Health Benefits of Flaxseeds

Ground flaxseeds (pictured left) and whole flaxseeds (right). Kristin Duvall/Photlibrary/Getty Images

What Is Flaxseed?

Flax is a plant that grows throughout Canada and the northwestern United States. Its seed, also known as linseed, contains soluble fiber, omega-3 fatty acids, and lignans (naturally occurring chemicals with estrogen-like effects).

Flaxseed is sold whole and in powder form. Derived from flaxseed, flaxseed oil is available in liquid and capsule form. It should be noted that flaxseed oil preparations lack lignans.

Uses for Flaxseed

In alternative medicine, flaxseed is purported to offer a number of health benefits, including treatment or prevention of these conditions:

  • constipation
  • high cholesterol
  • menopausal symptoms
  • premenstrual syndrome
  • periodontal disease
  • cancer

Health Benefits of Flaxseeds:

Although research on flaxseed's health effects is limited, studies suggest that flaxseed products may offer some benefits:

1) High Cholesterol

A number of human studies have shown that flaxseed can significantly reduce total and LDL ("bad") cholesterol levels, according to a research review published in 2009. However, flaxseed did not appear to considerably alter levels of HDL ("good") cholesterol. What's more, flaxseed's cholesterol-lowering effects were more apparent in females (especially postmenopausal women) and people with higher cholesterol levels.

2) Hot Flashes

Study results are mixed on whether flaxseed can cool hot flashes.

For instance, a pilot study published in 2007 found that six weeks of daily crushed-flaxseed consumption decreased hot flash activity in women not taking estrogen therapy. However, a more recent study concluded that regular intake of flaxseed is no more effective than a placebo for reducing hot flashes.

3) Constipation

A 2005 study of 26 healthy young adults found that daily flaxseed intake produced a laxative effect, suggesting that flaxseed may be useful in the treatment of constipation.

Flaxseed and Cancer

Although preliminary research is promising, there is a lack of evidence from human-based studies that flaxseed is effective in preventing or treating cancer.


Flaxseed should be taken with plenty of water; otherwise, it could worsen constipation or, in rare cases, even cause intestinal blockage.

Since whole flaxseeds may pass through your intestine undigested, nutrition experts often suggest grinding flaxseed (in a coffee grinder, for instance) before adding it to cereals, smoothies, and other foods.

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.

Although flaxseed and flaxseed oil supplements are generally considered safe, their intake may lead to increased bowel movements and/or flatulence.

Keep in mind that the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established. You can get additional tips on using supplements here.

Using Flaxseeds for Health

Due to the limited research, it's too soon to recommend flaxseeds as a treatment for any condition. If you're considering using it, talk to your doctor to weigh the potential risks and benefits. Keep in mind that alternative medicine should not be used as a substitute for standard care. Self-treating a condition and avoiding or delaying standard care may have serious consequences.


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.

National Center for Complementary and Alternative Medicine. "Flaxseed and Flaxseed Oil." NCCAM Publication No. D313. Created May 2006.
Updated April 2008.

Pan A, Yu D, Demark-Wahnefried W, Franco OH, Lin X. "Meta-analysis of the effects of flaxseed interventions on blood lipids." Am J Clin Nutr. 2009 90(2):288-97.

Pruthi S, Thompson SL, Novotny PJ, Barton DL, Kottschade LA, Tan AD, Sloan JA, Loprinzi CL. "Pilot evaluation of flaxseed for the management of hot flashes." J Soc Integr Oncol. 2007 5(3):106-12.

Simbalista RL, Sauerbronn AV, Aldrighi JM, Arêas JA. "Consumption of a Flaxseed-Rich Food Is Not More Effective Than a Placebo in Alleviating the Climacteric Symptoms of Postmenopausal Women." J Nutr. [Epub ahead of print]

Thompson LU, Chen JM, Li T, Strasser-Weippl K, Goss PE. "Dietary flaxseed alters tumor biological markers in postmenopausal breast cancer." Clin Cancer Res. 2005 15;11(10):3828-35.

Disclaimer: The information contained on this site is intended for educational purposes only and is not a substitute for advice, diagnosis or treatment by a licensed physician. It is not meant to cover all possible precautions, drug interactions, circumstances or adverse effects. You should seek prompt medical care for any health issues and consult your doctor before using alternative medicine or making a change to your regimen.

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