibre
(see Table 2). They have lower levels of insoluble fibre than
other grains such as wheat and rye, but more than other
grains such as rice, millet and corn. However oats are higher
in soluble fibre than most other grains, most notably -glucan
which is proven to help lower blood cholesterol levels and
glycaemic response. Oats are one of the richest cereal sources
of -glucan containing 3.4g per 100g or around 1.4g
per 40g serve.
The ability of whole grains such as oats to increase the
total antioxidant capacity in the plasma is thought to be
predominantly due to phenolic compounds, such as ferrulic
and caffeic acids. Up to 30% of the total phenolic content of
oats is as ‘free phenolics’, which are not bound to fibre or other
compounds. Oats contain up to ten-fold higher levels of free
phenolics than other grains and so have greater potential to
increase antioxidant potential and reduce oxidative stress than
other types of grain (Belobrajdic & Bird 2013).
A serve of goodness....
a 40g serve of rolled oats contains:
Content of free phenolic acids in different types of cereal
Source
Note: good source of fibre under
previous and transitional regulations
629kJ (150 calories)
Source: Belobrajdic & Bird 2013
23g carbohydrate
Barley
5-23µg/g
Wheat
5-39µg/g
4.4g protein
Oat
Rye
3g saturated fat
5-110µg/g
10-35µg/g
4g fibre
Source
TABLE 2: Dietary fibre content of different
types of cereal per 100g
Iron
1.5g
13%
Zinc
0.8mg
7%
Magnesium
52mg
16%
Source
Phosphorus
164mg
16%
Source
Potassium
125mg
n/a
Calcium
18mg
2%
Sodium
2.8mg
0%
Source
Oats
Whole
wheat
Brown
rice
Pearled
barley
9.5
11.3
3.2
11.7
Insoluble fibre (g)
6
10.6
1.6
5.2
Soluble fibre (g)
5
1.6
<0.1
5.4
3.4
0.7
0.1
4.4
Nutrient
Low salt or sodium
Total dietary fibre (g)
ß-glucan (g)
Source: Food Standards Australia and New Zealand 2010; http://www.foodstandards.gov.au/science/monitoringnutrients/nutrientables/Pages/default.aspx
* %Daily intake and permitted nutrition claims are based on Standards 1.1.1, 1.2.7, and 1.2.8 of the Food Standards Australia New Zealand.
**Grains & Legumes Nutrition Council (2013; unpublished). Single sample analysis. Information is true and accurate at time of publication and supplied for
educational purposes only. Grains & Legumes Nutrition Council takes no responsibility for any other use of this data.
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Oats have a higher fat content than other grains as
predominantly polyunsaturated and monounsaturated
fats present not only in the oat germ but especially in the
endosperm. Of the total fat content of oats, 43% is oleic
acid and 35% in linoleic acid (Kent & Evers 1994).
The bran and germ of oats also contain phytochemicals
including tocopherols, tocotrienols, phenolic compounds and
plant sterols, thought to have a beneficial effect on health.
More recent research indicates oats contain avenanthramides,
a unique bioactive substance that has been shown to help
protect blood vessels from the damaging effects of
LDL-cholesterol (Meydani 2009; see section
‘Anti-inflammatory properties of oats’ Page 20).
Source: Food Standards Australia and New Zealand 2010 and courtesy of
Grains & Legumes Nutrition Council, various sources.
http://www.foodstandards.gov.au/science/monitoringnutrients/nutrientables/Pages/default.aspx
oats for health
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Oats & ALLERGY/INTOLERANCE
Dr Luud JWJ Gilissen, Dr Ingrid M van der Meer, Diana M Londono, Dr Marinus JM Smulders
Plant Research International – Wageningen UR, The Netherlands
food allergy & intolerance definitions
Allergy
•An excessive reaction of the immune system to a
normally harmless compound, usually a protein
(which becomes an ‘allergen’)
•Allergies are immunoglogulin E (IgE)-mediated,
and are immediate and often severe
•Allergic reactions can occur in any body surface
including skin, lungs and intestine in contact with
the environment
Intolerance
•Detrimental physiological or (auto-)immune reaction
•Often delayed or chronic reaction
•Gluten intolerance (coeliac disease) is an auto-immune
disease leading to a wide spectrum of symptoms
(e.g. chronic bowel complaints, growth retardation,
chronic fatigue)
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Proteins with little potential to
trigger intolerances
Oats – a cereal suitable for most
coeliac sufferers
Oats, as other cereals (rice, wheat, barley, rye, maize,
sorghum and various species of millet), contain various
types of proteins, including water-soluble albumins,
saline-soluble globulins, ethanol-soluble prolamins,
and ethanol- plus reducing agent-soluble glutenins.
The absolute and relative amounts of these protein types
vary considerably among cereals.
Coeliac disease (CD) is a common food intolerance
to gluten proteins of wheat, barley and rye, with a
prevalence of 0.5-2% among the Western population.
Most patients with CD can consume oats without
detrimental inflammation of the small intestine.
For example, wheat grains contain mostly
(80% of the total protein content) prolamins
and glutenins, which are highly diverse in
composition, poorly degradable by humans,
and remain immunogenic in the intestine
(i.e. they can still trigger allergic and intolerance
reactions). In contrast, oat grains contain
mostly (80% of the protein fraction) easilydegradable globulins. The prolamin plus
glutenin content (glutenin makes up a very
minor portion) of oats is generally below 10%
(Webster & Wood 2011) and the molecular variation
among and immunogenicity of these proteins is limited,
which means they are unlikely to trigger intolerances
(Londono et al., 2013). The prolamins in oat are
called ‘avenins’.
Allergies to oats are rare
Although allergy to cereals is rare, representative
proteins of all the above-mentioned solubility groups
are known as potential food allergens in several cereal
species. In patients with food allergy-related atopic
dermatitis, strong IgE cross-reactivity of several proteins
of different molecular weight was seen between
wheat, barley and rye, reflecting their close taxonomic
relationship (Varjonen et al., 1994). This means that a
person who is allergic to proteins present in wheat may
also experience allergic reactions to similar proteins
present in barley or rye. In terms of cereal food allergy,
the most commonly mentioned crops triggering reactions
are wheat, maize and rice. In contrast, oat food allergy
is only known as an exceptional, delayed-type,
cell-mediated allergy, limited to infancy and usually
resolving later in life (Sicherer & Sampson 2010).
The majority of adults and children with CD appear to tolerate
moderate amounts (20 g/day for children to 70 g/day for
adults) of pure oats (Pulido et al. 2009). The biggest problem
with oats for CD patients is the fact that commercial oat
products can become contaminated with wheat (Gelinas et
al. 2008). Contamination can already occur in the field when
wheat, barley or rye plants grow among oat plants and are
not removed systematically, but contamination can also occur
later in the food production chain, during harvest, transport,
storage and further processing. The level of contamination is
almost always sufficient to cause symptoms in CD sufferers.
Consequently, a guaranteed gluten-free oat production chain
is an essential requirement for the production of oat suitable for
the gluten-free market.
Uncontaminated gluten-free oat products are also available
on the Australian market but under the Food Standards code
(Standard 1.2.8) in Australia and NZ, oats are prohibited
from claiming to be gluten free due to the presence of small
amounts of prolamins (i.c. avenins). However, such prolamin
type of proteins are also present in known-as-safe grains like
maize (zeins)and rice (orizalin) (Gilissen et al. 2008). Most
CD sufferers are sensitive to gluten proteins, and only few cases
of oat avenin-sensitive CD patients have been described. The
response in these rare cases has been attributed to two specific
avenin-derived peptides that are different from all known T-cell
epitopes (immunogenic protein fragments) of wheat, barley and
rye (Vader et al. 2003; Arentz-Hansen et al. 2004). Although
only a very small number of oat-sensitive CD patients exist
that react to these epitopes, they attained much attention and
caused reluctance in oat consumption by coeliac sufferers.
Recently, further in vitro study results raised questions whether
toxicity in oats may have been overlooked, which would have
implications on whether promotion of oat consumption by CD
patients is justified. To shed light on this issue, Londono et al.
(2013) analysed the presence of known epitopes from wheat,
barley and rye in avenins. This analysis confirmed that none of
the epitopes from gluten of wheat, barley and rye are present
in oat avenins and suggests that reactions in such patients are
attributed, most likely, to a rare reaction to the specific oat
avenins. These data give an additional support to the general
safety of oats for CD patients. Recently, Kaukinen et al. (2013)
further confirmed the safety of oats for CD sufferers from a
long-term consumption study involving over 100 coeliac
volunteers. Oat consumption of 20g (range 1-100g) per day for
eight years resulted in significantly better mucosal morphology
when oats were consumed in higher amounts over a longer
period, as compared to the controls that used a gluten-free diet
without oat during this period, which is suggested to be the
positive effect of oat fibre intake. These data also confirmed
earlier studies that long-term ingestion of oats is safe.
