Flaxseed, also known as linseed, is the oval-shaped seed of the flax plant, a low-growing annual shrub that is known scientifically as Linum usitatissimum. Although flax is believed to have originated in the Middle East, the plant today grows widely throughout the world. Its seed is rich in both soluble and insoluble fiber, as well as alpha-linolenic acid. These components endow flaxseed with a variety of medicinal properties that have been the subject of extensive research.
Alpha-linolenic acid, or ALA, is an omega-3 fatty acid that is found in certain plant-based foods, including flaxseed. The intake of omega-3 fatty acids -- most of which are found in fish and other marine-based foods -- has been closely associated with improved cardiovascular health. A Canadian-Cuban research team analyzed data from prior studies to determine how the intake of ALA-rich flaxseed affected cardiovascular health. As they reported in the November 2010 issue of “The Canadian Journal of Cardiology,” their review confirmed that the cardiovascular health benefits of the ALA in flaxseed extend well beyond a lowering of cholesterol levels. They suggested that their findings provide a convincing case for randomized, controlled trials of dietary flaxseed or ALA among patients with symptoms of atherosclerotic heart disease.
To determine how the fatty acids in flaxseed and safflower seed affect the symptoms of sensitive skin, a team of French and German researchers assembled a study group of otherwise healthy volunteers with sensitive skin. Over the course of 12 weeks, some volunteers received flaxseed oil supplements, while others got safflower oil. Volunteers who received flaxseed oil showed significant decreases in skin sensitivity, roughness, scaling and transepidermal water loss, while skin smoothness and hydration improved. Those who got safflower oil only showed improved hydration and a reduction in roughness. In an article in a 2011 issue of “Skin Pharmacology and Physiology,” researchers reported that their findings provided evidence that daily flaxseed oil intake can reduce multiple symptoms of skin sensitivity.
A team of cancer and nutrition researchers from across the United States studied the effects of adding flaxseed to the diets -- both normal and reduced-fat -- of men diagnosed with prostate cancer. Researchers divided prostate patients into four groups: One ate a normal diet, a second ate a normal diet supplemented with 30 grams of flaxseed, a third received a low-fat diet and the fourth ate a low-fat diet supplemented with flaxseed. Those who were fed a flaxseed-supplemented diet showed significantly reduced proliferation of cancer cells than those who got no flaxseed. As an added benefit, those who ate the low-fat diet supplemented with flaxseed showed a significant reduction in cholesterol levels. Researchers published their findings in the December 2008 issue of “Cancer Epidemiology, Biomarkers & Prevention.”
Practitioners of traditional medicine have long used flaxseed for its laxative effects, which the University of Maryland Medical Center singles out as one of flaxseed’s several benefits for digestive health. Flaxseed is rich in dietary fiber and mucilage, a gummy substance that expands when it comes into contact with liquid. Together, flaxseed’s insoluble fiber and mucilage add bulk to the stool, which facilitates its passage through your gastrointestinal tract. Despite the many benefits of dietary fiber, the Harvard School of Public Health estimates that the average daily intake of fiber by Americans is 15 grams. That is sharply lower than the daily value of 25 grams established by the Food and Drug Administration.
- University of Maryland Medical Center: Flaxseed
- The Canadian Journal of Cardiology: The Cardiovascular Effects of Flaxseed and Its Omega-3 Fatty Acid, Alpha-Linolenic Acid
- Skin Pharmacology and Physiology: Supplementation of Flaxseed Oil Diminishes Skin Sensitivity and Improves Skin Barrier Function and Condition
- Cancer Epidemiology, Biomarkers & Prevention: Flaxseed Supplementation (Not Dietary Fat Restriction) Reduces Prostate Cancer Proliferation Rates in Men Presurgery
- Harvard School of Public Health: The Nutrition Source: Fiber: Start Roughing It!
- FDA: Calculate the Percent Daily Value for the Appropriate Nutrients
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