Researchers from the Chinese Academy of Sciences, in Shanghai reviewed the evidence.

First, the details.

  • Data from 28 studies were combined for the meta-analysis.

And, the results.

  • Flaxseed reduced total and LDL (bad) cholesterol by 0.10 mmol/L (3.9 mg/dL) and 0.08 mmol/L (3 mg/dL), respectively.
  • Significant reductions were observed with whole flaxseed and lignan (estrogen-like) supplements but not with flaxseed oil.
  • The cholesterol-lowering effects were more apparent under the following conditions.
    • Females (particularly postmenopausal women)
    • Individuals with high initial cholesterol concentrations
    • Higher quality studies
  • There was no effect on HDL cholesterol and triglycerides.

The bottom line?
The authors concluded, “Flaxseed significantly reduced circulating total and LDL cholesterol concentrations, but the changes were dependent on the type of intervention, sex, and initial lipid profiles of the subjects.”

More studies will be needed in order to determine the effect of flaxseed on lipid profiles in men and premenopausal women.

And, it’s potential for preventing cardiovascular disease will have to be studied.

As an update, researchers at Nippon Flour Mills Co., Ltd., in Kanagawa, Japan, studied 30 men with moderately high cholesterol levels. After 12 weeks of treatment, those who received 100 mg of Secoisolariciresinol diglycoside (an antioxidant in flax, as well as sunflower, sesame, and pumpkin seeds) exhibited a significant reduction in the ratio of LDL (bad):HDL (good) cholesterol compared to the group treated with placebo.

6/25/09 16:16 JR, updated 2/6/11 23:23 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.