(Kaukinen et al, 2013).
In summary, oats lack all coeliac diseaseinducing gluten fragments of wheat, rye
and barley. The real positive effects of oat
consumption by coeliac sufferers by far
outweigh the minor potential hazards.
oats for health
19
Oats & ALLERGY/INTOLERANCE continued...
Why are oats not permitted to be considered gluten free in Australia and
NZ but may be recommended for CD patients in Europe and the USA?
Because of the general safety of oats, EU regulation allows oats in foodstuffs for people with CD when it is produced,
prepared and processed in a way to avoid contamination by wheat, rye and barley and the gluten content of these products is
below 20 ppm (EC 41/2009). Efforts have been made in several Nordic countries (Sweden, Finland) where they guarantee a
gluten-free supply chain for oats and consequently, over 70% of CD patients eat oats regularly as a healthy component of their
gluten-free diet (Salovaara et al., 2010). This was also recently established in The Netherlands with support of the Dutch Celiac
Patient Association. Since August 2013, the USA. allows oats to be sold as gluten-free provided any contamination with gluten
from wheat, barley and rye is below 20 ppm.
In Australia and NZ, however, oats are prohibited from claiming to be gluten free. The Food Standards Code only permits the
use of gluten free claims on products with “no detectable gluten and products that do not contain oats or their products; or
cereals containing gluten that have been malted, or their products”. As modern testing now allows us to detect levels of gluten
to very low levels, this means that products with >20ppm (from contaminating gluten sources) are also prevented from carrying
gluten free claims even though the risk to CD patients may be very low (note that current test methods approved by Codex
Alimentarius cannot reliably test for the presence of inherent gluten, only the presence of contaminating gluten in oats).
What do Coeliac Associations recommend?
Coeliac Australia and Coeliac New Zealand currently recommend that coeliac patients should avoid even uncontaminated
oats because of some coeliac sufferers reacting to oat avenins (Coeliac Research Fund 2008). Coeliac associations from
other countries (e.g. Canada, UK, USA, Finland, The Netherlands), however, suggest that for most coeliac sufferers it is
okay to include uncontaminated oats in the diet. It has been suggested that the decision about whether or not to include
oats should be made on an individual basis (i.e. this should be tested) rather than excluding oats form the diet of all
coeliac patients, recognising that the availability of oats would improve food choices for those on a gluten-free diet
(Canadian Coeliac Association 2013; Coeliac UK 2013).
20
oats for health
21
Anti-inflammatory properties
of oats
Prof. Mohsen Meydani,
JM USDA-Human Nutrition Research Center on Aging, Tufts University, Boston
Epidemiological evidence suggests
that a high intake of whole grain foods
including wheat, rice, barley, maize
and oats is associated with reduced
risk of coronary heart disease (CHD)
and diabetes.
The high fibre content of whole grains, and more specifically
the high content of beta-glucans, is believed to be the
major contributing factor to their beneficial health effects.
A comprehensive review of literature by Kelly et al. (2007)
provides evidence that the beneficial effect of consuming whole
grains on CHD in clinical intervention trials is mainly limited to
whole grain oats.
Avenanthramides –
bioactive compounds
unique to oats
In addition to their cholesterol lowering effect (see section
‘Oats and cholesterol lowering’), oats have been shown to
improve endothelial function and to reduce blood pressure
(Saltzman et al. 2001) potentially through modulation of
vascular endothelium production of nitric oxide (NO) (Katz
et al. 2001; see section ‘Oats and vascular health’). Oats, in
addition to containing soluble fibres ( -glucan), are a good
source of several antioxidants including vitamin E, phytic acid,
phenolics, and avenanthramides, unique soluble bioactive
compounds not present in any other cereal grains (Collins et al.
1989). Avenanthramides from oats exhibit potent antioxidant
activity in vitro and in vivo (Dimberg et al. 1992; Peterson
et al. 2002; Bratt et al. 2003; Chen et al. 2005; Ren et al.
2011). Combined with vitamin C, they synergistically inhibited
LDL -cholesterol oxidation in vitro, a major factor involved
in the formation of atherosclerotic lesions. More than 20
different forms of avenanthramides are present in oat extract.
The three major forms are A, B, and C (see Figure 5, Peterson
et al. 2002), and avenanthramide-C often makes up about
one-third of the total concentration of avenanthramides in oat
grain. While the bioavailability of avenanthramides has been
shown in animals and in humans (Chen et al. 2007; Chen et al.
2004), its metabolism and tissue distribution in the human body
is currently unknown.
22
Antioxidant,
antihistamine and antiinflammatory properties
of avenanthramides
In vivo and in vitro studies have shown that avenanthramides possess
antihistamine and anti-inflammatory properties (Chen et al. 2007).
For centuries, oatmeal has been topically used as a
remedy to treat skin irritation from poison ivy, sunburn,
eczema, and psoriasis.
Oat colloidal extract (very finely ground oats suspended in water)
containing avenanthramides has also proved to have antihistamine
and anti-irritation activity (Kurtz & Wallo 2007). Avenanthramides
and dihydro-avenanthramides, a synthetic derivative, reduce
histamine release from mast cells and consequently reduce
associated skin disorders like itching, redness, and wheals, resulting
in lower use of corticosteroids (Heuschkel et al. 2008; Cerio
et al. 2010). In addition to their antioxidant and antihistamine
activities, oat avenanthramides also possess anti-inflammatory
properties. While the anti-itching property of oats and oatmeal
has been recognised for many years, recent reports provided
molecular evidence for the mechanism by which oats may exert their
soothing effect on irritated skin. Avenanthramides can modulate
cellular signalling pathways that govern cellular responses during
inflammation. In a cell culture system using human aortic endothelial
cells, the potential health benefit effect of avenanthramides was
found to be mediated by molecular processes that are known to play
an important role in the inflammation of arteries and the development
of atherosclerosis (Liu et al. 2004).
Vascular benefits of avenanthramides
When the levels of fat and cholesterol increase in circulation,
certain locations in blood vessels become susceptible to
inflammation, which attracts and attaches circulating immune
cells to the site of inflammation. This eventually leads to
formation of atherosclerotic lesions in the arteries. For this
process to occur, several inflammatory mediators [such as IL-1,
IL-6, IL-8 and monocyte chemotactic protein (MCP)-1] and
adhesion molecules [including intracellular adhesion molecule
(ICAM)-1, vascular cell adhesion molecule (VCAM)-1, and
E-selectin] need to be expressed. Avenanthramides enriched
extracts of oats have been shown to inhibit expression of
these molecules in the endothelial cells in culture and other
tissues by suppressing NF- KB, an important transcription factor
in inflammation (Collins 1993; Collins & Cybulsky 2001;
Collins et al. 1995). In addition, oatmeal extract containing
avenanthramides suppresses production of prostaglandin E2,
which is another mediator in inflammation (Alexandrescu et al.
2007; Sur et al. 2008).
We also examined the antiproliferative effect of avenanthramides
on several cancer cell lines and found that they are effective
in inhibiting proliferation of colonic cancer cell lines, but not
prostate or breast cancer cells (Guo et al. 2010).
Taken altogether, whole oats, oat bran, oatmeal and colloidal
of oats, as well as avenanthramides enriched extracts of oats
(currently not available in Australia or New Zealand, but in
other countries including Canada) have the potential to
provide a broad range of health benefits through antioxidant,
anti-inflammatory and antihistamine activities, which complement
the already established cholesterol lowering properties of oats.
Thus, regular inclusion of foods containing oats and oat products
in the daily diet may reduce the risk of CHD and several
diseases associated with inflammation.
In addition to their anti-inflammatory properties, oat
avenanthramides have been shown to suppress proliferation of
vascular smooth muscle cells, a process that is known to be a
major contributing factor in the development of atherosclerosis.
This effect of avenanthramides is mediated through suppression
of phosphorylation of retinoblastoma protein (pRb) in the cell
cycle (Nie et al. 2006a+b).
