Omega-3 From Fish and Flax: A new superfood solution?
By J.H. Maher DC DCCN
Features Nutrition Wellness“Both omega-3 and omega-6
fatty acids are essential… omega-6 are significantly more
inflammatory… This necessitates that omega-3 and omega-6 be consumed
in a balanced proportion; the ideal ratio of omega-6:omega-3 being from
3:1.
“Both omega-3 and omega-6
fatty acids are essential… omega-6 are significantly more
inflammatory… This necessitates that omega-3 and omega-6 be consumed
in a balanced proportion; the ideal ratio of omega-6:omega-3 being from
3:1. Typical Western diets provide ratios of between 10:1 and 30:1 –
i.e., dramatically skewed toward omega-6.” – Simopoulos AP, Cleland LG
(eds): “omega-6/omega-3 Essential Fatty Acid Ratio: The Scientific
Evidence.” World Rev Nutr Diet. Basel, Karger, 2003, Vol 92.
Anyone who stays abreast of nutritional science knows that perhaps the
topic of greatest discussion currently is the need for more omega-3
fatty acids in the diets of most North Americans. The question is, “How
is this best accomplished?” While there is, of course, no “magic
bullet” single answer, there are new breakthroughs in functional foods
and dietary supplements that can be part of the solution.
WHAT ARE THE MAJOR OMEGA-3 FATS?
Alpha-linolenic acid (ALA) is a plant source of short chain omega-3
essential fatty acid (EFA). The all-important long chain omega-3 fats
are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA is
not technically “essential” because our bodies make EPA from ALA,
though it widely rates.1 However, DHA conversion from ALA is so poor in
many persons that some authorities think it should be classified as
“conditionally essential.”2 Alpha-linolenic acid is found mainly in
flax seeds, walnuts and in plant oils like flax, canola and soybean
oils. Flax seeds and flax oil are the richest sources of ALA in the
North American diet.3 EPA and DHA are found mainly in fatty fish like
herring, salmon, mackerel and bluefin tuna and the fish oil supplements
made from them. Marine algae, the bases of the oceanic food chain, are
rich sources of DHA, but contain little EPA.
At the present time, there is no Recommended Dietary Allowance (RDA)
for EFAs in the U.S. However, the National Academy of Sciences’
Institute of Medicine (IOM) recommends 1.6g/day of ALA for men and
1.1g/day for women.4 The American Heart Association (AHA) and the Heart
and Stroke Foundation in Canada recommend that fatty fish be consumed
twice a week.5
THE IMPORTANCE OF THE OMEGA 6-3 RATIO
Omega-6 fatty acids, specifically linoleic acid (LA) and arachidonic
acid (AA), are also essential. However, in many ways they act opposite
to the anti-inflammatory and “blood thinning” actions of the omega-3
fatty acids. Specifically, they tend to promote inflammation and
clotting. They also compete with enzymes that help short chain ALA be
converted to long chain EPA and DHA.6,7 Therefore, the consensus
recommendation is to eat more “anti-inflammatory” omega-3 fats and
fewer pro-inflammatory omega-6 fats and saturated fats.8
DO ALL OMEGA-3 FATS HAVE THE SAME HEALTH BENEFITS?
Omega-3 fats are alike in some ways and different in others.
Alpha-linolenic acid, EPA and DHA all act in support of keeping cell
membranes flexible and elastic, and block the actions of some compounds
that cause inflammation and clotting.9 Chronic diseases like heart
disease, diabetes, cancer and arthritis are marked by inflammation.
Therefore, all omega-3 fats help reduce chronic disease risk by
blocking inflammation.10,11
Still, it is generally recognized that the long chain omega-3 EPA/DHA
intake is more powerful in relation to cardiovascular disease and
inflammatory joint disease.12,13,14 Even more important to appreciate
are DHA’s unique health effects. Because it helps the eye, brain and
nervous systems develop properly, infants have a special need for DHA.
