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Flax Seed is derived from
the flax (Linum usitatissimum) plant, an annual
herb believed to have originated in Egypt. The ancient Egyptians used flax
Seed for nutritional and medicinal purposes as well as the fiber contained in the flax plant to make clothes, fishnets, and
other products. Throughout history, Flax Seed has been primarily used as a mild laxative. It is high in fiber and a gummy
material called mucilage. These substances expand when they come in contact with water, so they add bulk to stool and help
it move more quickly through the gastrointestinal tract, thereby acting as a laxative for constipation.
The seeds and oil of the
flax plant also contain substances that promote good health. Flax Seed and flaxseed oil are rich in alpha-linolenic acid (ALA), an essential fatty acid.
ALA belongs to a group of substances
called omega-3 fatty acids. It is important to maintain an appropriate balance of omega-3 and omega-6 (another essential fatty
acid) in the diet as these two substances work together to promote health. A healthy diet should consist of roughly two to
four times more omega-6 fatty acids than omega-3 fatty acids. The typical American diet tends to contain 14 to 30 times more
omega-6 fatty acids than omega-3 fatty acids and many researchers believe this imbalance is a significant factor in the rising
rate of inflammatory disorders in the United States.
Flax Seed is by far the
richest source of alpha-linolenic acid (ALA), the parent compound of the omega-3 fatty acids. In comparison, fish contain only
trace amounts of ALA and fish oil can adversely affect the taste and odor of food products.
Omega-3 is an essential
fatty acid because it cannot be synthesized by the body. Research indicates that ALA improves immunity, the body's ability to defend itself
against foreign substances. Both the Food and Agriculture Organization and the World Health Organization recommend an increased
daily intake of omega-3 fatty acids.
In terms of potential health
benefits, it is better to consume whole Flax Seeds or Flax Seed oil. Flax Seeds are the better choice. Generally speaking,
Flax Seed oil, unlike plain flax Seed, does not contain lignans-plant estrogens. The oil also lacks soluble fiber. Moreover,
Flax Seed oil has poor stability, with an optimal shelf life-even in the refrigerator-of only six weeks. Note that in order
for the health benefits of flax Seed to be attainable, the seeds must be ground. Otherwise, they pass through the gastrointestinal
tract whole, making the healthful substances inside them unavailable to the body
Selected Scientific Studies
Cancer prevention and reduction of tumor growth
In addition to the important omega-3 fatty acid ALA as outlined, Flax Seed also
contains a group of chemicals called lignans that may play a role in the prevention of cancer. Lignans are plant compounds
that mimic the action of the hormone estrogen. For this reason, lignans are considered phyto (plant) estrogens.
Breast cancer prevention
A number of animal studies have provided evidence that Flax Seed consumption
may inhibit the development of breast cancer (1). A substantial body of responsible research suggests that plant estrogens-
Soya and Flax Seeds- reduces the risk of breast cancer. How do they do it? No one knows for sure, but researchers generally
subscribe to one consistent theory: the biochemical structure of the plant estrogens is similar to those of the estrogens
produced by the women’s body. Plant estrogens, however, are much weaker than the cancer- implicated estrogen estradiols
and estrone. Despite their weakness, plant estrogens appear to travel through the bloodstream to estrogen- receptor sites
in breast and sexual organs. When they reach these receptor sites, they seem to latch on and take up residence. While they
appear to have beneficial estrogenic effects- diminishing menopausal symptoms and positively affecting menstruation- they
do not seem to exert harmful carcinogenic effects. As long as plant estrogens reside in the estrogen- receptor sites, there
doesn’t appear to be room for the cancer- implicated estrogens and wreak havoc.
Colon Cancer
Laboratory
studies show that lignans may slow the growth of colon tumor cells, although the mechanism for this action is unclear. Flax
Seed has been shown to significantly reduce the number of abnormal cell growths—early markers of colon cancer—in
the colons of rats. Further studies are needed to determine whether Flax Seed offers such protective effects against colorectal
cancer in people (2).
Prostate Cancer
Researchers are investigating whether lignans in Flax Seed help prevent prostate cancer. In one study that compared
25 men with prostate cancer to the same number of men without the disease, researchers found that men who consumed a low-fat,
Flax Seed-supplemented diet for one month had slower tumor progression than those who did not consume the diet. Further studies
are needed to confirm these preliminary findings, however. This is particularly important because, like breast cancer, prostate
cancer is hormone-responsive. Therefore, there is some question regarding whether the phytoestrogens from the lignans in Flax
Seed may actually stimulate growth of prostate cancer. More research is needed (3-4).
Since Flax has a long anticancer folk history, it is interesting to
see that Linum contains the anticancer agents 3'-demethylpodophyllotoxin, podophyllotoxin and b-sitosterol (5).
