Food sources include whole flaxseed, flaxseed oil, margarine made from flaxseed oil, flax cereals, and bread made with ground flaxseed flour.

There are many media and marketing claims for the benefits of flaxseed supplementation. Some key points follow.

1. Reduces the risk for heart disease and stroke.

At this time there is insufficient research to support the claim that flaxseed reduces risk of stroke and heart attack. Flaxseed appears to raise cellular eicosapentaenoic acid levels under certain conditions but has not consistently lowered serum LDL cholesterol and triglycerides.

2. Improves symptoms of lupus, eczema, and other inflammatory diseases.

Flaxseed has been shown to inhibit mediators of inflammation, but clinical trials are needed to determine the effects on rheumatoid arthritis, psoriasis, multiple sclerosis, and lupus. Several researchers have suggested that the low ratio of n-3 to n-6 fatty acids in the average American diet creates an imbalance that is linked to these conditions. Consuming flaxseed products is one way to increase the n-3 content of the diet. Other food sources of n-3 fatty acids include walnuts, soybean and canola oil, and fatty fish.

3. Reduces the risk of estrogen-related and other cancers.

Some evidence from experimental studies in animals suggests that flaxseed inhibits tumor growth, specifically mammary tumors. Flaxseed supplementation seems to increase urinary excretion of estrogen metabolites associated with a reduced breast cancer risk in postmenopausal women. Larger, long-term trials are needed in humans to determine the role of flaxseed in cancer prevention.

4. Relieves constipation.

Consumption of flaxseed products can increase the fiber and n-3 fatty acid content of the diet and thus may be effective in treating constipation. However, tolerance may be poor unless adequate fluid/water is taken along with flaxseed to avoid gastrointestinal distress.

Information for this article provided by the American Dietetic Association.