15,16,17,18,19 Aging adults may need DHA, too, as it grants the most
protection against Alzheimer’s disease.20
| Freshness and taste, no longer a problem
The greatest difficulty with omega-3 in foods is that, being 1) using only fully mature flaxseeds carefully selected and processed All together these steps result in products with longer shelf lives free of any hint of fishy taste or smell! |
A FISH STORY
Multiple clinical studies have shown the oils of fatty fish, EPA and
DHA, to be of benefit to the cardiovascular system, brain and visual
function, immune function, skin health, inflammatory modulation and
joint health.21,22 As ALA conversion to EPA is moderate at best,
depending on many variables, and conversion to DHA is minimal, it is
generally thought that regular, twice-weekly fatty fish oil
consumption, or fish oil supplementation, are the best ways to enhance
EPA/DHA status.23,24
However, the AHA warns that “some species of fish may contain
significant levels of methylmercury, polychlorinated biphenyls (PCBs),
dioxins, and other environmental contaminants. These substances are
present at low levels in fresh waters and oceans, … generally highest
in older, larger, predatory fish and marine mammals.”25 The U.S.
Environmental Protection Agency actually posts an advisory of fish
consumption!26 Both the U.S. and Canada advise pregnant and nursing
women, women who may become pregnant and young children to avoid eating
certain fish.27,28
Fish oil capsules are the most concentrated form of omega-3 fats.
Fortunately, few contain mercury. However, some may contain
carcinogenic polychlorinated biphenyls (PCBs). Consumers who follow the
label recommendation on some fish oil supplements can take in up to 43
per cent of the daily upper limit of PCBs!29
The biggest problem with deterioration in the quality of fish oil is
rancidity from oxidation. Analytical assessments of oxidation are
provided in terms of Peroxide Value (PV), Anisidine Value (AV), and
Totox Value. However, the easiest test is the “taste test.” If the oil
tastes or smells bad, it probably is bad, regardless of what the tests
say.30 Because of the lipid peroxidation, it is generally recommended
to take physiological doses of vitamin E when supplementing with fish
oils.31,32
According to AHA guidelines, supplementing more than two grams of fish
a day should be under a health professional’s guidance as it may lead
to too much blood thinning and subsequent internal bleeding.33
We should not forget that fish is the major dietary source of vitamin D
and yet is absent from most fish oils. As recent studies suggest that
consuming more Vitamin D may lower the risk of death from any common
disease of aging, especially colon and breast cancer, this is not an
unimportant omission.34,35 Those fish oils, like cod liver oil, may
have some vitamin D but may also have concomitantly high doses of
vitamin A which may be contraindicated.36
Swallowing large or numerous fish oil pills and taste, texture and
swallowing issues with fish oils, both including fishy aftertaste and
“fish burps”, can be a compliance hurdle.
FACTORS IN FAVOUR OF FLAX
Flaxseed is much more than just the richest source of ALA. Flaxseed is
approximately 38 per cent oil, which is comprised mainly of
alpha-linolenic acid, with lesser amounts of the omega-6 and omega-9
fatty acids.
Not to be overlooked, is that flaxseed’s dietary fibre content of about
28 per cent grants added health benefits. The American Dietetic
Association has cited fibre’s “significant impact” on obesity,
cardiovascular disease and Type 2 diabetes prevention and management.37
Flax has a ratio of soluble-to-insoluble fibre that can vary in a ratio
of between one part to four parts soluble-to-insoluble and four parts
to six parts, respectively.38 Insoluble dietary fibre supports healthy
elimination and colon health, and may even have protective effects
against colon cancer.39 The soluble dietary fibrefraction of flax is
found primarily as mucilage gums, which have been shown to play a role
in lowering serum cholesterol levels and glycemic control.40
Flax’s other very beneficial compound is its lignans and fibre. Lignans
are a subclass of polyphenols known as phytoestrogens – plant compounds
that can have estrogen-like actions.41 Through the actions of the
lignans and ALA, flax may block tumour growth in animals and may help
reduce breast, prostate and colon cancer risk in humans, likely by
competing with toxic endogenous and xenogenous estrogens.42,43,44,45,46
Flax consumption has been shown to lower blood cholesterol and
C-reactive protein (CRP) levels – an inflammatory marker – help reduce
the risk of heart attacks and stroke, lower death rates for all causes
of morbidity in cardiovascular disease patients, promote normal cardiac
rhythm, and inhibit atherosclerosis.47,48,49,50,51,52,53,54 Flax has
even been associated with overall longevity. Alpha-linolenic acid may
be especially important to vegans, vegetarians and people with low
intakes of fatty fish. In those who ate little or no seafood, each
1-g/day increase in dietary ALA intake was associated with a 47 per
cent reduction in the risk of coronary heart disease!55,56
It is apparent even from this briefest of introductory statements that
the immune and cardio-protective benefits of a flaxseed-rich diet come
from numerous salubrious mechanisms.
