Download Dietary Analysis for the Broccoli Sprout Study 2010

Tracy Beckmann
Dietary Analysis
April 18, 2011
Dietary Analysis for the Broccoli Sprout Study 2010
The goal of this study was to examine the absorption, metabolism and activity of
sulforaphane derived from either broccoli sprouts or a purified broccoli extract supplement in
human volunteers. The cross-sectional study recruited healthy adult subjects (n=16) aged 18-60
years old. For the first phase of this study (completed in early April 2010), subjects consumed
40 g of broccoli sprouts (alfalfa sprouts for control group) then provided blood and urine samples
at 0, 3, 6, 12, 24, and 48 hours post-broccoli sprout consumption. Subjects kept dietary records
for three days (each phase) to monitor dietary intake. For one week prior to and during each
phase of the study, subjects refrained from eating vegetables containing organosulfur compounds
(including but not limited to broccoli, cabbage, onions, garlic and kale).
To compare the differences in metabolism of sulforaphane from whole food versus
supplement intake after a one-month washout period, in the same subjects, the above procedures
were repeated with a broccoli extract supplement (or placebo). For both phases of the study
metabolites in blood and urine samples and epigenetic markers in blood samples were analyzed.
This study proposes to increase knowledge of sulforaphane metabolism as well as to provide
evidence supporting dietary broccoli consumption, in whole food versus supplement form, as an
effective means of reaching physiological levels of sulforaphane which may exert anti-cancer
effects.
Dietary intake data compiled from the Broccoli Sprout Study 2010 combines information
provided from subject food records over 2 phases, each 3 days long, for 6 days total. Multivitamin and mineral intakes were included in the nutrient analyses. Food record information was
entered into The Food Processor SQL Dietary Analysis Software, 2010, Version10.6.0, available
from ESHA Research, Salem, OR.
Analysis of both subject macronutrient and micronutrient intake was evaluated (see Table
1 for specific nutrients analyzed). Between Phase 1 and 2 of the study, the difference in the
average intake of all nutrients was ≤ 12.5%. Therefore, subject dietary intake was consistent
between phase 1 and 2 of the study.
Table 1: Nutrient Intake for Broccoli Sprout Study 2010. Nutrient intakes of subjects
compared to the Recommended Dietary Allowances (RDAs) for all macronutrients and
several micronutrients.
Nutrient
Calories (kcal)
Protein (g)
Carbohydrates (g)
Fat (g)
Phase 1
Mean
Intake
2214
86
302
76
Phase 1
Percent
of RDA
84%
141%
83%
92%
Phase 2
Mean
Intake
2304
90
321
72
Phase 2
Percent
of RDA
88%
148%
89%
89%
Vitamins
Vitamin A (RAE)
Vitamin B1 (mg)
Vitamin B2 (mg)
Vitamin B3 (mg)
Vitamin B6 (mg)
Vitamin B12 (mcg)
Vitamin C (mg)
Vitamin D (IU)
Vitamin E (mg)
Folate, DFE (mcg)
864
2
2
25
2
5
168
384
13
725
114%
180%
193%
165%
157%
210%
205%
64%
87%
173%
774
2
2
25
2
6
147
420
13
639
102%
169%
194%
170%
170%
264%
183%
70%
87%
152%
Minerals
Calcium (mg)
Iron (mg)
Potassium (mg)
Sodium (mg)
Average caloric intake
consumed during Phase 1 and
Phase 2 of the study was 84%
and 88%, respectively, of the
Recommended Dietary
Allowances (RDAs) as
calculated by The Food
Processor software, which
takes into account age, gender
and activity level. A similar
pattern was observed for fat
and carbohydrate intake. Fat
intake was 92% for Phase 1
and 89% for Phase 2 of the
RDA. Carbohydrate intake
was 83% for Phase 1 and 89%
for Phase 2 of the RDA.
Accuracy of food
records is affected by the
subject’s aptitude to
accurately record the portion
size consumed and the
tendency to underreport the actual amount of food consumed (1). An individual may also alter
the amount of food consumed as a result of the food recording process (1). In addition to the
inaccuracy of food records, further error is introduced into the dietary analysis by limitations of
the nutrient analysis programs/databases. Some food products are not found in the database;
therefore, closely matched, but not exact, products are used in analysis. Also, many products in
the database have limited or incomplete data, especially for micronutrients. Despite the above
mentioned limitations, food records are a cost effective method and provide detailed daily food
and nutrient intake data, including food preparation method and snack and meal timing (1).
1040
24
2183
3321
103%
198%
46%
169%
1178
26
2390
3164
117%
218%
51%
159%
Several other factors may also have affected food record data. One subject was on a
weight loss diet and consumed approximately 61% of recommended caloric intake. However, the
same diet plan was followed for both phases of the study. Two subjects had highly variable food
consumption with caloric intake differing by 700-1300 kcals from one day to the next. This
variability may indicate inconsistent recording. In addition, there was incomplete vitamin and
mineral supplementation information for several of the subjects in this study.