High cholesterol
People who follow a Mediterranean diet tend to have higher HDL ("good") cholesterol levels. The Mediterranean
diet consists of a healthy balance between omega-3 and omega-6 fatty acids. It emphasizes whole grains, root and green vegetables,
daily intake of fruit, fish and poultry, olive and canola oils, and ALA (from Flax Seed, Flax Seed oil, and walnuts), along
with discouragement of ingestion of red meat and total avoidance of butter and cream.
Studies have shown that alpha-linolenic acid may lower the risk of
stroke and other cardiovascular diseases. Both the Food and Agriculture Organization and the World Health Organization recommend
an increased daily intake of omega-3 fatty acids. Flax Seed is by far the richest source of alpha-linolenic acid (ALA), the parent compound of the omega-3 fatty acids and it is not surprising that Flax Seed as well as Flax Seed oil
appears to enhance heart health.
In the British Medical Journal S. C. Cunnane described the effects
of Flax Seed on cholesterol. The diets of healthy young women (average age twenty-four) were supplemented with 50 g (about
4 table spoons) of Flax Seed flour per day. After four weeks, their total cholesterol level was lowered by 9 percent. But
more important, their LDL ("Bad cholesterol") lowered by 18 percent (6). Stephen Cunnane also noted that the omega-3 fatty
acids in Flax Seed help prevent blood clots that might lead to heart attacks (7). Bierenbaum et al. suggested that Flax Seed
supplementation in hyperlipemic individuals could have antiatherogenic effects by lowering total cholesterol, LDL cholesterol
and triglycerides (8). Others have suggested a similar antiatherogenic effect by lowering platelet aggregation (9) or by increasing
bleeding time (10). Several other studies have shown similar benefits (11-14).
Immune Booster
Flax Seed boosts the immune system in two ways. First from the plant
omega 3 fatty acids and second from the lignans. Research suggests that they both moderate the immune response and may play
a benificial role in the clinical management of "Hyper-stimulated" immune and inflammatory diseases such as rheumatoid arthritis,
psoriasis and eczema, multiple sclerosis, systematic lupus erythmatosis and ulcerative colitis (15,19).
Menstrual Pain
In a study of nearly 200 Danish women, those with the highest dietary intake of omega-3 fatty acids had the mildest
symptoms during menstruation (20).
Asthma
Preliminary
research suggests that omega-3 fatty acids (including Flax Seeds) may decrease inflammation and improve lung function in adults
with asthma (21).
Inflammatory bowel disease (IBD)
Some people with Crohn's disease (CD), one form of IBD, have low levels of omega-3 fatty acids
in their bodies. Preliminary animal studies have found that ALA (such as from Flax Seed) may
reduce bowel inflammation, but further studies in humans are needed to confirm these findings (22-23).
Precautions
The use of herbs is a time-honored
approach to strengthening the body and treating disease. Herbs, however, contain active substances that can trigger side effects
and interact with other herbs, supplements, or medications. For these reasons, herbs should be taken with care, under the
supervision of a practitioner knowledgeable in the field of botanical medicine.
Flax Seed may slow down
the absorption of oral medications or other nutrients if taken at the same time; therefore, Flax Seed should be ingested several
hours before or after other medications Talk to your health care provider before taking Flax Seed if you regularly take any
prescription or over-the-counter medications.
Possible Interactions
If you are currently being
treated with any of the following medications, you should not use flaxseed without first talking to your healthcare provider.
Blood Thinning Medications
Omega-3 fatty acids may increase the blood-thinning effects of aspirin or warfarin.
While the combination of aspirin and omega-3 fatty acids may actually be helpful under certain circumstances (such as heart
disease), they should only be taken together under the guidance and supervision of your healthcare provider.
Cholesterol Lowering
Medications, Statins
Following certain nutritional guidelines, including
increasing the amount of omega-3 fatty acids in your diet and reducing the omega-6 to omega-3 ratio, may allow a group of
cholesterol lowering medications known as "statins" (such as atorvastatin, lovastatin, and simvastatin) to work more effectively
(24).
Cyclosporine
Taking omega-3 fatty acids during
cyclosporine therapy may reduce toxic side effects (such as high blood pressure and kidney damage) associated with this medication
in transplant patients.
Nonsteroidal anti-inflammatory
drugs (NSAIDs)
In
an animal study, treatment with omega-3 fatty acids reduced the risk of ulcers from nonsteroidal anti-inflammatory drugs (NSAIDs).
More research is needed to evaluate whether omega-3 fatty acids would have the same effects in people. Other
Flaxseed may slow down the absorption of oral medications or other nutrients if taken at the
same time. Try to avoid taking flaxseed at the same time of day as medications and other supplements.
