Flax, long known for its use in linen clothing, now is gaining attention as a health food.
Flaxseed is an ancient, blue-flowering crop cultivated extensively in Canada. The flax plant produces a fiber from which linen is woven and an edible seed from which oil can be extracted. Over the past several years, it has been discovered that the edible form of the oil and the seed contain a wealth of healthful substances, including fiber, heart healthy omega-3 fatty acids and plant chemicals called lignans, which may help reduce the risk for certain types of cancer.
Full of fiber: The seed of the flax plant contains significant amounts of soluble fiber, mainly in the form of mucilage gum. Similar to the fiber found in oat bran and pectin, research has shown mucilage gum helps lower blood levels of cholesterol.
Contains heart-healthy fats: As excellent sources of alpha-linolenic acid, an omega-3 fatty acid, flaxseed and flaxseed oil currently are being investigated for possible heart-health benefits. Research has suggested that the omega-3 fatty acids found in fish oil are beneficial in reducing total cholesterol, LDL-cholesterol (the so-called bad cholesterol) and triglyceride levels. Decreased levels of these three lipids have been associated with decreased risk for cardiovascular disease. Although the alpha-linolenic acid found in flaxseed oil is not identical to the omega-3 fatty acids found in fish oil, the body does convert alpha-linolenic acid from flaxseed oil to the same type of omega-3 fatty acids found in fish oil.
Lowers cancer risk: In animal studies, diets rich in flaxseed have been associated with reducing the size and aggressiveness of both mammary and prostate cancerous tumors. In addition, a 2001 study conducted by Duke University found a low-fat diet containing 30 grams of flaxseed per day to be associated with slower tumor growth in 25 men with prostate cancer. The plant chemicals – called lignans found in flaxseed are believed to be responsible. Lignans are plant estrogens thought to work against estrogen and testosterone produced by the body, which in some cases can stimulate certain cancers to grow.
If you are interested in including flaxseed or flaxseed oil in your diet, keep the following in mind:
- Because it is high in fiber, add flaxseed to your diet gradually and drink plenty of water.
- Flax seeds, as well as flaxseed flour and oil, can turn rancid quickly if stored at warm room temperatures. It’s best to buy them in quantities that you will use within a few months and to store flaxseed flour and oil in the refrigerator once opened.
- The seeds of the flax plant have a hard outer coating and, unless ground or thoroughly chewed, they pass through the body undigested. Also, the raw seeds do contain small amounts of cyanogenic glucosides, which can be toxic if consumed in large quantities. Cooking seems to break down the toxic components.
- Pregnant women should be careful to not eat too much flaxseed; in animal studies, flaxseed given to pregnant rats lowered the birth weight of their male offspring.
- Breast cancer patients taking the drug tamoxifen should consult their doctor before eating flaxseed.