Flaxseed or linseed ( Linum usitatissimum L.) is derived from the flax plant, an annual herb believed to have originated in Egypt. The ancient Egyptians used flaxseed for nutritional and medicinal purposes. They also used the fiber contained in the flax plant to make clothes, fishnets, and other products. Throughout history, flaxseed has been primarily used as a 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. Flaxseed and flaxseed oil are rich in alpha-linolenic acid (ALA), an essential fatty acid that appears to be beneficial for heart disease, inflammatory bowel disease, arthritis, and a variety of other health problems. Other plants that provide ALA include canola (rapeseed), soybean oil, walnuts, and pumpkin seed.

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. Mackerel, salmon, and walnuts are also good sources of omega-3 fatty acids. Most omega-6 fatty acids tend to promote inflammation while omega-3 fatty acids help reduce inflammation. A healthy diet should consist of roughly 2 - 4 times more omega-6 fatty acids than omega-3 fatty acids. The typical American diet tends to contain 14 - 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, including heart disease, cancer, and arthritis. Other omega-3 fatty acids include those found in fish oil (docosahexaenoic acid or DHA, and eicosapentaenoic acid or EPA).

ALA can be converted to long-chain omega-3 fatty acids (DHA and EPA) and can therefore be substituted for fish oils. However, EPA and DHA (the fish oils) are more rapidly incorporated into plasma and membrane lipids and produce more rapid effects than does ALA. Only a small amount of ALA is converted to DHA or EPA in the body, so larger quantities of flaxseed oil need to be taken to get the same effects from fish oils. Larger quantities of flaxseed oil may increase the chances of diarrhea and may increase blood sugar levels. One advantage of the consumption of ALA over omega-3 fats from fish is that the problem of insufficient vitamin E intake does not exist with high intake of ALA from plant sources. Generally, if an individual wishes to supplement the diet with an omega-3 fatty acid, fish oil products would be preferred to flaxseed oil.

Studies suggest that flaxseed (both the ALA in the flaxseed oil and the lignans in the seed) may play a role in the prevention and treatment of the following health conditions:

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, omega-6, and omega-9 (found in olive oil) fatty acids. It emphasizes whole grains, root and green vegetables, daily intake of fruit, fish and poultry, olive and canola oils, and ALA (from flaxseed, flaxseed oil, and walnuts), along with discouragement of ingestion of red meat and not much use of butter and cream.

Flaxseed and flaxseed oil have been reported to possess cholesterol-lowering properties in laboratory studies. Human studies have used flaxseed products and measured effects on cholesterol, with mixed results. A human study found that dietary flaxseed significantly improved lipid (cholesterol) profile in patients with high cholesterol, and may favorably modify cardiovascular risk factors.

Heart disease

A diet rich in fruits, vegetables, whole grains, nuts or legumes, and ALA-rich foods may substantially reduce the recurrence of heart disease. One of the best ways to help prevent and treat heart disease is to eat a low-fat diet and to replace foods rich in saturated and trans-fat with those that are rich in monounsaturated and polyunsaturated fats (including omega-3 fatty acids from flaxseed). Evidence suggests that people who eat an ALA-rich diet are less likely to suffer a fatal heart attack.

• ALA may reduce heart disease risks through a variety of biological mechanisms, including platelet function (making them less "sticky"), inflammation, blood vessel health, and arrhythmia (irregular heart beat).
• Several human studies also suggest that diets rich in omega-3 fatty acids (including ALA) may lower blood pressure.

Menopausal symptoms

Flaxseed was compared to hormone replacement therapy (HRT) in menopausal women. 40 g of flaxseed was reported to be equally effective as HRT for mild menopausal symptoms (hot flashes, mood disturbances, vaginal dryness) and to lower blood sugar levels. However, a few studies report no benefits in reducing menopausal symptoms when using flaxseed oil. Flaxseed was also found to be beneficial in bone health, potentially decreasing the chances of developing osteoporosis.