FIGURE 5: Chemical structure of major
Avenanthramides (see Peterserson et al. 2002)
HO
O
R
N
H
H
O
O
Avenanthramide - a R=H
Avenanthramide - b R=OCH3
Avenanthramide - c R=OH
O
H
oats for health
23
oat consumption &
glucose control
Dr Peter Clifton,
Professor of Nutrition, University of South Australia
Soluble dietary fibre in carbohydrate-rich foods influences the glycaemic response
after a meal. In particular, β- glucans present in oats (and also barley) have
been widely studied for their health benefits including their ability to reduce
post-prandial glucose levels (Tosh 2013).
Oat -glucans, in their native state, are very high molecular-weight (MW) polysaccharides that exhibit high viscosities at low
concentrations (Ren et al. 2003). The degree of glycemic lowering is related to the MW of the oats (Tosh et al. 2008) as
well as the total dose.
Consumption of -glucan increases the viscosity of the meal bolus in the stomach (Marciani et al. 2001), which reduces
mixing of the food with digestive enzymes and delays gastric emptying (Tosh 2013). Increased viscosity also slows the
absorption of glucose (Braaten et al. 1991, Panahi et al. 2007), further contributing to reduced post-prandial glucose
levels. -glucan is also easily fermented by the gut microbiota, producing short-chain fatty acids including actetate,
propionate and butyrate, which may affect the post-prandial glucose at subsequent meals (Tosh 2013).
BETA-GLUCANS ARE PROVEN TO LOWER
GLYCAEMIC RESPONSE
The positive effect of β -glucan has been confirmed in the scientific opinion of the
European Food Safety Authority (EFSA), which advises the European Commission on
matters relating to health claims.
EFSA recognised that a cause and effect relationship between oat and barley -glucans and a reduction of post-prandial
glycaemic response has been established. However, EFSA suggests that in order to obtain the claimed effect, 4 g of β
-glucans from oat or barley for each 30 g of available carbohydrates should be consumed per meal (EFSA 2011), a level
that is likely to be difficult to achieve (Tosh 2013). Health claims relating to -glucans and blood glucose regulation have yet
to be evaluated in Australia and New Zealand, however, the list of health claims is continuously updated.
Tosh (2013) reviewed all the available randomised, double-blind, placebo-controlled clinical trials on oat and barley
-glucan and post-prandial blood glucose response. The studies using oat-based products are shown in Table 3 (see over).
The effect of -glucans on the area under the post-prandial blood-glucose curve (AUC), which is a measure used when
determining the glycaemic index (GI) of a food, as well as the peak blood-glucose rise, another useful measure of
post-prandial blood-glucose response, were investigated. The study findings are shown on the next page.
24
oats for health
25
Oat CONSUMPTION & GLUCOSE CONTROL
continued...
STUDY FINDINGS
Altogether, 24 studies tested 55 separate oat products:
69%
of the oat treatments
showed a reduction in
the AUC and/or GI
72%
71%
showed a reduction in
peak blood-glucose rise
Insulin was not elevated in any studies, and of
the studies that used ≥4g -glucan from oats
and barley 72% showed a lowering of the
insulin response
The findings indicate that the amount of -glucan consumed, rather than the ratio of -glucan to available carbohydrate, is important
for blood glucose regulation, suggesting that the EFSA claim may be too restrictive. Overall, Tosh proposed that a dose of 4g
-glucan in processed products predict a physiologically relevant decrease equivalent to 15 GI units and people would achieve
this intake by consuming several different oat products throughout the day. There was a correlation between the increase in viscosity
achieved by the oat product and glucose lowering (Tosh 2013). Lower amounts of unprocessed high MW oat -glucan (1.8-2.1g)
are needed to achieve a similar effect to 4g of processed, lower MW beta-glucan. These levels of high MW beta-glucan would
typically be found in a large portion of low processed oat products such as oat tempe and oat bread made with coarse boiled oats.
Breaking down the oat -glucan to smaller fragments reduces the effectiveness of -glucan (Tosh et al. 2008). Food-processing
methods that reduce the molecular weight and solubility of oat -glucan reduces its ability to lower blood glucose (Wolever et al.
2010). This has also been found in the recent review by Tosh (2013), where the average reduction of AUC was more pronounced
with intact boiled grains compared to processed products (including porridge). Nevertheless, both processed and unprocessed
oat-based products led to significant reductions in blood glucose levels (Tosh 2013). There is also evidence that suggests that
type 2 diabetics benefit just as much as non diabetics from the consumption of oat products (Kabir et al. 2002, Jenkins et al. 2002,
Tappy et al. 1996).
In conclusion, there is convincing evidence that oat β -glucan
lowers postprandial glucose response, which is considered to
be beneficial for all people at all stages of life. It may be
particularly useful in those with risk factors for type 2 diabetes
in preventing progression to type 2 diabetes, as glycemic
load is a predictor of disease progression.
/4
3
of the oat and barley products that contained ≥4g -glucan showed significant reductions
in post-prandial glucose despite the available carbohydrate dose being clearly above the
30g dose suggested by EFSA (51g on average).
26
oats for health
27
TABLE 3: Studies investigating the effect of oat products on blood glucose response (adapted from Tosh 2013)
Food format
Subjects
n
Betaglucan
dose
(g)
AC
dose
(g)
Change
in AUC
(mmol
·min/l)
Significant
Change
in GI
values
Peak
Change
sig.
First author and source
Oat bran muffins
Food format
Subjects
n
ß-G
dose
(g)
AC
dose
(g)
Change
in AUC
(mmol
·min/l)
sig
Change
in GI
values
Peak
Change
sig.
First author and source
Oat bran drink
18
0.3 a
72b
3
No
No
Behall, Diabetes Care 2006; 29:976-81
10
2
50
−26.9
n/a
−16.3
Yes
Mäkeläinen, Eur J Clin Nutr 2007; 61:779-85
18
0.9 a
72b
5
No
No
Behall, Diabetes Care 2006; 29:976-81
10
4
50
−68.8
n/a
−41.7
Yes
Mäkeläinen, Eur J Clin Nutr 2007; 61:779-85
18
3.7 a
72b
−26
No
Yes
Behall, Diabetes Care 2006; 29:976-81
10
6
50
−60.6
n/a
−36.7
Yes
Mäkeläinen, Eur J Clin Nutr 2007; 61:779-85
11
12
50
−73
Yes
Yes
Lan-Pidhainy, Cereal Chem 2007; 84:512-7
10
4
50
−58.9
n/a
−35.7
Yes
Mäkeläinen, Eur J Clin Nutr 2007; 61:779-85
Yes
Lan-Pidhainy, Cereal Chem 2007; 84:512-7
18
5
75
−40
No
−40
Ulmius, Genes Nutr 2011; 6:429-39
9
3.3 a
50
−40.4
No
−15
Nilsson, Am J Clin Nutr 2008; 87:645-54
19
3
50
−80.0
Yes
−40
Yes
Granfeldt, Eur J Clin Nutr 1995; 49:189-99
−18.3
Yes
De Angelis, Br J Nutr 2007; 98:1196-205
Yes
Juntunen, Am J Clin Nutr 2002; 75:254-62
Yes
Liljeberg, Eur J Clin Nutr 1992; 46:561-75
No
Regand, J Agric Food Chem 2009; 57:8831-38
previously frozen
11
8
50
−79
Yes
medium MW
10
4
50
−26
No
Thosh, Cereal Chem 2008; 85:211-7
medium MW
10
4
50
−44
Yes
Thosh, Cereal Chem 2008; 85:211-7
medium MW
10
8
50
−49
Yes
Thosh, Cereal Chem 2008; 85:211-7
medium MW
10
8
50
−74
Yes
Thosh, Cereal Chem 2008; 85:211-7
Breads
high MW
10
4
50
−50
Yes
Thosh, Cereal Chem 2008; 85:211-7
3.9
50
−35
Yes
10
8
50
−76
Yes
Thosh, Cereal Chem 2008; 85:211-7
Sourdough bread
with oat fibre
15
high MW
previously frozen
11
8
50
−66
Yes
Yes
Lan-Pidhainy, Cereal Chem 2007; 84:512-7
10
5.4
50
−48
Yes
previously frozen
11
8
50
−48
Yes
Yes
Lan-Pidhainy, Cereal Chem 2007; 84:512-7
Rye bread with oat
