The Benefits of Flaxseed

Is flaxseed the new wonder food? Preliminary studies show that flaxseed may help fight everything from heart disease and diabetes to even breast cancer.

By Carol Sorgen
WebMD Features Reviewed By Michael Smith, MD

Flaxseed may be on everyone's lips -- and in everyone's cereal -- but this new darling of the plant world has been around for more than 4,000 years, known even in the days of Hippocrates for its healthful benefits.

Flaxseed has been a part of human and animal diets for thousands of years in Asia, Europe, and Africa, and more recently in North America and Australia, says Kaye Effertz, executive director of AmeriFlax, a trade promotion group representing U.S. flaxseed producers. As flax gained popularity for its industrial uses, however, its popularity as a food product waned, but it never lost its nutritional value. "Today flax is experiencing a renaissance among nutritionists, the health conscious public, food processors, and chefs alike," says Effertz.

The reason for the increasing interest in flaxseed is its apparent benefits for a host of medical conditions, says Roberta Lee, MD, medical director of the Center for Health and Healing at Beth Israel Deaconess Medical Center in New York.

Flaxseed is very high in omega-3 essential fatty acids, Lee explains. It's the omega 3s -- "good" fats -- that researchers are looking at in terms of their possible effects on lowering cholesterol, stabilizing blood sugar, lowering the risk of breast, prostate, and colon cancers, and reducing the inflammation of arthritis, as well as the inflammation that accompanies certain illnesses such as Parkinson's disease and asthma.

In addition to the omega-3s, the remaining two components of flaxseed -- lignans and fiber -- are being studied for their health benefits as well, says Diane Morris, PhD, RD, spokesperson for the Flax Council of Canada. Lignans, for example, act as both phytoestrogens and antioxidants, while the fiber contained in the flaxseed is of both the soluble and insoluble type. "Flax is an interesting mixture of nutrients and other components," says Morris.

Though studies conducted to date have been limited in scope and small in nature, their results are promising, says Morris. In a small Canadian study of 39 women, for example, researchers from the University of Toronto found that flaxseed may boost conventional treatment for breast cancer. In the study, reported in the American Institute for Cancer Research Newsletter in 1998, postmenopausal women with breast cancer ate either a plain muffin or a muffin containing 25 grams of flaxseed oil every day for approximately five-and-a-half weeks. Of the 29 out of the 39 women who ate both muffins, researchers found reductions in the growth of their tumors.

These results were encouraging, says Morris, but she adds, "It's just one study." The favorable results of that study, however, are leading to others. At the John Wayne Cancer Institute in Santa Monica, Calif., for example, investigators are also looking into the effect of essential fatty acids on breast cancer, says Rachel Beller, MS, RD, director of the Brander Nutritional Oncology Counseling and Research Program. But here, too, says Beller, it's too soon to have any conclusive findings.

In addition to research on breast cancer, Morris says, other studies are looking at heart disease, blood pressure, diabetes, menopause, osteoporosis, and inflammatory bowel disease, to name just a few.

Yet another study has found that omega-3 fatty acids, and by extension, flaxseed, can reduce the risk of macular degeneration -- an eye disease that destroys vision by damaging nerve cells in the eye. The results of a Harvard study, published in August 2001 in the Archives of Ophthalmology, showed that people with a high intake of omega-6 (vegetable oils) were more likely to develop macular degeneration, while those with a combination of lower omega-6 intake and high omega-3 intake were less likely to have the disease.

"Flaxseed is the best source of omega-3 fatty acids," says Lylas G. Mogk, MD, director of the Henry Ford Visual Rehabilitation and Research Center in Detroit, chairman of the Vision Rehabilitation Committee of the American Academy of Ophthalmology, and co-author of Macular Degeneration: The Complete Guide to Saving and Maximizing Your Sight.

Flaxseed is also good for combating dry eyes, a very common problem, says Mogk, probably because of our poor omega-3 intake. "Dry eyes are usually the result of an insufficient outer oil layer in the tear film, so the water in the tears doesn't have anything to keep it from evaporating," she says. Omega-3 fatty acids help the oil glands produce the proper consistency of oil so it will flow from the oil glands and coat the surface of the eye.

Mogk recommends that her patients take a tablespoon a day of flaxseed oil. "I think all adults should do this," she says, "and most certainly those at high risk for macular degeneration (which includes those between the ages of 65 and 74, those who have a family member with the disease, women, and whites).

Flaxseed is available in supermarkets and health food stores and comes in whole seeds, ground seeds, or oil. Most nutrition experts recommend the ground seeds, which have "all the goodies," says Morris -- the fiber, the lignans, and the essential fatty acids. Whole seeds will pass through your system undigested, she says, while the oil lacks the fiber, which, if nothing else, will help alleviate any problems of constipation. (Some patients with diverticulosis, however, find the ground flaxseed too irritating; for those people, says Lee, the flaxseed oil is a better choice.)

Ninety-six percent of the flaxseed grown in the U.S. is grown in North Dakota because of its cooler climate and wide open spaces, says Kaye Effertz; for those same reasons, Canada is also a top grower of flaxseed. Flaxseed comes in two colors -- reddish brown and golden brown. The color makes no difference when it comes to nutritional value.

Rachel Beller recommends buying ground flaxseed in vacuum-packed bags. Most people refrigerate their flaxseed, but Morris says that's not a necessity (even though she does it herself). Whole seeds will last from 10-12 months, she says, while ground flax has a shelf life of about four months, even out of the refrigerator.

The recommended daily amount of flaxseed is approximately 1-2 tablespoons of ground flaxseed, or 1 teaspoon of flax oil (which is best used cold, perhaps mixed in a vinaigrette salad dressing). Morris' favorite way to get her flaxseed is to mix a tablespoon of the ground seeds with 2 tablespoons of honey, and then spread the mixture on toast. "It has a nutty flavor," she says, "and is a great alternative to buttering your toast."

Texas nutritionist Natalie Elliott offers these additional suggestions for adding flax to your diet:

Sprinkle ground flax on cereal, yogurt, or salads.
Mix flax into meatloaf or meatballs.
Add ground flax to pancake, muffin, or cookie batter, or other baked goods such as pie crust.
Coat fish or homemade chicken nuggets in ground flaxseed and oven fry.
Toss salads with flax oil and vinegar.

Or try one of her favorites, "Nat's Flax Snacks":

SOURCES: Kaye Effertz, executive director, AmeriFlax, Mandan, N.D. Roberta Lee, MD, medical director, Center for Health and Healing, Beth Israel Deaconess Medical Center, New York. Diane Morris, PhD, RD, spokesperson for Flax Council of Canada, Toronto. Rachel Beller, MS, RD, director, Brander Nutritional Oncology Counseling and Research Program, John Wayne Cancer Institute, Santa Monica, Calif. Archives of Ophthalmology, August 2001. "Research Update: Flaxseed Shows Promise Against Breast Cancer," American Institute for Cancer Research Newsletter 59, Winter 1998. Natalie Elliott, co-owner, Brain Waves Music and Wellness Center, Austin, Texas.