Lignans from flaxseed

In addition to the important omega-3 fatty acid ALA, flaxseed (not the oil) also contains a group of chemicals called lignans that may protect the body from cancer. Lignans are plant compounds that mimic the action of the natural hormone estrogen. For this reason, lignans are considered phyto (plant) estrogens. Because of their estrogen-like activity, scientists aren't sure whether flaxseed would be harmful or helpful for breast cancer. Several laboratory studies support the use of flaxseed oil in preventing cancer development.

Laboratory studies have reported reduction in breast tumor growth and metastasis (spreading) in rats. A human study has examined the effects of dietary flaxseed in postmenopausal patients with newly diagnosed breast cancer. The authors found that dietary flaxseed may have the potential to reduce tumor growth in patients with breast cancer.

Colon cancer

Laboratory studies show that lignans may slow the growth of colon tumor cells and some studies have found that flaxseed may significantly reduce the number of abnormal cell growths (early markers of colon cancer). More research is needed.

Prostate cancer

Researchers are investigating whether lignans in flaxseed 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, flaxseed-supplemented diet for 1 month had slower tumor progression than those who did not consume the diet. However, a study of about 47,000 men found that ALA omega-3 fatty acids may stimulate the growth of prostate tumors in men with advanced prostate cancer. The researchers found that men who were suffering from advanced prostate cancer had higher quantities of ALA from nonanimal as well as meat and dairy sources.

Skin cancer

Animal studies suggest that lignans from flaxseed may also offer some protection against skin cancer including, possibly, the prevention of metastatic spread of melanoma from the skin to the lungs.

Other uses

Although further research is needed, preliminary evidence suggests that omega-3 fatty acids may help protect against certain infections and treating a variety of conditions, including ulcers, migraine headaches, attention deficit/hyperactivity disorder, addiction, eating disorders, preterm labor, emphysema, psoriasis, glaucoma, Lyme disease, lupus, and panic attacks.

Flax is an annual plant that thrives in deep moist soils rich in sand, silt, and clay. The small, oval-shaped seeds of the flax plant contain oil (sometimes called linseed oil).

Flaxseed contains several phyto (plant) compounds that may be beneficial in humans, including:

• Fiber (including soluble and insoluble)
• Protein -- approximately 20%
• Lignans
• Essential fatty acids (ALA) -- flaxseed is approximately 35% oil, of which 55% is ALA.

The laxative effect of flaxseed is due to its fiber and mucilage content. As described earlier, phytoestrogens, known as lignans, appear to play a role in the cancer protective effects of this plant. Other health benefits of flaxseed (such as protection from heart disease and arthritis) are likely due to its high concentration of the omega-3 fatty acid ALA.

Flaxseed oil should be refrigerated. Use whole flaxseeds within 24 hours of grinding, otherwise the ingredients lose their activity. Flaxseeds are also available ground in a special mylar package so that the components in the flaxseeds stay active. Ripe seeds, linseed cakes, powder, capsules, and flaxseed oil are all available at health food and grocery stores.

Pediatric

Flaxseed oil may be added to a child's diet to help balance fatty acids. If an infant is breastfed, the mother may ingest oil or fresh ground seed to increase fat content in breast milk. See adult dosage below.

Children (2 - 12 years): 1 teaspoonful (tsp) daily of ground flaxseeds, or 1 tsp of fresh flaxseed oil for constipation.

Adult

Flaxseed: Take 1 tablespoonful (tbsp), 2 - 3 times daily or 2 - 4 tbsp, 1 time daily. Grind before eating and take with lots of water.

Flaxseed oil: Take 1 - 2 tablespoonfuls daily, or 1 - 2 capsules daily. Flaxseed oil is often used in a liquid form, which contains approximately 7 g of ALA per 15 mL tbsp, and contains approximately 130 calories.

As a substitute for fish oil, a dose of 7.2 grams of flaxseed is approximately equivalent to 1 gram of fish oil.

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, contain components 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 health care provider qualified in the field of botanical medicine.