ß-glucan concentrate
previously frozen
11
12
50
−68
Yes
Yes
Lan-Pidhainy, Cereal Chem 2007; 84:512-7
Bread with coarse
boiled oats
10
2.1 a
50
−15.6
Yes
previously frozen
11
12
50
−63
Yes
Yes
Lan-Pidhainy, Cereal Chem 2007; 84:512-7
Oat crisp bread
(medium MW)
12
4
64
−11
No
Oat bran cereal
Boiled oat kernels
medium MW
12
8.3
31
−46
Yes
−46
Yes
Brummer, Cereal Chem 2012; 89:255-61
Pasta
medium MW
12
8.7
31
−64
Yes
−44
Yes
Brummer, Cereal Chem 2012; 89:255-61
Oat bran fettuccini
10
5.2
54.2
−4.5
Yes
medium MW
12
8.4
31
-65
Yes
-27
Yes
Brummer, Cereal Chem 2012; 89:255-61
high MW
12
8.6
31
−56
Yes
−56
Yes
Brummer, Cereal Chem 2012; 89:255-61
Oat pasta
(medium MW)
12
4
42
−7
No
9
3.3 a
50
−23.6
No
−11
No
Granfeldt, Eur J Clin Nutr 1995; 49:189-99
11
6
75
−39
Yes
19
3
50
−16.7
No
No
Granfeldt, Am J Clin Nutr 1994; 59:1075-82
Glucose drink with
oat extract
13
4a
50
−29.3
Yes
Yes
Granfeldt, Am J Clin Nutr 1994; 59:1075-82
Oat tempe
13
1.8
25
−79
Yes
12
4
32.7
−15.5
Yes
Yes
Hlebowicz, J Am Coll Nutr 2008; 27:470-5
Pudding with
oat flour
10
3.23 a
50
−35
Pudding with
oatmeal
10
73.7b
50
Oat ß-glucan
isolate gel
10
−62
Oat bran
20
Oat extract
−6.7
Holm, Eur J Clin Nutr 1992; 46:629-40
No
Regand, J Agric Food Chem 2009; 57:8831-38
Other
Oat bran muesli
Oat granola
medium MW
12
6.2
38
−28
Yes
Yes
Regand, Food Chem 2011; 129:297-304
medium MW
12
6.3
60
0
No
No
Regand, Food Chem 2011; 129:297-304
high MW
12
4
44
−29
No
Yes
Regand, J Agric Food Chem 2009; 57:8831-38
high MW
12
6.2
38
−35
Yes
Yes
Regand, Food Chem 2011; 129:297-304
high MW
12
6.3
60
−33
Yes
Yes
Regand, Food Chem 2011; 129:297-304
9
3.3 a
50
−11.5
No
−7
No
Granfeldt, Eur J Clin Nutr 1995; 49:189-99
9
2.1 a
35.5
−7.1
No
5.8
No
Liljeberg, J Nutr 1996; 126:458-66
12
4
50
−29.4
Yes
−24
Panahi, J Am Coll Nutr 2007; 26:639-44
−37
Yes
Alminger, Eur J Clin Nutr 2008; 47:294-300
Yes
Yes
Behall, J Am Coll Nutr 2005; 24:182-8
−35
Yes
Yes
Behall, J Am Coll Nutr 2005; 24:182-8
Yes
−35
Yes
Yes
Braaten, Am J Clin Nutr 1991; 53:1425-30
3.23 a
50
−35
Yes
No
Hallfrisch, Cereal Chem 2003; 80:80-3
20
73.7b
50
−35
Yes
No
Hallfrisch, Cereal Chem 2003; 80:80-3
Wholemeal
oatflakes
12
−49
Yes
−35
Yes
No
Hlebowicz, Nutr J 2007; 6:22
Cream of wheat+oat
ß-glucan isolate
9
11.3
50
−35
Yes
−48
Oat porridge
high MW
12
4
43
−37
No
oat bran porridge
9
8.8
60
−54
Yes
Hätönen, Am J Clin Nutr 2006; 84:1055-61
Yes
−38
Regand, J Agric Food Chem 2009; 57:8831-38
Wood, J Agric Food Chem 1990; 38:753-57
−40
Wood, J Agric Food Chem 1990; 38:753-57
Abbreviations: AC, available carbohydrate; beta- G, -glucan; MW, molecular weight; n/a, not available, AUC, area under the curve; significant, statistically significant;
GI, glycemic index; a Soluble fibre measured; b 1g AC/kg body weight, average given. c 1 h AUC data reported.
28
oats for health
29
OATS & CHOLESTEROL LOWERING
TABLE 4: Permitted health claims relating to β -glucan/oats -glucan and cholesterol lowering
Dr Alastair Ross, Chalmers University of Technology, Gothenburg, Sweden
Region
High circulating LDL cholesterol is one of the most common markers of cardiovascular
disease risk used in clinical practice, and people with high LDL cholesterol are often
given drugs and/or advised to adapt their diet to eat more foods that can lower
cholesterol. As no drugs are without side effects, the latter option can be especially
attractive in cases of people with a family history of cardiovascular disease or mildly
elevated LDL cholesterol, who wish to take proactive preventative measures.
Beta-glucans in
oats help lower
cholesterol levels
Oats are one of the few foods that are proven to lower blood
cholesterol levels, and where there is a sound understanding
of how this happens. Oats, like barley, contain high amounts
of a soluble fibre called -glucan (see Table 2). -glucan is
not digested, but forms a gel inside the intestines, which both
inhibits the absorption of dietary cholesterol and binds bile
acids that are secreted to solubilise the fats that we eat. Bile
acids are synthesised from cholesterol in the liver, so losing
bile acids through their binding to -glucan, leads to more
liver cholesterol being used for synthesising new bile acids.
This double action of preventing cholesterol absorption and
increasing internal cholesterol turnover has the concrete action
of reducing the amount of cholesterol transported throughout
the body (i.e. LDL-cholesterol). These mechanisms have been
demonstrated in many studies in humans (Agot et al. 1995;
Ellegård & Andersson, 2007).
European Union
-glucans contribute to the
maintenance of normal blood
cholesterol levels
The effect of oats on cholesterol appears to be dose
dependent – that is, the more oats (and -glucan) is eaten,
the greater the cholesterol lowering effect is (this is provided
everything else is equal, e.g. viscosity) (Wolever et al. 2010),
with a maximum effect around 3-4 g beta-glucan per day
(Tiwari & Cummings 2011). The overall effect of 3 g/day of
oat -glucan is a 0.23 mmol/L reduction in total cholesterol
and 0.21 mmol/L reduction in LDL, based on studies including
a total of 1080 subjects. This 5 % decrease in LDL-cholesterol
is considered to be clinically significant. No reduction of HDL
cholesterol was reported from these studies (EFSA 2010).
Unsurprisingly, most studies show that reduction of total and
LDL cholesterol is greater in those people starting with higher
cholesterol. These amounts of -glucan translate to about
60g of oats per day, and an effect on cholesterol would be
expected after 1-2 months.
Australia &
New Zealand
USA
Condition
The claim may be used only for food which contains at least 1g of -glucans
from oats, oat bran, barley, barley bran, or from mixtures of these sources per
quantified portion.
In order to bear the claim information shall be given to the consumer that the
beneficial effect is obtained with a daily intake of 3g of -glucans from oats,
oat bran, barley, barley bran, or from mixtures of these beta-glucans.
Oat -glucan has been shown to
lower/reduce blood cholesterol.
High cholesterol is a risk factor
in the development of coronary
heart disease
The more oats, the
greater the effect
Information shall be given to the consumer that the beneficial effect is obtained
with a daily intake of 3g of oat -glucan.
The claim can be used for foods which provide at least 1g of oat -glucans per
quantified portion.
-glucan reduces dietary and
biliary cholesterol absorption
(general level claim)
The food must contain one or more of the following oat or barley foods: oat bran;
whole grain oats; or whole grain barley.
-glucanβ reduced blood
cholesterol (high level claim)
In addition, the following dietary context statements are required: diet containing
3g -glucan; diet low in saturated fatty acids.
The food must contain at least 1g per serving of -glucan from the foods listed.
In order to carry a health claim, a food must also meet the nutrient profiling
scoring criteria set out in the standard.
Soluble fibre from foods such as
[name of soluble fibre source], as
part of a diet low in saturated fat
and cholesterol, may reduce the
risk of heart disease.
The food product must include one or more of the following whole oat or barley
foods: 1) oat bran, 2) rolled oats, 3) whole oat flour, 4) whole grain barley or dry
milled barley, and the whole oat or barley foods must contain at least 0.75g of
soluble fibre per RACC of the food product; or
Oatrim that contains at least 0.75g of beta-glucan soluble per RACC of the
food product.
Eligible sources of soluble fibre: -glucan from oats and barley.
