Ryan Kennedy
Dietary Supplement Fact Sheet
Nutrition for Fitness
Professor Gibala, Fall 2013
Flaxseed (Linum usitatissimum)
Introduction
Flaxseed are a product of the flax plant, which is grown in abundance in cooler areas of the world such
as Canada and the Northwestern United States. Seeds come in two basic varieties: brown and yellow or
golden. With the exception of a specific yellow seed called Linola (Solin), flaxseeds are loaded with short
chain omega-3 fatty acids. Believed to have originated in Egypt, flaxseeds are often taken themselves as
a supplement or converted into flaxseed oil. Flaxseeds are very high in dietary fiber, and may help lower
cholesterol as well as assist in the treatment of breast and prostate cancers. The use of flaxseed as a
nutritional supplement dates back thousands of years.
Health Claims
-“Supports healthy brain and eye function”
-“Regulates cholesterol levels, bowel movements and relieves constipation”
-“Helps in treatments of breast and prostate cancers”
Mechanism for Action
-Flaxseed is composed of multiple chemical constituents. Studies have attributed different properties to
the flaxseeds, oils, and other individual flax plant components.
-The biological activity of flax lignans is often attributed to their conversion to the mammalian lignans
enterolactone and enterodiol. (Muir, 2006)
-Intermediate compounds generated during the metabolism of flax lignans, such as secoisolariciresinol
diglycoside (SDG) and secoisolariciresinol or (Seco) may also be some principal bioactive molecules.
(Damude and Kinney, 2007)
-Flaxseeds, oils and plant components contain polyunsaturated fatty acids, including alpha-linolenic acid
(ALA) and linolenic acid. ALA is poorly converted by the human body to eicosapentaenoic acid (EPA) and
docosahexaenoic acid (DHA) in certain populations that lack the enzymatic capacity to do this
conversion. (Damude and Kinney, 2007)
-Flaxseed also contains monounsaturated fatty acids such as oleic acid. ALA and linoleic acid are both
essential fatty acids, meaning they cannot be synthesized by the human body and must be derived from
the diet. (Faintuch et al. 2007)
Accuracy of Health Claims
-Studies of flaxseed in regards to lowering cholesterol levels report mixed results. A 2009 review of the
clinical research found that cholesterol lowering effects were more apparent in postmenopausal women
and in people with high initial cholesterol concentrations. (Pan, Yu, Denmark, 2009)
-Some studies suggest that alpha-linoleic acid may benefit people with heart disease. However, more
conclusive research is required to determine if flaxseed can be recommended as a part of an effective
treatment of any heart conditions. (Flaxseed)
-Studies are beginning to emerge suggesting that flaxseed might reduce the risk of certain cancers.
However there is not enough conclusive research to support a recommendation for cancer treatment.
(Flaxseed)
Adverse Reactions
-Flaxseed, flaxseed oil, and other components of the Flax plant used in supplementation seem to be well
tolerated in most cases, with few side effects reported. (Flaxseed)
-Flaxseed, like any supplemental fiber source, should be taken with plenty of water. Failure to do so may
result in worsening constipation or, in rare cases, even cause intestinal blockage. Both flaxseed and
flaxseed oil can cause diarrhea. (Flaxseed)
-The fiber in flaxseed may lower the body’s ability to absorb medications that are taken orally. Flaxseed
should not be taken at the same time as any conventional oral medications or other
dietary supplements. (Flaxseed)
-Physically active individuals who are pregnant, breastfeeding, have diabetes, bowel obstructions or
certain hormone-influenced cancers may want to avoid flax seed and flax seed oil supplementation.
(Flaxseed)
Recommendations for Use
-Clinical research supports physically active individuals supplementing with flax seed in attempts to
improve breakdown of dietary lipids, an ideal supplement for the endurance athlete.
-The Omega-3 fatty acids in flaxseed may improve an athlete's response time due to improved
conditioning of the brain and central nervous system.
-Flaxseed, oils, or flax plant components may help lower cholesterol and is often used as a natural
laxative, but none of which can be definitively recommended in the treatment of heart disease or any
cancers without further research
References
Damude, H. G. and Kinney, A. J. Engineering oilseed plants for a sustainable, land-based source of long
chain polyunsaturated fatty acids. Lipids 2007;42(3):179-185.
Faintuch, J., Horie, L. M., Barbeiro, H. V., Barbeiro, D. F., Soriano, F. G., Ishida, R. K., and
Cecconello, I. Systemic inflammation in morbidly obese subjects: response to oral
supplementation with alpha-linolenic acid. Obes Surg 2007;17(3):341-347
Flaxseed. Natural Medicines Comprehensive Database Web site. Accessed at
www.naturaldatabase.com on December 1st, 2013.
Muir, A. D. Flax lignans--analytical methods and how they influence our understanding of
biological activity J AOAC Int 2006;89(4):1147-1157.
Pan A, Yu D, Demark-Wahnefried W. Meta-analysis of the effects of flaxseed interventions on
blood lipids. American Journal of Clinical Nutrition. 2009;90(2):288–297.