Lignans: Beyond Flaxseed Oil
Dallas Clouatre, Ph.D.
Flaxseed is one of the world's oldest foods. It was consumed by the ancient Babylonians more than 5,000 years ago and was prized by the Greeks and Romans for its health-promoting benefits. The seeds supply both essential fatty acids and fiber, much of it soluble like that found in fruit and oat bran. Recent research has brought to light yet more benefits from components contained within flaxseed fiber known as lignans.
Many health-conscious shoppers are familiar with flax oil. Approximately 41 percent of flaxseed consists of fatty acids, of which about 70 percent is polyunsaturated. There is a high ratio of alpha-linolenic acid (an omega-3 fatty acid) to linoleic acid (an omega-6 fatty acid). More than half the fat in flaxseed is of the omega-3 fatty acid type. Both alpha-linolenic acid and linoleic acid are essential because the body cannot manufacture them from any other substances, yet they are the parent compounds for many physiologically active substances, such as eicosanoids. The average American's diet supplies a ratio of the two which is roughly 1:20 in favor of omega-6, whereas an ideal ratio of omega-3 to omega-6 fatty acids is between 1:1 and 1:3. Therefore, eating flaxseed or flaxseed oil can help to balance the ratio of these fatty acids found in the normal diet. Omega-3 fatty acids protect against coronary heart disease, stroke, hypertension, inflammation, autoimmune disorders and a number of cancers.
What Are Flax Lignans?
Several years ago, I first ran across lignans, another component found in flaxseed that helps to defend against sex-based cancers in both women and men. (See The Prostate Miracle, Kennsington Books, 2000.) Lignans are a group of sugar-like molecules that are found in plants, especially the seeds. Lignans should not be confused with lignin, which is an insoluble fiber that is structurally related. Indeed, in the plant world, lignans might be said to be the building blocks for lignin. Lignans are especially abundant in flaxseed, with some authorities estimating that flax contains from 75 to 800 times as much of these items as do other food sources. Flax lignans form fibrous chains that effectively bind toxins found in the gastrointestinal tract.
However, flax lignans are far more than just fiber. Lignans are phytoestrogens, that is, plant compounds which weakly resemble estrogens, the female sex hormones produced in the human body in both women and men. Other such phytoestrogenic compounds included isoflavones, coumestans, flavonoids and phytosterols. Phytoestrogens can compete for receptor sites with the body's own estrogen when estrogen levels are high or supplement estrogenic activity when estrogen levels are low. Just as significantly, they complete with what are known as xenoestrogens. Xenoestrogens are harmful estrogen-like molecules from the environment, such as are found in pesticides, solvents, adhesives, soap emulsifiers, plastics, PCB's, etc. One reason that