Canada
Several countries allow health claims for the effect of oats
(or oat -glucan) on cholesterol lowering – including the
European Union, which has the most stringent food health claim
requirements worldwide (see Table 4).
Eating oats uncooked (e.g. as muesli) or as porridge has
no negative/deleterious effect on their cholesterol lowering
properties, though processing methods that involve fermentation
(e.g. bread baking) will break down the -glucan (Åman et
al. 2004). Oat -glucan can be isolated and purified, and
added as an ingredient to food, and provided it has not been
fermented, still has the cholesterol lowering properties (Wolever
et al. 2010). Purified -glucan tends to be expensive however.
Claim
[Name and serving size of food]
provides X % of the daily amount
[3g] of the fibres shown to help
reduce/lower cholesterol.
Eligible sources of -glucan are oat bran, rolled oats (also known as oatmeal), and
whole oat flour.
Contain at least 0.75g -glucan per serving.
Also has to meet other nutrient standards relating to sodium, vitamins/minerals,
cholesterol, alcohol and saturated fatty acids.
Sources: European Commission 2013; Food Standards Australia New Zealand 2013; US Food and Drug Administration 2009; Health Canada 2010
For more information
For more information on oats and cholesterol lowering, including detailed information on key studies,
see brochure on Oats for cholesterol lowering: A research summary for health professionals by Dr Peter Williams.
30
oats for health
31
Oats & cholesterol lowering continued...
FIGURE 6: Oats reduce cardiovascular
risk by interfering with cholesterol
absorption, and other mechanisms
may also play a role.
Oats help control cholesterol
levels in more than one way
3g/day or more of β
-glucans from oats will
prevent absorption of
dietary cholesterol and
bind bile acids, causing
increased excretion of
both in the faeces.
The main mechanism whereby oats lower cholesterol is undoubtedly via the
-glucan content, though other mechanisms may also play a role.
Fat metabolism is highly linked to glucose metabolism and insulin sensitivity, and -glucan also has an effect on dampening the blood
glucose response after a meal (EFSA 2011). Total body fat and fat distribution are also key risk factors for cardiovascular diseases, and
one study found that eating 80 g of oat-based breakfast cereal a day for 12 weeks led to reduced waist circumference (1.4 cm after
12 weeks) along with a 4.4% decrease in LDL cholesterol, compared to an iso-energetic placebo control (Maki et al. 2010). Weight
reduction remains one of the best ways of reducing blood cholesterol and cardiovascular disease risk, though more studies would be
needed to confirm that oats have additional benefits on weight reduction or loss of body fat over and above energy/calorie restriction.
Whole grain-rich diets that include oats, as well as other whole grains such as wheat
and rice, have also been demonstrated to lower LDL cholesterol (Ross et al. 2011) and blood
pressure (Tighe et al. 2010), an additional risk factor for cardiovascular disease.
Cholesterol
from the diet or
made in the liver
is used to make
bile acids.
While there is a lot of focus on the -glucan content of oats as the mediator of health benefits, there are likely other oat factors that
contribute to their health benefits, including the grain structure and phytochemicals.
At the moment, nutrition science is at the beginning of grasping the importance of the gut microbiota in maintaining health, and recent
evidence has pointed to the gut microbiota being a key factor in whether diet leads to cardiovascular disease or not (Zhang et al.
2011). The dietary fibre from oats is readily fermentable by the bacteria in the large intestine (colon), with the short chain fatty acids
(SCFAs) acetate, propionate and butyrate being major by-products. These SCFAs have been suggested to influence lipid metabolism
in both the intestine and liver (Wong et al. 2006; Marcil et al. 2003). Improving gut integrity is another possible area where oats
may have a protective role against metabolic diseases (Keshavarzian et al. 2001; Ross et al. 2013), though again human studies are
required to confirm this hypothesis.
Overall evidence that eating a significant amount of oats
and β -glucan from oats each day lowers blood cholesterol is strong.
Alongside the general recommendation to choose whole grains
over refined grains (NHMRC, 2013), regular consumption
of oats is a scientifically supported way of reducing
risk for cardiovascular disease.
Bile acids
are secreted into
the small intestine
to solubilise
dietary fat.
-glucans in the
colon are fermented
to short chain fatty
acids, which may
decrease cholesterol
synthesis in
the liver.
Bile acids
are bound to
-glucans and
excreted.
32
oats for health
33
OATS & VASCULAR HEALTH
Dr Kristina Andersson, Dr Per Hellstrand, Dept. Experimental Medical Science, Lund University, Sweden
Most focus regarding vascular effects of oats has been on its cholesterol-lowering
properties, mainly ascribed to the soluble fibres in oats, -glucans (see section ‘Oats
and cholesterol lowering’). There might however be other components in oats that
can influence atherosclerosis development, the underlying cause of cardiovascular
diseases such as myocardial infarction and stroke.
Atherosclerosis is a complex inflammatory process in the vascular wall, engaging in particular the endothelial cells lining
the inner surface of the vessel wall and the smooth muscle cells forming its muscular coat. This process is multifactorial,
involving oxidative stress and endothelial dysfunction as well as immune cells, pro-inflammatory molecules, triglycerides and
circulating cholesterol carried by low density lipoprotein (LDL) particles (see Figure 7). Various dietary components in oats
have the potential to exert anti-oxidative or anti-inflammatory effects and to beneficially affect endothelial function.
The antioxidative properties of oats
The contents of proteins and lipids in oats are relatively high
compared with other cereals (Drzikova et al. 2005, Ryan et al.
2007, Zhou et al. 1999).
Various anti-oxidative components,
such as vitamin E (tocopherols and
tocotrienols), phenolic compounds
(e.g. the oat-specific avenanthramides),
phytic acids, sterols and flavonoids
protect the oat grain lipids from oxidation
(Peterson 2001).
The free-radical scavenging properties might also be beneficial
for the human body when oats and other antioxidant-rich foods
such as fruits and vegetables are consumed (Ryan et al. 2007,
Zadernowski et al. 1999). In the formation of an atherosclerotic
lesion, it is mainly the oxidized form of LDL (oxLDL) that is
engulfed by macrophages in the blood vessel wall (Libby et
al. 2011). Dietary antioxidants therefore offer the potential of
limiting the atherosclerosis process.
34
Extracts from oats, as well as isolated oat phenolics, reduce
oxidation of LDL particles in vitro (Chen et al. 2007, Gray et
al. 2002, Handelman et al. 1999). However, when similar
extracts were given to either hamsters or humans, and LDL
particles isolated from the subjects were oxidised in vitro, no
protective effect of the ingested extracts could be detected
(Chen et al. 2007, Chen et al. 2004). In accordance with
this, ingestion of whole oats in a human study did not lead
to reduced levels of biomarkers for oxidative stress (oxLDL,
malondialdehyde) (Maki et al. 2007).
On the other hand, there are in vivo reports showing that
intake of avenanthramides and avenanthramide-rich extracts
can stimulate the body’s own oxygen scavenging system in
both man, mice and rats, with increased levels and activity of
endogenous enzymes such as superoxide dismutase (SOD),
reduced glutathione (GSH), and glutathione peroxidase (GPx)
– all protecting the organism from oxidative damage (Chen
et al. 2007, Ji et al. 2003, Liu et al. 2011, Ren et al. 2011; see
section ‘Anti-inflammatory properties of oats’ for more details).
Further studies are needed to clarify if higher levels of bioactive
components with anti-oxidative properties than the levels
present in whole oats are needed to produce measurable
effects. It is also possible that whereas some biological
anti-oxidative systems are affected in vivo, others are not.
oats for health
35
Oats & VASCULAR HEALTH continued...
FIGURE 7: The initial steps in atherosclerosis in a simplified
cartoon modified from Andersson & Hellstrand 2012.
Vascular alterations involved in the progress of atherosclerosis are marked
out, as well as the potential steps at which oats can interfere with the
atherosclerosis process (indicated by a yellow box). LDL, low density
lipoprotein; oxLDL, oxidized LDL, eNOS, endothelial nitric oxide synthase;
NO, nitric oxide.
Inflammation
In vitro experiments show that oat-specific polyphenols
avenanthramides reduce endothelial cell production of
pro-inflammatory cytokines
Adhesion of monocytes & macrophages
Vascular
Lumen
Both cell culture experiments with avenanthramides, and
experiments with mice fed oat bran show a reduced expression
of adhesion molecules on the endothelial cell surface.
Inflammation
Increased LDL
Endothelial dysfunction
LDL
Monocyte
NO
Increased LDL
The LDL cholesterol-lowering properties of oats are well
documented from both human and animal studies.