VEGAN DHA
Docosahexanoic (DHA), produced by marine micro-algae, is the vegetarian
source of almost all of DHA in the bodies of sea creatures. DHA is the
only omega-3 shown to provide brain, eye and heart health benefits in
humans. Indeed, DHA is essential for the growth and function of the
retina and brain of all humans, especially infants. (Human breast milk
is rich in DHA.) The shorter chain n-3 fatty acid, alpha-linolenic acid
(ALA), is not converted very well to the long chain DHA in humans. It
should also be noted that the turnover of DHA in the brain is very
fast, making regular intake vital.57
DHA deficiencies are associated with fetal alcohol syndrome, attention
deficit hyperactivity disorder (ADHD), cystic fibrosis, unipolar
depression, aggressive hostility, Type 2 diabetes, cognitive decline
during aging, Alzheimer’s disease and CVD.58
Increased DHA intake has a positive effect on diseases such as
hypertension, arthritis, atherosclerosis, depression, adult-onset
diabetes mellitus, myocardial infarction, thrombosis, and some cancers.
DHA oil can reduce triglycerides, thrombosis and cardiac arrhythmias.59
Today, vegan DHA oil derived straight from marine micro-algae with
excellent sensory characteristics can be harvested and extracted, under
controlled conditions that are environmentally sustainable as relates
to our overfished oceans – by avoiding killing large numbers of tuna,
and other fishes – and eliminates the risk of oceanic contamination
with compounds such as PCBs and dioxins. Today, along with flax, marine
algae-derived DHA is being used more and more to fortify breads,
cereals, juices, eggs, dairy products and functional foods.
DESIGNER FUNCTIONAL FOOD:A SUPERFOOD SOLUTION?
In view of the widespread reluctance of the public to consume
sufficient amounts of fish, and to a lesser extent fish oil
supplements, functional foods containing flax, EPA and/or DHA are
becoming increasingly important sources of these nutrients that support
optimal brain/visual performance, cardiovascular function, joint and
skin health for young and old alike. While milled flaxseed provides
many whole food benefits, its conversion to DHA is just too poor for
flax to be considered the total answer for omega-3 supplementation. But
new technologies now allow DHA from marine micro-algae to be blended into crushed flaxseeds. Using nitrogen flush
technologies in both blending and packaging allow the natural
antioxidants in the flax to preserve the freshness of the vegan-sourced
DHA. This results in the potential for the manufacture of new kinds of
complete, great tasting omega-3 functional foods and supplements.
Presuming such good taste, texture and ease of mixing, an interesting
functional food supplement would be a combination of stabilized
flaxseed, marine DHA from micro-algae, with synergistic vitamins D3, E,
and some heart-healthy B complex. The natural rich antioxidants in the
flax, like vitamin E (gamma tocopherol) and lignans, stabilize the long
chain EPA/DHA. Functional food bars, candies, “ready-to-drink” products
and powdered drink mixes, combining ALA-rich flax with vegetarian DHA,
and perhaps even synergistic vitamins, are just now coming to market.
Together with an effort to lower the intake of omega-6 fats from
linoleic acid (LA)-rich vegetable oils (corn, safflower, sunflower),
arachidonic acid (AA)-rich full-fat dairy and grain-fed animal fats,
and “bad fats” like trans fats and rancid deep-fried fats, and with
moderation in alcohol, these new “superfoods” may be part of the
solution to returning our omega-3/omega-6 dietary ratios closer to
those of our ancestors in a scientifically efficacious, highly
compliant, vegetarian, safe and environmentally sustainable way.