• Although studies have found that regular consumption of fish (which includes the omega-3 fatty acids EPA and DHA) may reduce the risk of macular degeneration, a recent study including two large groups of men and women found that diets rich in ALA may increase the risk of this disease. Ask your health care provider.
• Flaxseed may slow down the absorption of oral medications or other nutrients if taken at the same time. Therefore, flaxseed should be ingested several hours before, or after medicines or supplements. Talk to your health care provider before taking flaxseed if you regularly take any prescription or nonprescription medications, or dietary supplements.
• People with either diabetes or schizophrenia may lack the ability to convert ALA to EPA and DHA, the forms of omega-3 fatty acids that are generally made from ALA and are more readily used by the body. Therefore, people with these conditions should obtain their omega-3 fatty acids directly from dietary sources rich in EPA and DHA, such as cold water fish (including mackerel, salmon, or whitefish).
• Do not use flaxseed products or ALA if you have diabetes, prostate problems, breast cancer, or schizophrenia without the advice and supervision of a qualified health care provider.

Flaxseed supplements may alter the effects of some prescription and nonprescription medications. If you are currently being treated with any of the following medications, you should not use flaxseed without first talking to your health care provider:

Blood-Thinning Medications -- Omega-3 fatty acids may increase the effects of blood-thinning medications, including aspirin and warfarin. While the combination of aspirin and omega-3 fatty acids may be helpful under certain circumstances (such as heart disease), they should only be taken together under the guidance and supervision of a qualified health care provider.

Diabetic Medications -- If you are taking medicines for diabetes, including insulin, you should only use flaxseed (ALA) under the supervision of a qualified health care provider.

Oral Contraceptives or Hormonal replacement therapy (HRT) -- Flaxseed may alter hormonal levels and alter the effects of oral contraceptives or HRT. Only use flaxseed under the supervision of a qualified health care provider if you are taking hormonal altering medications such as oral contraceptives or HRT.

Other -- Avoid taking flaxseed at the same time of day as medications and other supplements, as it may slow down the absorption of oral medications or other nutrients if taken at the same time. Take the flaxseed either 1 hour before or 2 hours after taking any prescription or nonprescription medicine or dietary supplement.

Angerer P, von Schacky C. n-3 polyunsaturated fatty acids and the cardiovascular system. Curr Opin Lipidol. 2000;11(1):57-63.

Appel LJ. Nonpharmacologic therapies that reduce blood pressure: a fresh perspective. Clin Cadiol. 1999;22(Suppl. III):III1-III5.

Arnold LE, Kleykamp D, Votolato N, Gibson RA, Horrocks L. Potential link between dietary intake of fatty acid and behavior: pilot exploration of serum lipids in attention-deficit hyperactivity disorder. J Child Adolesc Psychopharmacol. 1994;4(3):171-182.

Boelsma E, Hendriks HF. Roza L. Nutritional skin care: health effects of micronutrients and fatty acids. Am J Clin Nutr. 2001;73(5):853-864.

Bommareddy A, Arasada BL, Mathees DP, Dwivedi C. Chemopreventive effects of dietary flaxseed on colon tumor development. Nutr Cancer. 2006;54(2):216-22.

Bruinsma KA, Taren DL. Dieting, essential fatty acid intake, and depression. NutritionRev. 2000;58(4):98-108.

Caron MF, White CM. Evaluation of the antihyperlipidemic properties of dietary supplements. Pharmacotherapy. 2001;21(4):481-487.

Cellini M, Caramazzu N, Mangiafico P, Possati GL, Caramazza R. Fatty acid use in glaucomatous optic neuropathy treatment. Acta Ophthalmol Scand Suppl. 1998;227:41-42.

Cho E, Hung S, Willet WC, Spiegelman D, Rimm EB, Seddon JM, et al. Prospective study of dietary fat and the risk of age-related macular degeneration. Am J Clin Nutr. 2001;73(2):209-218.

Clark WF, Kortas C, Heidenheim AP, Garland J, Spanner E, Parbtani A. Flaxseed in lupus nephritis: a two–year nonplacebo-controlled crossover study. J Am Coll Nutr. 2001;20(2 Suppl):143-148.

Curtis CL, Hughes CE, Flannery CR, Little CB, Harwood JL, Caterson B. N-3 fatty acids specifically modulate catabolic factors involved in articular cartilage degradation. J Biol Chem. 2000;275(2):721-724.

