Flaxseed review

Medscape has published 2 case histories. One patient wants to take flaxseed to improve cholesterol levels and diabetes control. The other has constipation and premenstrual symptoms.

Here’s what we know.

Constipation and other intestinal symptoms

• In people with irritable bowel syndrome, roughly ground flaxseed improves constipation, bloating, and abdominal pain vs psyllium.
• Flax supplement taken by mouth or baked in food increases fecal weight equivalent to psyllium.

Heart health and diabetes

• Ground flaxseed added to baked goods decreases LDL (bad) cholesterol modestly and briefly.
• Flaxseed is also associated with lower HDL (good) cholesterol.
• No long-term studies of flaxseed vs other treatments show significant clinically important cardiovascular outcomes.
• Evidence of benefit in diabetes and high blood pressure is poor or lacking.

Menstrual disorders, menopause, pregnancy

• Benefit from flaxseed (not flaxseed oil) for premenstrual breast pain is reported when eaten in a muffin daily for 6 months.
• Insufficient human evidence to recommend flaxseed or flaxseed oil during pregnancy and lactation.
• In postmenopausal women, supplementation with flaxseed isn’t associated with changes in blood levels of hormones or markers of bone metabolism compared to soy.
• Also in postmenopausal women, flaxseed-containing muffins aren’t associated with changes in menopause-specific quality of life or hot flash symptoms.

The bottom line?
The data are thin.

The authors reference the Natural Standard Resource Collaboration (website link), which concludes, “most of the studies were based on the alpha-linoleic acid (ALA) component and almost all were of poor quality, with no evidence to support recommending this product for any condition at this time.”

7/15/08 22:43 JR