References:
1. In one study, for instance, the blood level of EPA increased 60% when 56 African-American adults with chronic illness consumed 3 grams of ALA daily for 12 weeks. The source of ALA in this study was flax oil capsules. Harper CR, Edwards MJ, DeFilipis AP, Jacobson TA. Flaxseed oil increases the plasma concentrations of cardioprotective (n-3) fatty acids in humans. J Nutr 2006;136:83-87.
2. DHA-EPA Omega-3 Institute. http://dhaomega3.org/index.php?category=overview&title=Conversion-of-ALA-to-DHA
3. Health Canada. Novel food information on: Omega-3 enhanced pork and products derived therefrom. Available at www.hc-sc.gc.ca/fn-an/gmf-agm/appro/dd109_v3_e.html.
4. Anon. Dietary Reference Intakes for Energy, Carbohydrates, Fiber, Fat, Protein and Amino Acids (Macronutrients). 2002. National Academy of Sciences, Institute of Medicine, Health and Human Service’s Office of Disease Prevention and Health Promotion (U.S.).
5. American Heart Association: http://www.americanheart.org/presenter.jhtml?identifier=4632, Heart and Stroke Foundation, http://www.heartandstroke.com/site/c.ikIQLcMWJtE/b.3484315/
6. Sept. 10 issue of Archives of Internal Medicine (2007;167(16):1730-37).
7. Kris-Etherton PM, Harris WS, Appel LJ. Fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease. Circulation. 2002;106(21):2747-2757.
8. Janice K. Kiecolt-Glaser , PhD, Martha A. Belury, PhD, Kyle Porter, MAS, David Q. Beversdorf , MD, Stanley Lemeshow, PhD, Ronald Glaser, PhD. Depressive Symptoms, omega-6:omega-3 Fatty Acids, and Inflammation in Older Adults. Psychosom Med 2007, doi:10.1097/PSY.0b013e3180313a45 http://www.psychosomaticmedicine.org/cgi/content/abstract/PSY.0b013e3180313a45v1
9. Caughey GE, Mantzioris E, Gibson RA, et al. The effect on human tumor necrosis factor and interleukin 1 production of diets enriched in n-3 fatty acids from vegetable oil or fish oil. Am J Clin Nutr 1996;63:116-122.
10. Zhao G, Etherton TD, Martin KR, et al. Dietary linolenic acid reduces inflammatory and lipid cardiovascular risk factors in hypercholesterolemic men and women. J Nutr 2004;134:2991-2997.
11. Lopez-Garcia E, Schulze MB, Manson JAE, et al. Consumption of (n-3) fatty acids is related to plasma biomarkers of inflammation and endothelial activation in women. British Journal of Nutrition. 97(6):1196-1205, June 2007.
12. Kris-Etherton, PM, et al. Omega-3 fatty acids and cardiovascular disease: New recommendations from the American Heart Association. Arterioscler. Thromb. Vasc. Biol. 23: 151-152, 2003.
13. van der Tempel H, Tulleken JE, Limburg PC, et al. Effects of fish oil supplementation in rheumatoid arthritis. Ann Rheum Dis 1990;49:76-80.
14. Lau CS, Morley KD, Belch JJ. Effects of fish oil supplementation on non-steroidal anti-inflammatory drug requirement in patients with mild rheumatoid arthritis – a double-blind, placebo-controlled study. Br J Rheumatol 1993;32:982-9.
15. Malcolm, CA, et al; Scotopic Electroretinogram in Term Infants Born of Mothers Supplemented with Docosahexaenoic Acid during Pregnancy. Investigative Ophthalmology and Visual Science. 2003;44:3685-3691.
16. Susan Carlson, PhD, Overview of dha in maternal and infant/child nutrition, Midwest Dairy Council Professor of Nutrition, Departments of Dietetics and Nutrition and Pediatrics University of Kansas Medical Center: http://www.ot.kumc.edu/jradel/workshops/ClinNutr_DHA_2005/01_Carlson_talk.pdf
17. Please note that supplementing the newborn with EPA displaces arachidonic acid, interfering with growth, so only DHA, not direct EPA supplementation, is used in infant formulas.
