Table of Contents


Flaxseed is the seed of the plant Linum usitatissi-mum It is a rich source of alpha-linolenic acid (ALA), an essential nutrient in the human diet. Flaxseed has health and possibly medical benefits. Flaxseed oil is a vegetable oil derived from pressed flaxseed. Flaxseed.

and flaxseed oil have different properties and nutritional values.


Flaxseed is a good source of ALA and is thought to improve health by lowering blood cholesterol. Flax-seeds may also protect against certain cancers. It can also be used as a laxative.


L. usitatissimum is a slender plant with narrow leaves and blue flowers that grows anywhere from 8– 45 in (20–130 cm) tall. The plant originated in India but has been farmed across the world for thousands of years. Archeologists discovered evidence that flax was cultivated in ancient Babylon as early as 3,000 B.C. Today, in Europe and Asia, a tall variety of flax is grown primarily for its fibers, which are used to make linen. A shorter, bushier variety is grown for its seeds in North America. The Canadian provinces of Alberta, Manitoba, and Saskatchewan are the leading producers of flax in North America. North Dakota produces most of the flax grown in the United States.

Seed flax is grown for both consumption and industrial use. The seed is about 42% oil. Solvent-extracted oil from flax seeds is used for industrial purposes and is often called linseed oil. It is used in manufacturing oil paints, varnishes, and linoleum. The material that remains after oil has been extracted from the seeds is called linseed cake or linseed meal. It is often added to animal feed as a protein and omega-3 fatty acid supplement. Omega-3 enriched eggs, for example, come from chickens fed flax. Omega-3 enriched pork is available in.


Dietary supplement—A product, such as a vitamin, mineral, herb, amino acid, or enzyme, that is intended to be consumed in addition to an individual’s diet with the expectation that it will improve health.

Fatty acids—Complex molecules found in fats and oils. Essential fatty acids are fatty acids that the body needs but cannot synthesize. Essential fatty acids are made by plants and must be present in the diet to maintain health.

Lignans—A group of compounds found in plants that have characteristics similar to the female hormone estrogen. They appear to have some anti-cancer and anti-oxidant effects.

Triglycerides—A type of fat found in the blood. High levels of triglycerides can increase the risk of coronary artery disease.

Canada and Japan. The fiber in the stems of seed flax is used in the production of cigarette papers.

Human consumption of flaxseed and flaxseed oil has increased substantially since the mid-1990s. Flax-seed oil for human consumption is produced through solvent-free cold pressing at low temperatures. The oil is sold in bottles to be used as food or in capsules to be taken as a dietary supplement.

Flax seeds come in brown, golden, and yellow varieties and have a slightly nutty flavor. All colors of seed have the same nutritional value. Seeds are sold whole or ground (milled flax). Whole seeds can be stored at room temperature for up to one year. Ground seeds are easier to digest than whole seeds, but they spoil and develop an unpleasant taste more rapidly. Ground seeds can be kept in an airtight container in the refrigerator for up to three months. However, when ground flax is needed, it is preferable to grind whole seeds in a coffee grinder, blender, or food processor immediately before use. Flaxseed and flax-seed oil are sold primarily in health food stores or by mail order.

Nutritional information

Flaxseed is an excellent source of alpha-linolenic acid. ALA is an essential fatty acid for humans. Essential fatty acids are molecules the body needs but cannot synthesize for itself from other nutrients. Thus, essential fatty acids, just like essential vitamins, must be obtained through diet. Eating 1 tbsp (8 g) of ground flax or 1 tsp (5 g) of flax oil provides enough ALA to meet daily diet requirements.

According to the Flax Council of Canada, 1 tbsp ground flaxseed provides about 36 calories, 1.8 g of ALA, 1.6 g of protein, and 2.2 grams of dietary fiber. Ground flax is preferred over whole seeds because it is easier to digest. One teaspoon of flax oil provides 44 calories and 2.8 g of ALA, but contains no protein or fiber. The oil in flaxseed is very high in polyunsatu-rated fat (a healthy type of fat) and contains no trans fat or cholesterol. Flaxseed also provides vitamins C, E, K, B1 (thiamin), B2 (riboflavin), and B6, along with the mineralscalcium, iron, magnesium, phosphorous, zinc, copper, manganese, and selenium Flaxseed is low in sodium and carbohydrates The seed, but not the oil, is also an excellent source of lignin, a nutrient thought to have anti-cancer properties.

Flaxseed can be added to the diet in several ways. Ground, a daily serving can be sprinkled on hot or cold cereal or mixed into yogurt or smoothies. Larger amounts can be added to pancake or waffle mix or baked goods such as muffins or cookies. Flax oil can be added to salad dressings or smoothies. Frying in flax oil is not recommended. Three tablespoons of ground flax can replace one tablespoon of butter, margarine, or vegetable oil in recipes. One tablespoon of ground flax mixed with three tablespoons of water, when left to stand for two minutes before use, can replace one egg in many recipes.