ENOS
Endothelial cells
Adhesion of monocytes
and macrophages
Reactive
oxygen species
Oxidative stress
As mentioned in the section of “Anti-inflammatory properties
of oats”, cell culture experiments have revealed that
avenanthramides reduce the expression of adhesion molecules
like VCAM-1, ICAM-1 and E-selectin on endothelial cell
surfaces, all important for recruiting macrophages to the
vascular wall in the atherosclerosis process. Moreover,
anti-inflammatory effects of oats have been demonstrated in
animal studies in vivo. Mice fed oat bran had reduced levels
of the adhesion molecule VCAM-1 both in the aortic wall and
in plasma, as well as reduced plasma levels of fibrinogen, a
common inflammatory marker related to cardiovascular risk
(Andersson et al. 2010).
Few human studies have addressed the effects of oats on
systemic inflammation. Intake of oat products enriched in
-glucans did not reduce plasma levels of inflammatory
markers such as C-reactive protein (CRP), IL-6, IL-8 or TNF-α
(Queenan et al. 2007, Theuwissen et al. 2009). Also, in type
2 diabetic patients, an oat-enriched diet did not change the
inflammatory status (McGeoch et al. 2013). Despite promising
results from cell culture and animal experiments, more human
studies are needed to allow final conclusions regarding the
anti-inflammatory effects of oats.
36
Blood pressure &
maintenance of
endothelial function
Several human intervention studies have
shown that intake of oats can reduce
blood pressure (He et al. 2004, Keenan et al. 2002,
Maki et al. 2007, Saltzman et al. 2001), and there have
been indications of a greater effect in
obese than in lean persons (Maki et al. 2007).
Furthermore, in a study on hypertensive patients the use of antihypertensive drugs could be reduced in 73% of the patients
after oat cereal consumption, as compared to 42% in a control
cereal group (Pins et al. 2002). It has been suggested that the
reduced blood pressure after oat intake results from reduced
postprandial glucose and insulin levels (Katz et al. 2001, Maki
et al. 2007). In addition, some in vitro studies suggest that
specific oat components can directly influence the endothelial
cells and thereby contribute to lowering blood pressure by
improving endothelial function. In human endothelial cells
avenanthramides increased the expression of endothelial nitric
oxide synthase (eNOS), which generates the vasodilating
agent nitric oxide (NO), a key mediator of multiple effects
protecting against vascular complications (Nie et al. 2006a).
An increased expression of eNOS was also found in the aortas
of mice fed oat bran (Andersson et al. 2010), further supporting
the notion that consumption of oats may help to maintain
endothelial function by increasing the production of NO. In
humans, endothelial dysfunction (impaired flow-induced arterial
dilatation) provoked by a high-fat meal could be prevented by
concomitant oat intake (Katz et al. 2001).
LDL oxidation
Both human and animal studies report that avenanthramide-rich
extracts can stimulate the body’s own oxygen scavenging system,
thereby reducing the level of oxidative stress.
LDL oxidation
Oat extracts and isolated oat phenolics reduce oxidation of LDL
in vitro, but this has not been confromed in vivo.
Macrophage foam
cell formation
Endothelial dysfunction
Both in vitro and in vivo studies support that oats and/or specific
oat components prevent endothelial dysfunction.
Media
Although there is compelling evidence for an antioxidative
effect of isolated oat components, the evidence of activity after
consumption of oats or oat products is still somewhat conflicting
and more research in this area is warranted.
Intima
oxLDL
Oxidative stress
Vascular Smooth Muscle cells
Oats & prevention of cardiovascular disease
an area to be explored further
No epidemiological studies have so far directly addressed the association between
oats consumption and cardiovascular disease (CVD). To date, evidence of a possible
role of oats in CVD mainly comes from experimental and short-term human studies,
the latter primarily focusing on biomarkers such as cholesterol levels. Therefore, no
strong conclusions on the role of oats in association with CVD can be drawn as yet,
but evidence suggests that there may be a benefit of including oats in the diet.
Oats may also help simply by displacing other breakfast foods that may be higher in sodium, saturated fat or total kilojoules.
A handful of experimental animal studies have shown that oat consumption reduces the incidence of atherosclerotic lesions in
blood vessels (Andersson et al. 2010, Delaney et al. 2003, Eussen et al. 2011, Wilson et al. 2002). In these studies it is difficult to
discriminate whether the anti-atherogenic effects originate solely from the reduction of plasma cholesterol or if there are also direct
effects of specific oat components that contribute to the beneficial effect. More studies with isolated oat components or fractions of
whole oats are warranted. From a public health perspective, the ability of oats to reduce plasma (LDL) cholesterol and to reduce
glycaemic response, in combination with its capacity to maintain endothelial function, and its possible anti-oxidative and
anti-inflammatory actions, makes oat consumption a promising approach for the prevention of cardiovascular disease.
oats for health
37
REFERENCES
AEGIC (Australian Export Grains Innovation Centre) (2012). Oats, Australian Grains Note. South
Perth, Western Australia. Available online:
http://www.aegic.org.au/media/17506/aegic_oats_final.pdf (accessed 20 November 2013).
Agot, L, Hallmans, G et al. (1995). Oat -glucan increases bile acid excretion and a fibre-rich
barley fraction increases cholesterol excretion in ileostomy subjects. Am J Clin Nutr 62:12451251.
Alexandrescu, DT, Vaillant, JG & Dasanu, CA (2007). Effect of treatment with a colloidal oatmeal
lotion on the acneform eruption induced by epidermal growth factor receptor and multiple
tyrosine-kinase inhibitors. Clin Exp Dermatol 32:71-74.
Åman, P, Rimsten, L, & Andersson, R (2004). Molecular weight distribution of -glucan in oatbased foods. Cereal Chem 81: 356-360.
Andersson, KE and Hellstrand, P (2012). Dietary oats and modulation of atherogenic pathways.
Mol Nutr Food Res 56:1003-1013.
Andersson, KE, Svedberg, KA, et al. (2010). Oats (Avena sativa) reduce atherogenesis in LDLreceptor-deficient mice. Atherosclerosis 212:93-99.
Ellegård, L & Andersson, H (2007). Oat bran rapidly increases bile acid excretion and bile acid
synthesis: an ileostomy study. Eur J Clin Nutr 61: 938-945.
European Commission (2013). EU Register of Nutrition and Health Claims. Available online:
http://ec.europa.eu/nuhclaims/ (accessed 21 November 2013).
European Commission (2009). Commission Regulation (EC) No 41/2009 of 20 January 2009
concerning the composition and labelling of foodstuffs suitable for people intolerant to gluten.
Official Journal of the European Union, L16:3-5.
Eussen, SR, Rompelberg, CJ, et al. (2011). Simultaneous intake of oat bran and atorvastatin
reduces their efficacy to lower lipid levels and atherosclerosis in LDLr-/- mice.
Pharmacol Res 64, 36-43.
Fayet-Moore, F, Ridges, L,et al. (2012). Impact of breakfast skipping on Australian children’s
nutrient intake. Australasian Med J 5:675.
Fardet, A. (2010). New hypotheses for the health-protective mechanisms of whole-grain cereals:
what is beyond fibre? Nutr Res Rev 23(1): 65-134.
Keshavarzian, S, Choudhary, E et al. (2001). Preventing gut leakiness by oats supplementation
ameliorates alcohol-induced liver damage in rats. J Pharmacol Experiment Therapeut 299:442448.
Kurtz, ES and Wallo, W (2007). Colloidal oatmeal: history, chemistry and clinical properties. J
Drugs Dermatol 6:167-70.
Libby, P, Ridker, PM, et al. (2011). Progress and challenges in translating the biology of
atherosclerosis. Nature 473:317-325.
Liu, S, Yang, N, et al. (2011). Antioxidant Effects of Oats Avenanthramides on Human Serum.
Agric Sci in China 10:1301-1305.
Ross, AB, Bruce, SJ, et al. (2011). A whole-grain cereal-rich diet increases plasma betaine, and
tends to decrease total and LDL-cholesterol compared with a refined-grain diet in healthy subjects.
Br J Nutr 105:1492-1502.
Ross, AB, Godin, JP et al. (2013) Increasing whole grain intake as part of prevention and treatment
of non-alcoholic fatty liver disease. Int J Endocrinol 585876: 1-13.
Ryan, D, Kendall, M, et al. (2007). Bioactivity of oats as it relates to cardiovascular disease. Nutr
Res Rev 20:147-162.