18. Simmer K, Patole S. Longchain polyunsaturated fatty acid supplementation in preterm infants. Cochrane Database Syst Rev. 2004(1):CD000375. (PubMed)
19. Uauy R, Hoffman DR, Mena P, Llanos A, Birch EE. Term infant studies of DHA and ARA supplementation on neurodevelopment: results of randomized controlled trials. J Pediatr. 2003;143(4 Suppl):S17-25. (PubMed)
20. Morris MC, Evans DA, Bienias JL, et al. Consumption of fish and n-3 fatty acids and risk of incident Alzheimer disease. Arch Neurol 2003;60:940-946.
21. Kris-Etherton PM, Harris WS, Appel LJ, for the Nutrition Committee. Fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease. Circulation 2002;106:
22. For a complete list of references related to clinical trials of EPA/DHA see http://www.truthaboutomega3.com/benefit.html?pg=g01-001-1000D&abc=4&gid=118798605113011
23. It has been suggested that only about 15 per cent of ALA converts to EPA and five per cent to DHA. (H. Gerster. Conversion of ALA and DHA. Internat. J Vit. Nutr. Res 68 (1998)-Cunnane, 1995, Nutrition Advisory Panel, 1995).
24. Conversion inhibition factors include high omega-6 diet, high alcohol, deficiency of vitamins B3, B6, and CD, and minerals zinc and magnesium, aging, and genetics.
25. Kris-Etherton PM, PhD, RD; William S. Harris, PhD; Lawrence J. Appel, MD, MPH, Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease, AHA Scientific Statement, Circulation. 2002; 106:2747.
26. Fish Advisories: http://www.epa.gov/waterscience/fish/
27. Health Canada. Advisory: Information on mercury levels in fish (May 2002). Available at www.hc-sc.gc.ca.
28. Food and Drug Administration. What you need to know about mercury in fish and shellfish (March 2004). Available at www.cfsan.fda.gov.
29. Shim SM, Santerre CR, Burgess JR, Deardorff DC. Omega-3 fatty acids and total polychlorinated biphenyls in 26 dietary supplements. J Food Sci 2003;68:2436-2440.
30. Rancidity vs. Purity of Fish Oil: http://www.marine-ingredients.com/research/rancidity_vs_purity_of_fo.pdf
31. Allard JP, Kurian R, Aghdassi E, Muggli R, et al. Lipid peroxidation during n-3 fatty acid and vitamin E supplementation in humans. Lipids 1997;32:535-41.
32. Cho SH, Im JG, Choi YS, Son YS, Chung MH. Lipid peroxidation and 8-hydroxydeoxyguanosine formation in rats fed fish oil with different levels of vitamin E, J Nutr Sci Vitaminol (Tokyo). 1995 Feb;41(1):61-72.
33. Therapeutic dosages of over 3 gm a day (900 mg EPA/DHA), as may be recommended in heart disease or R.A, may increase a tendency to hemorrhage and interfere with immune function. The AHA therefore recommends physician guidance at such levels.
Penny M. Kris-Etherton, PhD, RD; William S. Harris, PhD; Lawrence J. Appel, MD, MPH, Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease, AHA Scientific Statement, Circulation. 2002;106:2747.)
34. Archives of Internal Medicine, Sept. 10, 2007;167(16):1730-37:
http://www.naturalproductsmarketplace.com/hotnews/7ah23113053.html
35. Garland, Cedric F. et al. "What is the dose-response relationship between vitamin D and cancer risk?" Nutrition Reviews 65;8 (Suppl):91-95.
36. Dietary Supplement Fact Sheet: Vitamin A and Carotenoids, Office of Dietary Supplements, National Institutes of Health.
http://dietary-supplements.info.nih.gov/factsheets/vitamina.asp
37. American Dietetic Association. 1997. Health implications of dietary fiber – Position of American Dietetic Association. J. Am. Diet. Assoc. 971157-1159.
38. Hadley, M, Lacher, C,Mitchell-Fetch, J. 1992. Fiber in Flaxseed. Proc. Flax Inst. 54:79-83.
39. Ibid. 24
40. Wendy J. Dahl, Erin A. Lockert, Allison L. Cammer, Susan J. Whiting. Effects of Flax Fiber on Laxation and Glycemic Response in Healthy Volunteers, Journal of Medicinal Food. 2005, 8(4): 508-511.