Dahl WJ, Lockert EA, Cammer AL, Whiting SJ. Effects of flax fiber on laxation and glycemic response in healthy volunteers. J Med Food. 2005;8(4):508-11.

deDeckere EAM, Korver O, Verschuren PM, Katan MB. Health aspects of fish and n-3 polyunsaturated fatty acids from plant and marine origin. Eur J Clin Nutr. 1998;52(10):749-753.

de Logeril M, Salen P, Martin JL, Monjaud I, Delaye J, Mamelle N. Mediterranean diet, traditional risk factors, and the rate of cardiovascular complications after myocardial infarction: final report of the Lyon Diet Heart Study. Circulation. 1999;99(6):779-785.

Demark-Wahnefried W, Price DT, Polascik TJ, 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. 2001;58(1):47-52.

Deutch B. Menstrual pain in Danish women correlated with low n-3 polyunsaturated fatty acid intake. Eur J Clin Nutr. 1995;49(7):508-516.

Dodin S et al. Flaxseed on cardiovascular disease markers in healthy menopausal women: a randomized, double-blind, placebo-controlled trial. Nutrition. 2008;24(1):23-30.

Dodin S, Lemay A, Jacques H, Legare F, Forest JC, Masse B. The effects of flaxseed dietary supplement on lipid profile, bone mineral density, and symptoms in menopausal women: a randomized, double-blind, wheat germ placebo-controlled clinical trial. J Clin Endocrinol Metab. 2005;90(3):1390-7.

Edwards R, Peet M, Shay J, Horrobin D. Omega-3 polyunsaturated fatty acid levels in the diet and in red blood cell membranes of depressed patients. J Affect Disord. 1998;48(2-3):149-155.

Freeman VL, Meydani M, Yong S, Pyle J, Flanigan RC, Waters WB, Wojcik EM. Prostatic levels of fatty acids and the histopathology of localized prostate cancer. J Urol. 2000;164(6):2168-2172.

Frieri G, Pimpo MT, Palombieri A, Melideo D, Marcheggiano A, Caprilli R, et al. Polyunsaturated fatty acid dietary supplementation: an adjuvant approach to treatment of Helicobacter pylori infection. Nut Res. 2000;20(7):907-916.

Geerling BJ, Badart-Smook A, van Deursen C, van Houwelingen AC, Russel MG, Stockbrugger RW, et al. Nutritional supplementation with N-3 fatty acids and antioxidants in patients iwth Crohn's disease in remission: effects on antioxidant status and fatty acid profile. IBD. 2000;6(2):77-84.

GISSI-Prevenzione Investigators. Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Lancet. 1999;354:447-455.

Griel AE, Kris-Etherton PM, Hilpert KF, Zhao G, West SG, Corwin RL. An increase in dietary n-3 fatty acids decreases a marker of bone resorption in humans. Nutr J. 2007;6(1):2 [Epub ahead of print].

Hall C 3rd, Tulbek MC, Xu Y. Flaxseed. Adv Food Nutr Res. 2006;51:1-97.

Hallund J, Tetens I, Bugel S, Tholstrup T, Ferrari M, Teerlink T, Kjaer A, Wiinberg N. Daily consumption for six weeks of a lignan complex isolated from flaxseed does not affect endothelial function in healthy postmenopausal women. J Nutr. 2006;136(9):2314-8.

Haggans CJ, Hutchins AM, Olson BA, Thomas W, Martini MC, Slavin JL. Effect of flaxseed consumption on urinary estrogen metabolites in postmenopausal women. Nutr Canc. 1999;33(2):188-195.

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(1):83-7.

Harris WS. N-3 fatty acids and serum lipoproteins: human studies. Am J Clin Nutr. 1997;65(5):1645S (10).

Hibbeln JR, Salem N, Jr. Dietary polyunsaturated fatty acids and depression: when cholesterol does not satisfy. Am J Clin Nut. 1995;62(1):1-9.

Holman RT, Adams CE, Nelson RA, Grater SJ, Jaskiewicz JA, Johnson SB, et al. Patients with anorexia nervosa demonstrate deficiencies of selected essential fatty acids, compensatory changes in nonessential fatty acids and decreased fluidity of plasma lipids. J Nutr 1995;125:901-907.

