The health benefits attributed to flaxseed in the diet are almost too numerous to mention. It reportedly offers protection against heart disease, cancer, and diabetes. It lowers cholesterol and high blood pressure and is effective for relieving symptoms of irritable bowel syndrome, asthma, and migraines. Flaxseed helps people relax and improves sleep. It restores hormonal balance in women, and improves dry eye syndrome. Back in the 1950s, a German biochemist by the name of Joanna Budwig is famous for successfully treating terminally ill cancer patients by feeding them her prescribed diet including a combination of flaxseed oil and cottage cheese.
Do not rush out to buy flaxseed just yet, at least according to Nutrition Action Newsletter, a reputable publication from the Center for Science in the Public Interest. According to a December 2005 article titled Just the Flax- A Miracle Seed Comes Down to Earth, there is only limited evidence that alpha-linolenic acid (ALA), one of the main ingredients of flaxseed, can protect the heart. The article also cites a 2005 study involving 45,000 men that found those who ate the highest amounts of ALA were more likely to develop advanced prostate cancer than those who ate the least ALA. The author was quick to point out that flax was not singled out, and the cancer rate was linked to ALA intake from all sources. In other words, proceed with caution.
Flaxseed is also contains extremely high levels of potent antioxidants called lignans, known best for their cancer fighting properties. Nutrition Action cites a Finnish study that reported women with the highest blood levels of lignans were 60% less likely to have breast cancer. Unfortunately, 29 of the 194 women who did develop breast cancer had some of the highest levels. Three years later the study was repeated and found no link between lignans and the incidence of breast cancer.
Confused? So are the experts. Mayoclinic.com has evaluated the data from flaxseed research and found its use as a laxative the only benefit that graded higher than unclear scientific evidence exists.
If you do not like fish, healthy aging expert Dr. Andrew Weil recommends whole flaxseed as a source of omega-3 fatty acids, but is less enthusiastic about flaxseed oil, expressing concerns about spoilage and the lack of lignans which are often removed during processing.
An article by Harvard Health Publications sums of the confusion best by concluding this: It is too early to say whether flaxseeds are right for you. They do contain lignans that function as phytoestrogens- but so does soy. They are very rich in ALA, which may reduce the risk of heart disease-but may also increase the risk of developing prostate cancer in men.
There might be something there, but it is clear we do not have all of the answers yet on the benefits or risks of taking flaxseed.