41. Flax Council of Canada. Flax—A Health and Nutrition Primer. Winnipeg, MB, 2003. www.flaxcouncil.ca.
42. Joanne L. Slavin, PhD, RD, Mechanisms for the Impact of Whole Grain Foods on Cancer Risk, Journal of the American College of Nutrition, Vol. 19, No. 90003, 300S-307S (2000).
43. Joanne L. Slavin, PhD, RD, Mechanisms for the Impact of Whole Grain Foods on Cancer Risk, Journal of the American College of Nutrition, Vol. 19, No. 90003, 300S-307S (2000).
44. The major lignan in flax is secoisolariciresinol D glucoside (SDG). SDG also has anti-viral, anti-bacterial, anti-fungal and immune enhancing properties and is a potent antioxidant, 500 per cent more powerful than vitamin E. Prasad, K. "Antioxidant Activity of Secoisolariciresinol D diglycoside derived Metabolites, Secoisolariciresinol, Enterodiol, and Enterolactone" Int. Journal of Angiology, 2000 Oct. 9(4): 220-225
45. David Ingram, Katherine Sanders, Marlene Kolybaba, Derrick Lopez.Case Control Study of Phyto-oestrogens and Reduction in breast-cancer risk, University Department of Surgery, Queen Elizabeth II Medical Centre, Perth, Western Australia, http://www.blossom-s.com/phytoe.cc.pdf
46. Baillieres Clin Endocrinol Metab. 1998 Dec;12(4):625-47. Phytoestrogens and diseases of the prostate gland. Griffiths K, Denis L, Turkes A, Morton MS. Tenovus Cancer Research Centre, University of Wales College of Medicine, Cardiff, UK.
47. Mozaffarian D, Ascherio A, Hu FB, et al. Interplay between different polyunsaturated fatty acids and risk of coronary heart disease in men. Circulation 2005;111:157-164.
48. Paschos GK, Magkos F, Panagiotakos DB, Votteas V, and Zampelas A, Dietary supplementation with flaxseed oil lowers blood pressure in dyslipidaemic patients. European Journal of Clinical Nutrition (2007) 61, 1201–1206.
49. Goyens P L L and Mensink R P, Effects of alpha-linolenic acid versus those of EPA/DHA on cardiovascular risk markers in healthy elderly subjects. European Journal of Clinical Nutrition (2006) 60, 978–984.
50. Ascherio, A., Rimm, E.B., Giovannucci, E.L., et al. 1996. Dietary fat and risk of coronary heart disease in men: Cohort follow-up study in the United States. Br. Med. J. 313:84-90.
51. Renaud, S., de Lorgeril, M., Delaye, J. et al. 1995. Cretan Mediterranean diet for prevention of coronary heart disease. Am. .J Clin.Nutr. 61(Suppl):1360S-7S.
52. http://www.americanheart.org/presenter.jhtml?identifier=4655
53. Cunnane, SC, et al. 1995. Nutritional attributes of traditional flaxseed in healthy young adults. Am. J. Clin.Nutr. 61(1):62-68.
54. Lopez-Garcia, E, Schulze, MB, Manson, JE, et al. 2004. Consumption of n3 fatty acids is related to plasma biomarkers of inflammation and endothelial activation in women. J. Nutr. 134:1806-1811.
55. Mozaffarian D. Does alpha-linolenic acid intake reduce the risk of coronary heart disease? A review of the evidence.. Alt Ther 2005;11:24-30.
56. Hu FB, Stampfer MJ, Manson JE, et al. Dietary intake of alpha-linolenic acid and risk of fatal ischemic heart disease among women. Am J Clin Nutr. 1999;69(5):890-897. (PubMed)
57. Horrocks LA, Yeo YK. Health Benefits of DHA, Pharmacol Res. 1999 Sep;40(3):211-25.
58. Ibid. 57
59. Ibid 58
Dr. J.H. Maher oversees both physician and consumer education for
BioPharma Scientific. He maintained an active chiropractic practice for
25 years, and has taught nutrition to health professionals for the past
15 years. A past post-graduate faculty member of New York Chiropractic
College’s Academy of Anti-Aging Medicine, Dr. Maher is also a diplomate
of the College of Clinical Nutrition, and a fellow of the American
Academy of Integrative Medicine.
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