Hrboticky N, Zimmer B, Weber PC. 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. 1996;7:465-471.

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;69:890-897.

Hutchins AM, Martini MC, Olson BA, Thomas W, Slavin JL. Flaxseed consumption influences endogenous hormone concentrations in postmenopausal women. Nutr Cancer. 2001;39(1):58-65.

Jenab M, Thompson LU. The influence of flaxseed and lignans on colon carcinogenesis and ß-glucuronidase activity. Carcinogenesis. 1996;17(6):1343-1348.

Klurfeld DM, Bull AW. Fatty acids and colon cancer in experimental models. Am J Clin Nut. 1997;66(6 Suppl):1530S-1538S.

Kremer JM. N-3 fatty acid supplements in rheumatoid arthritis. Am J Clin Nutr. 2000;(suppl 1):349S-351S.

Kris-Etherton P, Eckel RH, Howard BV, St. Jeor S, Bazzare TL. AHA Science Advisory: Lyon Diet Heart Study. Benefits of a Mediterranean-style, National Cholesterol Education Program/American Heart Association Step I Dietary Pattern on Cardiovascular Disease. Circulation. 2001;103:1823

Kurzer MS, Xu X. Dietary phytoestrogens. Ann Rev Nutr. 1997;17:353-381.

Laugharne JD, Mellor JE, Peet M. Fatty acids and schizophrenia. Lipids. 1996;31(Suppl):S-163-165.

LaValle JB, Krinsky DL, Hawkins EB, et al. Natural Therapeutics Pocket Guide. Hudson, OH:LexiComp; 2000: 435.

Leitzmann MF, Stampfer MJ, Michaud DS, Augustsson K, Colditz GC, Willett WC, Giovannucci EL. Dietary intake of n-3 and n-6 fatty acids and the risk of prostate cancer. Am J Clin Nutr. 2004;80(1):204-16.

Lewis JE, Nickell LA, Thompson LU, Szalai JP, Kiss A, Hilditch JR. A randomized controlled trial of the effect of dietary soy and flaxseed muffins on quality of life and hot flashes during menopause. Menopause. 2006;13(4):631-42.

Lockwood K, Moesgaard S, Hanioka T, Folkers K. Apparent partial remission of breast cancer in 'high risk' patients supplemented with nutritional antioxidants, essential fatty acids, and coenzyme Q10. Mol Aspects Med. 1994;15Suppl:s231-s240.

Lorenz-Meyer H, Bauer P, Nicolay C, Schulz B, Purrmann J, Fleig WE, et al. Omega-3 fatty acids and low carbohydrate diet for maintenance of remission in Crohn's disease. A randomized controlled multicenter trial. Study Group Members (German Crohn's Disease Study Group). Scan J Gastroenterol. 1996;31(8):778-785.

Lucas EA, Wild RD, Hammond LJ, Khalil DA, Juma S, Daggy BP, Stoecker BJ, Arjmandi BH. Flaxseed improves lipid profile without altering biomarkers of bone metabolism in postmenopausal women. J Clin Endocrinol Metab. 2002;87(4):1527-32.

Mandasescu S, Mocanu V, Dascalita AM, Haliga R, Nestian I, Stitt PA, Luca V. Flaxseed supplementation in hyperlipidemic patients. Rev Med Chir Soc Med Nat Iasi. 2005;109(3):502-6.

Meydani M. Omega-3 fatty acids alter soluble markers of endothelial function in coronary heart disease patients. Nutr Rev. 2000;58(2 pt 1):56-59.

Moyad M. Soy, disease prevention, and prostate cancer. Sem Urol Oncol. 1999;17(2):97-102.

Mozaffarian D. Does alpha-linolenic acid intake reduce the risk of coronary heart disease? A review of the evidence.Altern Ther Health Med. 2005;11(3):24-30; quiz 31, 79.

Nestel PJ, Pomeroy SE, Sasahara T, et al. Arterial compliance in obese subjects is improved with dietary plant n-3 fatty acid from flaxseed oil despite increased LDL oxidizability. Arterioscler Thromb Vasc Biol. July 1997;17(6):1163-1170.

