Download Omega-3 Fatty Acids Meet the DRIs

David M. Klurfeld
Agricultural Research Service
Beltsville, MD
Disclaimers
 The views presented here are those of the speaker and
do not necessarily reflect official positions of the
USDA or the Agricultural Research Service
 I am a member of the Federal DRI Steering Committee
 U.S. – USDA, DHHS, DOD
 Canada – Health Canada, Canadian Institutes of Health
Research
Dietary Reference Intakes
 Developed in 1941, published at ~10-year intervals
 Recommended Dietary Allowances in U.S.
 Recommended Nutrient Intakes in Canada
 Series of 7 volumes published 1997-2002
 Concept broadened from preventing deficiencies to also
preventing chronic disease
 Includes upper limits of intake
 Intended to highlight concepts of probability and risk for
defining reference values
 Currently includes only essential nutrients
Dietary Reference Intakes
 Estimated Average Requirement (EAR)
 Level of intake for which the risk of inadequacy is 50%
 Recommended Dietary Allowance
 2 SD above EAR
 Adequate Intake (AI)
 Set when EAR cannot be established
 Usually due to lack of dose-response data
 Set for at least 12 nutrients
 Chronic disease endpoint used for few nutrients, all with AI

Fiber, Fluoride, Potassium, AMDRs, Sodium, Chloride
Dietary Reference Intakes
 Volume on Energy, Carbohydrate, Fiber, Fat, Fatty
Acids, Cholesterol, Protein, and Amino Acids
 1331 pages, published 2002/2005
 120 pages on Dietary Fats: Total Fat and Fatty Acids
 Linoleic acid (18:2) is the only essential n-6
 AI – 17 g/d for men; 12 g/d for women
 Alpha-Linolenic acid (18:3 n-3)
 “The AI can provide the beneficial health effects
associated with the consumption of n-3 fatty acids.”
Omega-3 Fatty Acid Recommendations
 Acceptable Intake
 0.5 g/day of n-3 for infants
 1.6 g/day of ALA for men
~0.6% En
 1.1 g/day of ALA for women
 Based on median intake of ALA in CSFII where signs of
deficiency were nonexistent
 EPA and DHA can contribute 10% to the AI for ALA
based on estimated intake
Source: Dietary References Intakes, IOM, 2002/2005
G. Danaei et al, PLoS Medicine, 6(4): e1000058 (2009)
Omega-3’s Prevent/Treat/Cure:










Heart disease
Hypertriglyceridemia
Hypertension
Fast/slow heart rate
Arrhythmia
Depression
Criminal behavior
Diabetes
Arthritis
Macular degeneration










Cancer
Clotting disorders
Inflammation
Cognitive decline
Alzheimer’s disease
Premature delivery
ADHD
Autism
Allergies
Yada, yada, yada
What Constitutes Evidence?
 “The authors should please note that in dietary
epidemiology, prospective cohort studies are regarded
virtually on a par with RCTs …. This could be better
emphasized ….”
 Epidemiologist referee on systematic review paper
 “In terms of prevention, you should discount all claims
about effects discovered in observational studies.
Consider them hypotheses to be evaluated.”
 J. Michael Oakes, U Minn, IOM Workshop, Jan 8, 2009
DRI Research Synthesis
 Workshop held at IOM June 7-8, 2006
 “It probably is important to revisit DRIs for fatty acids,
particularly for n-3 fatty acids, to consider health
promotion rather than deficiency symptoms. Also,
considerable research published since 2002
concerning docosahexaenoic acid (DHA) and
eicosapentaenoic acid (EPA) merits consideration with
regard to setting DRI values for these two fatty acids.”
 Page 76 from Workshop Summary book, 2007
Are EPA & DHA Essential?
 Conversion from ALA ranges from 1% to 10%
 Higher at low n-6/n-3 ratio of 2:1
 Typical U.S. ratio of 10:1, conversion ~1%
 Many people consume no preformed EPA or DHA
from fish/marine products
 Efficient recycling of essential fatty acids in absence of
intake
 So … there are no data demonstrating classical
nutritional deficiency
Dietary Guidelines for Americans
 2010 DGA recommend “8 ounces/week of a variety of
seafood, which provide and average consumption of 250
mg/day of EPA and DHA, associated with reduce cardiac
deaths among individuals with and without pre-existing
cardiovascular disease…The recommendation is to
consume seafood for the total package of benefits that
seafood provides, including its EPA and DHA content.”
IFIC Foundation Food & Health Survey, 2011
IFIC Foundation Food & Health Survey, 2011
IFIC Foundation Food & Health Survey, 2011
As of March 12, 2012 …
 PubMed search for “omega 3 fatty acids” or “n-3 fatty
acids”
 16,644 papers

& “human” – 6891 papers
 3,016 reviews

& “human” – 2245 papers
 & “clinical trial” – 982 papers
What’s Next for DRIs ???
 Currently evaluating positives and negatives from
process for vitamin D/calcium report (2011)
 Establishing process for prioritizing nutrients to be
reviewed
 Federal DRI Steering Committee decides
 DRIs – for prevention of deficiency or primary
prevention of a chronic disease in the general
population – secondary prevention studies not used
 Is there a biomarker that can be measured?
 Are there RCTs? Or are all the data observational?
“And a piece of algae for Omega-3.”