Flaxseed seed, the seed of the flax plant, grows all over Canada and the Northwestern part of the United States. It is believed to have originated in Egypt. From flaxseed, flaxseed oil is extracted. Both have been used to potentially lower cholesterol levels and play a part in preventing cancer.
Flaxseed can be taken by mouth or mixed with juice or water, crushed or whole; flaxseed oil is readily available in liquid form or as a capsule.
Find out what the National Institute of Health (NIH) affirms about flaxseed and flaxseed oil, backed by scientific research.
- Flaxseed contains soluble fiber, like that found in oat bran, and may have a laxative effect.
- Studies of flaxseed preparations to lower cholesterol levels report mixed results. A 2009 review of the clinical research found that cholesterol-lowering effects were more apparent in postmenopausal women and in people with high initial cholesterol concentrations.
- Some studies suggest that alpha-linolenic acid (a substance found in flaxseed and flaxseed oil) may benefit people with heart disease. But not enough reliable data are available to determine whether flaxseed is effective for heart conditions.
- Study results are mixed on whether flaxseed decreases hot flashes.
- Although some population studies suggest that flaxseed might reduce the risk of certain cancers, there is not enough research to support a recommendation for this use.
- NCCAM is funding studies on flaxseed. Recent studies are looking at its potential role in preventing or treating atherosclerosis (hardening of the arteries), breast cancer, and ovarian cysts.
Side Effects and Cautions
- Flaxseed and flaxseed oil supplements seem to be well tolerated. Few side effects have been reported.
- Flaxseed, like any supplemental fiber source, should be taken with plenty of water; otherwise, it could worsen constipation or, in rare cases, even cause intestinal blockage. Both flaxseed and flaxseed oil can cause diarrhea.
- The fiber in flaxseed may lower the body's ability to absorb medications that are taken by mouth. Flaxseed should not be taken at the same time as any conventional oral medications or other dietary supplements.
- Tell all your health care providers about any complementary health practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
From NIH.gov