Newcomer LM, King IB, Wicklund KG, Stanford JL. The association of fatty acids with prostate cancer risk. Prostate. 2001;47(4):262-268.

Peet M, Laugharne JD, Mellor J, et al. Essential fatty acid deficiency in erythrocyte membranes from chronic schizophrenic patients, and the clinical effects of dietary supplementation. Prostaglandins Leukot Essent Fatty Acids. 1996;55(1-2):71-75.

Prasad K. Reduction of serum cholesterol and hypercholesterolemic atherosclerosis in rabbits by secoisolariciresinol diglucoside isolated from flaxseed. Circulation. 1999;99(10):1355-1362.

Prasad K. Dietary flaxseed in prevention of hypercholesterolemic atherosclerosis. Atherosclerosis. 1997;132(1):69–76.

Prisco D, Paniccia R, Bandinelli B, et al. Effect of medium term supplementation with a moderate dose of n-3 polyunsaturated fatty acid on blood pressure in mild hypertensive patients. Thromb Res. 1998;91:105-112.

Pruthi S et al. Pilot evaluation of flaxseed for the management of hot flashes. J Soc Integr Oncol. 2007;5(3):106-12.

Rose DP, Connolly JM, Coleman M. Effect of omega-3 fatty acids on the progression of metastases after the surgical excision of human breast cancer cell solid tumors growing in nude mice. Clin Can Res. 1996;2:1751-1756.

Schwab US, C Callaway J, Erkkila AT, Gynther J, Uusitupa MI, Jarvinen T. Effects of hempseed and flaxseed oils on the profile of serum lipids, serum total and lipoprotein lipid concentrations and haemostatic factors. Eur J Nutr. 006;45(8):470-7.

Seddon JM, Rosner B, Sperduto RD, Yannuzzi L, Haller JA, Blair NP, Willett W. Dietary fat and risk for advanced age-related macular degeneration. Arch Opthalmol. 2001;119(8):1191-1199.

Serraino M, Thompson LY. Flaxseed supplementation and early markers of colon carcinogenesis. Cancer Lett. 1992;63(2):159-165.

Simopoulos AP. Essential fatty acids in health and chronic disease. Am J Clin Nutr. 1999;70(30 Suppl):560S-569S.

Simopoulos AP. Human requirement for N-3 polyunsaturated fatty acids. Poult Sci. 2000;79(7):961-970.

Soyland E, Funk J, Rajka G, Sandberg M, Thune P, Ruistad L, et al. Effect of dietary supplementation with very-long chain n-3 fatty acids in patients with psoriasis. NEJM. 1993;328(25):1812-1816.

Stuglin C, Prasad K. Effect of flaxseed consumption on blood pressure, serum lipids, hemopoietic system and liver and kidney enzymes in healthy humans. J Cardiovasc Pharmacol Ther. 2005;10(1):23-7.

Sung MK, Lautens M, Thompson LU. Mammalian lignans inhibit growth of estrogen-independent human colon tumor cells. Anticancer Research. 1998;18(3A):1405-1408.

von Schacky C, Angere P, Kothny W, Theisen K, Mudra H. The effect of dietary omega-3 fatty acids on coronary atherosclerosis: a randomized, double-blind, placebo-controlled trial. Ann Intern Med. 1999;130:554-562.

Voskuil DW, Feskens EJM, Katan MB, Kromhout D. Intake and sources of alpha-linolenic acid in Dutch elderly men. Euro J Clin Nutr. 1996;50(12):784-787.

Yan L. Dietary flaxseed supplementation and experimental metastasis of melanoma cells in mice. Cancer Letters. 1998;124:181-186.

Zambón D, Sabate J, Munoz S, et al. Substituting walnuts for monounsaturated fat improves the serum lipid profile of hypercholesterolemic men and women. Ann Intern Med. 2000;132:538-546.

Zhang W, Wang X, Liu Y, Tian H, Flickinger B, Empie MW, Sun SZ. Dietary flaxseed lignan extract lowers plasma cholesterol and glucose concentration in hypercholesterolaemic subjects. Br J Nutr. 2008;99(6):1301-9.