Saluvaara, HO, Kanerva, P, et al. (2010). Oats in the gluten-free diet. Considerations of a
pragmatic policy. In: Second International Symposium on Gluten-Free Cereal Products and
Beverages. Tampere, University of Helsinki, Finland, pp 193-194.
Liu, L, Zubik, L, et al. (2004). The antiatherogenic potential of oat phenolic compounds.
Atherosclerosis 175:39-49.
Saltzman, E, Das, SK, et al. (2001). An oat-containing hypocaloric diet reduces systolic blood
pressure and improves lipid profile beyond effects of weight loss in men and women. J Nutr
131:1465-70.
Londono, DM, Van ‘t Westende, WPC, et al. (2013). Avenin diversity analysis of the genus Avena
(oat). Relevance for people with celiac disease. J Cereal Sci 58:170-177.
Sicherer, SH and Sampson, HA (2010). Food allergy. J Allergy Clin Immunol 125:S116-125.
Arentz-Hansen, H, Fleckenstein, B, et al. (2004). The molecular basis for oat intolerance in
patients with coeliac disease. PLoS Medicine 1:48-92.
Food Standards Australia New Zealand (2013). Australia New Zealand Food Standards Code Standard 1.2.7 - Nutrition, Health and Related Claims. Available online: from www.comlaw.gov.
au/Series/F2013L00054 (Accessed 13 September 2013).
Australian Bureau of Statistics (2012). Year Book of Australia 2012. Available online:
http://www.abs.gov.au/ausstats/[email protected]/mf/1301.0 (accessed 20 November 2013).
Gelinas, P, McKinnon, CM, et al. (2008). Gluten contamination of cereal foods in Canada. Int
JFood Sci Technol 43:1245-1252.
Belobrajdic, DP & Bird, AR (2013). The potential role of phytochemicals in whole grain cereals for
the prevention of type-2 diabetes. Nutr J 12:62.
Gibson, SA & Gunn, P (2011). What’s for breakfast? Nutritional implications of breakfast habits:
insights from the NDNS dietary records. Nutrition Bulletin 36:78-86.
Maki, KC, Galant, R, et al. (2007). Effects of consuming foods containing oat beta-glucan on
blood pressure, carbohydrate metabolism and biomarkers of oxidative stress in men and women
with elevated blood pressure. Eur J Clin Nutr 61:786-795.
Braaten, JT, Wood, PJ, et al. (1991). Oat gum, a soluble fibre which lowers glucose and insulin
in normal individuals after an oral glucose load: comparison with guar gum. Am J Clin Nutr
53:1425–1430.
Gilissen LIWJ, Van der Meer, IM, & Smulders, MJM (2008). Beyond Celiac Disease Toxicity.
Detoxified and non-toxic grains. In: Frontiers in Cemica Disease, Fasano A et al (eds). Pediatr
Adolesc Med Basel, Karger 12: 139-147.
Marciani, L, Gowland, PA, et al. (2001). Effect of meal viscosity and nutrients on satiety,
intragastric dilution, and emptying assessed by MRI. Am J Physiol Gastrointest Liver Physiol
280:G1227–G1233.
Bratt, K, Sunnerheim, K, et al. (2003). Avenanthramides in oats (Avena sativa L.) and
structure-antioxidant activity relationships. J Agric Food Chem 51:594-600.
Grains & Legumes Nutrition Council (2013). Nutrient Analysis of Australian Grown Grains and
Legumes. Unpublished.
Marcil, V, Delvin, E, Garofalo, C, Levy, E (2003) Butyrate impairs lipid transport by inhibiting
microsomal triglyceride transfer protein in Caco-2 cells. J Nutr 133: 2180-2183.
Canadian Coeliac Association (2013). Position Statement on Oats. Available online: from
www.celiac.ca/index.php/about-celiac-disease-2/cca-position-statements/position-statementon-oats/ (accessed 11 October 2013).
Gray, DA, Clark, MJ, et al. (2002). Antioxidant Activity of Oat Extracts added to Human LDL
Particles and in Free Radical Trapping Assays. J Cereal Sci 36:209-218.
McGeoch, SC, Johnstone, AM, et al. (2013). A randomized crossover study to assess the effect
of an oat-rich diet on glycaemic control, plasma lipids and postprandial glycaemia, inflammation
and oxidative stress in Type 2 diabetes. Diabet Med doi: 10.1111/dme.12228.
Theuwissen, E, Plat, J, et al. (2009). Consumption of oat beta-glucan with or without plant stanols
did not influence inflammatory markers in hypercholesterolemic subjects. Mol Nutr Food Res 53,
370-376.
Meydani, M (2009). “Potential health benefits of avenanthramides of oats.” Nutr Rev 67(12):
731-735.
Tighe, P, Duthie, G, et al. (2010). Effect of increased consumption of whole-grain foods on blood
pressure and other cardiovascular risk markers in healthy middle-aged persons: a randomized
controlled trial. Am J Clin Nutr 92:733-740.
Cerio, R, Dohil, M,et al. (2010). Mechanism of action and clinical benefits of colloidal oatmeal
for dermatologic practice. J Drugs Dermatol 9:1116-20.
Chen, CY, Milbury, PE, et al. (2004). Avenanthramides and phenolic acids from oats are
bioavailable and act synergistically with vitamin C to enhance hamster and human LDL
resistance to oxidation. J Nutr 134:1459-66.
Chen, CY, Milbury, PE, et al. (2005). Antioxidant capacity and bioavailibility of oat
avenanthramides. FASEB J 19:A1477.
Chen, CY, Milbury, PE, et al. (2007). Avenanthramides are bioavailable and have antioxidant
activity in humans after acute consumption of an enriched mixture from oats. J Nutr 137:1375-82.
Coeliac Research Fund (2008). Position Statement on: The consumption of pure oats by
individuals with coeliac disease. Available online: www.coeliac.org.nz/oats (accessed 11
October 2010).
Coeliac UK (2013). Oats in the gluten-free diet. Accessed 11 October 2013, from
www.coeliac.org.uk/healthcare-professionals/diet-information/oats-in-the-gluten-free-diet.
Collins, FW (1989). Oat phenolics: avenanthramides, novel substituted N-cinnamoylanthranilate
alkaloids from oat groats and hulls. J Agric Food Chem 37:60-6.
Collins, T (1993). Biology of disease: Endothelial nuclear factor-kB and the initiation of the
atherosclerotic lesion. Lab Invest 68:499-508.
Collins, T, Read, MA, et al. (1995). Transcriptional regulation of endothelial cell adhesion
molecules: NF-kB and cytokine-inducible enhancers. FASEB J 9:899-909.
Collins, T & Cybulsky, MI (2001). NF-kB: pivotal mediator or innocent bystander in
atherosclerosis? J Clin Invest 107:255-64.
Delaney, B, Nicolosi, RJ, et al. (2003). Beta-glucan fractions from barley and oats are similarly
antiatherogenic in hypercholesterolemic Syrian golden hamsters. J Nutr 133, 468-475.
Dimberg, LH, Theander, O & Lingnert, H (1992). Avenanthramides-a group of phenolic
antioxidants in oats. Cereal Chem 70:637-41.
Drzikova, B, Dongowski G, et al. (2005). The composition of dietary fibre-rich extrudates from oat
affects bile acid binding and fermentation in vitro. Food Chemistry 90, 181-192.
EFSA (2011). Scientific Opinion on the substantiation of health claims related to beta-glucans
from oats and barley and maintenance of normal blood LDL-cholesterol concentrations (ID 1236,
1299), increase in satiety leading to a reduction in energy intake (ID 851, 852), reduction of postprandial glycaemic responses (ID 821, 824), and ‘digestive function’ (ID 850) pursuant to 13(1)
of Regulation (EC) No 1924/2006. EFSA J 9:2207–2228.
EFSA (2010). Scientific opinion on the substantiation of a health claim related to oat -glucan
and lowering blood cholesterol and reduced risk of (coronary) heart disease pursuant to Article
14 of regulation (EC) No 1924/2006. EFSA J 8: 1885-2000.
38
Grieger, JA & Cobiac, L (2012). Comparison of dietary intakes according to breakfast choice in
Australian boys. Eur J Clin Nutr 66:667-672.
Guo W, Nie L, et al. (2010). Avenanthramides inhibit proliferation of human colon cancer cell
lines in vitro. Nutrition and Cancer 62(8):1007-1609.
Handelman, GJ, Cao, G, et al. (1999). Antioxidant capacity of oat (Avena sativa L.) extracts.
