Why is flax seed a good dietary supplement?

Flax seed contains Omega-3 and Omega-6 fatty acids, lignans and has a high fiber content.  Each of these components has specific health benefits.

Omega-3 fatty acids:  Flax seed is a rich source alpha-linolenic acid, an essential fatty acid of the Omega-3 family.  Essential fatty acids are components that are necessary for the proper function of the human body but are components that our body cannot manufacture from other nutritional building blocks.  'Essential' in this context means that the human body needs this nutrition building block for bodily functions.  Omega-3 fatty acids may regulate gene transcription and expression, ¹.  Omega-3 fatty acids affect coronary heart disease by reducing serum triglycerides and blood pressure².   Omega-3 fatty acids may also protect the body from some types of cancer and have also have beneficial effects on the immune system as well as inflammatory disease like atherosclerosis^{3, 4, 5}.  

Lignans:  Flax seed is a rich source of lignans, a type of phytoestrogen. Phytoestrogens are compounds found in plants that are found to have weak estrogen activities in animals.  Phytoestrogens are compounds that may protect against certain types of cancer by interfering with the effects of estrogen.  People with diets high in fiber and high in food sources that contain phytoestrogens such as lignans tend to have lower rates of hormone-dependent cancers such as breast cancer⁶.

Dietary Fiber:  Flax seed is a good source of dietary fiber containing 28 g total dietary fiber/100 g dry weight.  Approximately 2/3 of the fiber in flax seed is insoluble⁷.  Insoluble fiber helps prevent constipation by increasing bulk and reducing the time food passes through the bowel.  The remaining 1/3 of the fiber is water-soluble.  Water-soluble fiber has been documented to assist in lower blood cholesterol levels and maintaining blood glucose levels^{8, 10}. 

High fiber foods may offer protection against certain types of cancer¹¹.  Lower cancer rates of some hormone-dependent cancers such as breast, endometrium and prostrate in certain populations of people with high fiber diets may be attributed to  the amount of fiber in their diets⁶.  The high fiber in the diet may help to lower lipid blood levels as well as hormone levels⁶.  The lower fiber diets of Western populations may tend to elevate blood estrogen levels which in turn may stimulate tumor cell growth and cancer development¹².   

Recent scientific research about health benefits of flax.

Recent scientific reports point out that flax seed can have a positive influence on everything from cholesterol levels to constipation to cancer and heart disease.

Here are some highlights:

• Relief from constipation

Eating 50 grams of flax seed per day (baked into muffins) helped increase the frequency of bowel movements and the number of consecutive days with bowel movements in a group of older Canadian adults⁹.

• A lower risk for heart disease

Total cholesterol levels dropped 9 per cent and LDL (the "bad" cholesterol) decreased 18 per cent when a group of nine healthy women ate 50 grams of milled flax seed a day for four weeks (as flour or cooked into bread) along with their regular diets, according to a report from the University of Toronto.

In a similar study with men and women, 50 grams of flax seed (eaten daily in muffins) lowered total cholesterol and showed a constant trend of about 11 to 16 per cent lower serum lipids (fat in the blood).

• Cancer prevention

Lignans and alpha-linolenic acid are found abundantly in flax seed. Population studies of diet and disease risk suggest an anticancer role for flax seed. Long-term studies of flax seed effects in women with breast cancer are underway.