The study criteria included restriction of cruciferous vegetables for one week prior to and
during each phase of the study. One subject did not refrain from cruciferous vegetable intake for
the week prior to Phase 1 and a second subject consumed an order of onion rings during Phase 2
Day 1 dinner.
Average protein intake was higher than the RDA with amounts of 141% for Phase 1 and
148% for Phase 2. These results are consistent with current literature on the average amount of
protein consumed by Americans, which states intake at 86 g, or 141% (2). Subject intake of
protein between the two phases of this study maintained <5% difference.
Most micronutrients were consumed at the recommended amounts or higher except for
vitamins E, D and potassium. For micronutrients that were consumed in amounts exceeding
100% of the RDA (including vitamins A, B1, B2, B3, B6, B12, C, folate, calcium, iron and
sodium), the levels consumed were well below the Upper Limit (UL) for those nutrients.
The average intake of vitamin E for both phases was 13 mg, or 87% the RDA for
potassium. In the US, average vitamin E intake is 50% or less (8 mg/d for men, 6 mg/d for
women) of the RDA (15 mg) (3). Subjects in our study consumed more vitamin E than the
average American. Overall, reported vitamin E consumption may be underestimated due in part
to unknown vitamin E levels of cooking and other oils consumed (4).
The mean vitamin D intake from foods alone among subjects was 64% of RDA for Phase
1 and 70% of RDA for Phase 2. The recommended amount for vitamin D was increased in 2010
to 600 IU per day for all adults aged 18-60 years old (5). The National Institutes of Health
estimate the average intake of vitamin D by Americans to be 34%-48% of RDA per day for
males and 24%-46% of RDA per day for females (6). Subjects in this study consumed more
vitamin D than the average American. Although vitamin D is found naturally in relatively few
foods, it is widely available in fortified foods (especially dairy) and in supplement form (6).
Additionally, vitamin D is converted to its active form in the human body via exposure to
ultraviolet light (5).
Potassium intake was at 46% and 51% of recommended for Phase 1 and 2, respectively.
Western diets are typically lower in potassium than the RDA, thought to be due to the high
sodium content of such diets (the processing of foods generally increases sodium levels and
decreases potassium levels) (8). Inadequate potassium intake is relatively common as the RDA is
set at a level for prevention of chronic disease, so even though the RDA is not being met
deficiency is unlikely. The modern Western diet, which consists of many processed foods and
lacking in whole grains, fresh fruits and vegetables, is therefore high in sodium and low in
potassium and may be a factor in several chronic diseases (7).
Analysis of dietary intake for the Broccoli Sprout Study 2010 found that subject intake of
nutrients was consistent and caloric contents similar during both phases of the study. All subjects
met their RDAs for age and gender with the exception of vitamins E, D and potassium, which
were consumed in lower amounts. Minimal to no sulforaphane foods were consumed during the
two study periods. Analysis of subject food records indicates that subjects were nourished and
adhered to the dietary recommendations of the study, and may offer insight to any confounding
results of sulforaphane absorption, metabolism and activity.
References:
1. Mahan, L. K., and Escott-Stump, S. (2008.) Chapter 14: Assessment: Dietary and Clinical
Data. Krause’s Food and Nutrition Therapy, 12th Edition, pp. 395-399. Missouri: Saunders,
Elsevier.
2. National Center for Health Statistics (NCHS). (2010.) Adult’s Protein Intake Much More Than
Recommended. Retrieved from http://nchspressroom.wordpress.com/category/nhanes/ on
3/23/11.
3. Linus Pauling Institute. (2007). Oregon State University. Micronutrient Information Center:
Vitamin E. Retrieved from http://lpi.oregonstate.edu/infocenter/vitamins/vitaminE/ on 3/26/11.
4. Office of Dietary Supplements.(n.d.). National Institutes of Health. Dietary Supplement Fact
Sheet: Vitamin E. Retrieved from http://ods.od.nih.gov/factsheets/vitamine/. Accessed on
11/15/10.
5. Linus Pauling Institute. (2010). Oregon State University. Micronutrient Information Center:
Vitamin D. Retrieved from http://lpi.oregonstate.edu/infocenter/vitamins/vitaminD/index.html on
3/26/11.
6. Office of Dietary Supplements.(n.d.). National Institutes of Health. Dietary Supplement Fact
Sheet: Vitamin D. Retrieved from http://ods.od.nih.gov/factsheets/vitamind/ . Accessed on
3/25/11.
7. Linus Pauling Institute. (201). Oregon State University. Micronutrient Information Center:
Potassium. Retrieved from http://lpi.oregonstate.edu/infocenter/minerals/potassium/ on 3/26/11.
8. Thompson, J.L., Manore, M. M., and Vaughan, L.A. (2008.) Chapter 9: Nutrients Involved in
Fluid and Electrolyte Balance. The Science of Nutrition, 1st Edition (pp 370-371). San
Francisco, CA: Pearson/Benjamin Cummings.