References
- Thompson LU. et.al., Flaxseed and its lignan
and oil components reduce mammary tumor growth at a late stage of carcinogenesis. Carcinogenesis 17(6), 1373-1376 (1996).
- Jenab M et.al., The influence of flaxseed
and lignans on colon carcinogenesis and Alpha-glucuronidase activity. Carcinogenesis 17(6), 1343-1348 (1996).
- Demark-Wahnefried W., et al. Pilot study of
dietary fat restriction and flaxseed supplementation in men with prostate cancer before surgery: exploring the effects on
hormonal levels, prostate-specific antigen, and histopathologic features. Urology., 58(1):47-52 (2001).
- Denis L. et.al., Diet and its preventive role
in prostatic disease. [Review]. Eur Urol., 35(5-6):377-387 (1999).
-
- Cunnane S. C., et.al., (1994) Nutritional
attributes of traditional FS in healthy young adults. Am. J. Clin. Nutr. 61, 62-68.
- Cunnane S. C., et.al., (1994) Nutritional
attributes of traditional FS in healthy young adults. Am. J. Clin. Nutr. 61, 62-68.
- Bierenbaum et.al. Reducing atherogenic risk
in hyperlipemic humans with FS supplementation 'a preliminary report'. J. Am. Coll. Nutr. 12(5), 501-504, (1993).
- Allman MA, et.al., Supplementation with FS
oil versus sunflower seed oil in healthy young men consuming a low fat diet: effects on platelet composition and function.
Eur. J. Clin. Nutr. 49, 69-178, (1995).
- Walisundera M. N., et.al., Chemical and nutritional
studies of FS (variety Linott) in rats. J. Nutr. Biochem. 3, 232-240 (1992).
- Singer P, et.al. (1990) Effects of dietary
oleic, linoleic and a-linolenic acids on blood pressure, plasma lipids, lipoproteins and the formation of eicosanoid precursors
in patients with mild hypertension. J. Hum. Hypertens. 4, 227-233.
- Prasad K, et.al., Reduction of hypercholesterolemic
atherosclerosis by CDC-flaxseed with very low ALA. Atherosclerosis 136(2), 367-375 ((1998).
- Prasad K. Reduction of serum cholesterol and
hypercholesterolemic atherosclerosis in rabbits by secoisolariciresinol diglucoside isolated from flaxseed. Circulation.,
99(10):1355-1362 (1999).
- Prasad K. Dietary flaxseed in prevention of
hypercholesterolemic atherosclerosis. Atherosclerosis., 132(1):69–76 (1997).
- Nordstrom DCE, et.al., Alpha-linolenic acid
in the treatment of rheumatoid arthritis, a double-blind, placebo-controlled and randomized study: FS vs. Safflower seed.
Rheumatol Int. 14, 231-234, (1995).
- Kremer J. M., et.al., N-3 fatty acid supplements
in rheumatoid arthritis. Am J Clin Nutr., (suppl 1):349S-351S (2000).
- Mayser P., et al., Omega-3 fatty acid-based
lipid infusion in patients with chronic plaque psoriasis: results of a double-blind, randomized, placebo controlled, multicenter
trial. J Am Acad Dermatol., 38(4):539-547 (1998).
- Clark WF, et.al., Flaxseed: a potential treatment
for lupus nephritis. Kidney Int. 48, 475 –480 (1995).
- Clark W, F., et.al. Flaxseed in lupus nephritis:
a two–year nonplacebo-controlled crossover study. J Am Coll Nutr.;20(2 Suppl):143-148 (2001).
- Deutch B. Menstrual pain in Danish women correlated
with low n-3 polyunsaturated fatty acid intake. Eur J Clin Nutr., 49(7):508-516 (1995).
- Okamoto M., et al., Effects of dietary supplementation
with n-3 fatty acids compared with n-6 fatty acids on bronchial asthma. Int Med., 39(2):107-111 (2000).
- Geerling B. J., et al., Nutritional supplementation
with N-3 fatty acids and antioxidants in patients with Crohn's disease in remission: effects on antioxidant status and fatty
acid profile. IBD., 6(2):77-84 (2000).
- Geerling B. J. et.al., Fat intake and fatty
acid profile in plasma phospholipids and adipose tissue in patients with Crohn's disease, compared with controls. Am J
Gastroenterol., 94(2):410-417 (1999).
- Hrboticky N. et.al., Alpha-Linolenic acid
reduces the lovastatin-induced rise in arachidonic acid and elevates cellular and lipoprotein eicosapentaenoic and docosahexaenoic
acid levels in Hep G2 cells. J Nutr Biochem., 7:465-471 (1996).
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