Health claims

Major health claims for flaxseed and flax oil arise from the fact that these products contain high levels of ALA. ALA can be converted by the body into two different long chain omega-3 fatty acids. Long chain omega-3 fatty acids have been shown to lower the risk of heart attack in people with heart disease. They appear to lower the level of cholesterol in the blood, especially low-density lipoprotein (LDL) or “bad” cholesterol. Other health claims for omega-3 fatty acids include lowering blood pressure, lowering trigly-cerides (fats) in the blood, and reducing the tendency of blood to clot in veins.

Another health claim for flaxseed (but not flax oil) is that it has anti-cancer properties. Flaxseed and sesame seed both contain large amounts of lignans. Lignans are naturally occurring molecules found in plants that mimic the effect of the female hormone estrogen. Lignans compete with estrogen for binding sites on cells. They can either act as antagonists and lessen the estrogen response where there is continual estrogen exposure (increasing risk of breast cancer) or they can mimic estrogen and boost the response where exposure is limited (post menopause) helping to prevent post menopausal symptoms. Few well-designed, well-controlled human studies of the effect of lignans on cancer have been completed. Although the results of animal studies are encouraging, there is not enough evidence to say that lignans, or flaxseed, can slow or prevent cancer.

Researchers generally agree that ground flaxseed is an effective laxative. Flaxseed provides dietary fiber and, along with the oil it naturally contains, helps move material through the bowel. Whole seed may have the reverse effect, swelling and blocking the bowel.

Some studies have shown that flaxseed oil supplements can reduce symptoms of attention deficit-hyperactivity disorder (ADHD) in some children. Other studies claim that flaxseed can lower blood sugar levels in people with diabetes. Initial results also suggest that flaxseed may reduce symptoms of menopause. None of these health claims have been substantiated with large, well-controlled human studies.


ALA, which is found in large quantities in flax-seed, appears to increase the risk of developing prostate cancer. This finding is preliminary and not yet substantiated. Individuals with prostate cancer or a history of prostate cancer should consult their oncologist before using flax products.

Although no health risks are known when flaxseed and flax oil are used in reasonable and moderate quantities, no studies have been done on the safety of flax in pregnant or breastfeeding women or in children.


No specific drug interactions are known.


Complications are unlikely to occur when flax products are used to meet daily dietary needs. Whole flaxseed can cause blockage of the intestines when taken with inadequate amounts of liquids.

Parental concerns

Parents should be aware that the safe dose of many herbal supplements has not been established for children. Accidental overdose may occur if children are given adult dietary supplements.


Muir, Alister D., and Neil D. Westcott, eds. Flax: The Genus Linum New York: Routledge 2003.

PDR for Herbal Medicines, 3rd ed. Montvale, NJ: Thompson Healthcare, 2004.

Pierce, Andrea. The American Pharmaceutical Association Practical Guide to Natural Medicines New York: William Morrow, 1999.

Reinhardt-Martin, Jane. The Amazing Flax Cookbook Moline: IL, TSA Press, 2004.

Wildman, Robert E. C., ed. Handbook of Nutraceuticals and Functional Foods, 2nd ed. Boca Raton, FL: CRC/ Taylor&Francis, 2007.


Covington, M. B. “Omega-3 Fatty Acids.” American Family Physician 70, no.1 (2004): 133-40.


Alternative Medicine Foundation. P.O. Box 60016, Potomac, MD 20859. Telephone: (301) 340-1960. Fax: (301) 340-1936. Website: <>.

Flax Council of Canada. 465-167 Lombard Avenue, Winnipeg, MB R3B 0T6. Telephone: (204) 982-2115. Fax: (204) 942-1841. Website: <>

Natural Standard. 245 First Street, 18th Floor, Cambridge, MA 02142. Telephone: (617) 444-8629. Fax: (617) 444-8642. Website: <>

Office of Dietary Supplements, National Institutes of Health. 6100 Executive Blvd., Room 3B01, MSC 7517, Bethesda, MD 20892-7517. Telephone: (301) 435-2920. Fax: (301) 480-1845. Website: <>


Carter, Jack. “Flaxseed as Functional Food for People and as Feed for Other Animals.”North Dakota State University. [cited May 7, 2007].<>

Flax FAQ Flax Council of Canada. [cited May 7, 2007].<>

Martin, Diane H. “Food Sources of Alpha-Linolenic Acid.”Flax Council of Canada. November 2005. [cited May 7,2007].>

Natural Standard Research Collaboration. “Flaxseed and Flaxseed Oil. (Linum usitatissimum)MedlinePlusJanuary 23, 2007. [cited May 7, 2007]. <>

Tish Davidson, A.M.