1. Inhibition of low-density lipoprotein oxidation and oxygen radical absorbance capacity. J Agric
Food Chem 47:4888-4893.
Maki, KC, Beiseigel, JM et al. (2010). Whole-grain ready-to-eat oat cereal, as part of a dietary
program for weight loss, reduces low-density lipoprotein cholesteorl in adults with overweight
and obesity more than a dietary program including low-fibre control foods. J Am Diet Assoc
110:205-214.
National Health and Medical Research Council (2013). Australian Dietary Guidelines. Canberra:
National Health and Medical Research Council.
Nie, L, Wise, ML, et al. (2006a). Avenanthramide, a polyphenol from oats, inhibits vascular
smooth muscle cell proliferation and enhances nitric oxide production. Atherosclerosis 186:260-6.
He, J, Streiffer, RH, et al. (2004). Effect of dietary fibre intake on blood pressure: a randomized,
double-blind, placebo-controlled trial. J Hypertens 22:73-80.
Nie, L, Wise, M, et al. (2006b). Mechanism by which avenanthramide-c, a polyphenol of oats,
blocks cell cycle progression in vascular smooth muscle cells. Free Radic Biol Med 41:702-8.
Health Canada (2010). Oat products and blood cholesterol lowering. Available online: http://
hc-sc.gc.ca/fn-an/alt_formats/pdf/label-etiquet/claims-reclam/assess-evalu/oat_avoine-eng.
pdf (accessed 21 November 2013).
NZ Institute for Plant & Food Research, Ministry of Health (2012). The Concise New Zealand
Food Composition Tables, 9th Edition 2012.
Heuschkel, S, Wohlrab, J,et al. (2008). Modulation of dihydroavenanthramide D release and skin
penetration by 1,2-alkanediols. Eur J Pharm Biopharm 70:239-47.
Hoyland, A, Dye, L & Lawton, CL (2009). A systematic review of the effect of breakfast on the
cognitive performance of children and adolescents. Nutr Res Rev 22:220-243.
Index Mundi (2013) Oats production by country. Available online: http://www.indexmundi.com/
agriculture/?commodity=oats&graph=production (accessed 20 November 2013).
Jenkins, AL, Jenkins, DJA et al. (2002). Depression of the glycemic index by high levels of β
-glucan fibre in two functional foods tested in type 2 diabetes. Eur J Clin Nutr 56:622–628.
Ji, LL, Lay, D, et al. (2003). Effects of avenanthramides on oxidant generation and antioxidant
enzyme activity in exercised rats. Nutrition Research 23:1579-1590.
Kabir, M, Oppert, J-M, et al. (2002). Four-week low-glycemic index breakfast with a modest
amount of soluble fibres in type 2 diabetic men. Metabolism 51:819–826.
Katz, DL, Nawaz, H, et al. (2001). Effects of oat and wheat cereals on endothelial responses.
Prev Med 33:476-84.
Panahi, S, Ezatagha, A, et al. (2007). -glucan from two sources of oat concentrates affect
postprandial glycemia in relation to the level of viscosity. J Am Coll Nutr 26:639–644.
Peterson, DM, Hahn, MJ, Emmons, CL (2002). Oat avenanthramides exhibit antioxidant activities
in vitro. Food Chem 79:473-8.
Sur, R, Nigam, A, et al. (2008). Avenanthramides, polyphenols from oats, exhibit anti-inflammatory
and anti-itch activity. Arch Dermatol Res 300:569-74.
Szajewska, H & Ruszczynski, M (2010). Systematic review demonstrating that breakfast
consumption influences body weight outcomes in children and adolescents in Europe. Critical
Reviews in Food Science and Nutrition 50: 113-119.
Tappy, L, Gugolz, E, Würsch, P (1996). Effects of breakfast cereals containing various amounts of
beta-glucan fibres on plasma glucose and insulin responses in NIDDM subjects. Diabetes Care
19:831-834.
Tosh S (2013). Review of human studies investigating the post-prandial blood-glucose lowering
ability of oat and barley food products. Eur J Clin Nutr 67:310-317.
Tosh, SM, Brummer, Y, et al. (2008). Glycemic response to oat bran muffins treated to vary
molecular weight of -glucan. Cereal Chem 85: 211–217
US Food and Drug Administration (2009). Guidance for Industry: A Food Labelling
Guide (11. Appendix C: Health Claims). Available online: http://www.fda.gov/Food/
GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/LabelingNutrition/
ucm064919.htm (accessed 21 November 2013).
Vader, LW, Stepniak, DT, et al.(2003). Characterization of cereal toxicity for celiac disease
patients based on protein homology in grains. Gastroenterol 125:1105-1113.
Peterson, D (2001). Oat Antioxidants. J Cereal Sc 33:115-129.
Varjonen, E, Savolainen, J, et al. (1994). IgE-binding components of wheat, rye, barley and oats
recognized by immunoblotting analysis with sera from adult atopic dermatitis patients. Clin Exp
Allergy 22:481-489.
Pins, JJ, Geleva, D et al.. (2002). Do whole-grain oat cereals reduce the need for antihypertensive
medications and improve blood pressure control? J Fam Pract 51:35-359.
Webster, FH and Wood, PJ (2011). Oats. Chemistry and Technology. AACC International, Inc., St
Paul, Minnesota, USA.
Primary Industries Standing Committee. Grains Industry National Research, Development and
Extension Strategy. 2011 Australia.
Williams, P (2007). Breakfast and the diets of Australian children and adolescents: an analysis of
data from the 1995 National Nutrition Survey. International Journal of Food Science and Nutrition
58(3):201-16.
Pulido, O, Gillespie, Z, et al. (2009). Introduction of oats in the diet of individuals with celiac
disease: a systematic review. Adv Food Nutr Res 57:235-285.
Queenan, KM, Stewart, ML, et al. (2007). Concentrated oat beta-glucan, a fermentable fibre,
lowers serum cholesterol in hypercholesterolemic adults in a randomized controlled trial. Nutr J
6:6.
Koukinen, K, Collin, P et al (2013) Long-term consumption of oats in adult Celicac disease
patients. Nutrients 5: 4380-4389
Regand, A, Chowdhury, Z, et al. (2011). The molecular weight, solubility and viscosity of oat
beta-glucan affect human glycemic response by modifying starch digestibility. Food Chem
129:297–304.
Keenan, JM, Pins, JJ, et al. (2002). Oat ingestion reduces systolic and diastolic blood pressure in
patients with mild or borderline hypertension: a pilot trial. J Fam Pract 51:369.
Regand, A, Tosh, SM, et al. (2009). Physicochemical properties of -glucan in differently
processed oat foods influence glycemic response. J Agric Food Chem 57:8831–8838.
Kelly, SA, Summerbell ,CD, et al. (2007). Whole grain cereals for coronary heart disease.
Cochrane Database Syst Rev 18:CD005051.
Ren, Y, Ellis, PR, et al. (2003). Dilute and semi-dilute solution properties of (1–3)(1–4)-β-D-glucan, the endosperm cell wall polysaccharide of oats (Avena sativa L.). Carbohydr Polym 53:
401–408.
Kent, NL and Evers, AD (1994). Technology of Cereal: an introduction for student of food science
and agriculture. Oxford, UK, Elsevier Science.
Sollod, LM, Qiao, SW, et al. (2012). Nomenclature and listing of celiac disease relevant gluten
T-cell epitopes restricted by HLA-DQ molecules. Immunogenetics DOI 10.1007/s00251-0120599-z.
Wilson, TA, Idreis, HM, et al. (2002). Whole fat rice bran reduces the development of early
aortic atherosclerosis in hypercholesterolemic hamsters compared with wheat bran. Nutr Res
22:1319-1322.
Wolever, TMS, Tosh, SM, et al. (2010). Physiochemical properties of oat -glucan influence
its ability to reduce serum LDL cholesterol in humans: a randomised clinical trial. Am J Clin Nutr
92:723-732.
Wong, JM, de Souza, R, et al. (2006).Colonic health: fermentation and short chain fatty acids. J
Clin Gastroenterol 40:235-243.
Zadernowski, R, Nowak-Polakowska, H, et al. (1999). The influence of heat treatment on the
activity of lipo- and hydrophilic components of oat grain. J Food Process Preserv 23:177-191.
Zhou, M, Robards, K, et al. (1999). Oat Lipids. JAOCS 76:159-169.
Ren, Y, Yang, X, et al. (2011). Chemical characterization of the avenanthramide-rich extract from
oat and its effect on D-galactose-induced oxidative stress in mice. J Agric Food Chem 59:206-11.
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