The Benefits of Flaxseed
Is flaxseed the new wonder food? Preliminary studies show that it may help fight heart disease, diabetes and breast cancer.By Elaine Magee, MPH, RDFROM THE WEBMD ARCHIVES
Some call it one of the most powerful plant foods on the planet. There’s some evidence it may help reduce your risk of heart disease, cancer, stroke, and diabetes. That’s quite a tall order for a tiny seed that’s been around for centuries.
Flaxseed was cultivated in Babylon as early as 3000 BC. In the 8th century, King Charlemagne believed so strongly in the health benefits of flaxseed that he passed laws requiring his subjects to consume it. Now, thirteen centuries later, some experts say we have preliminary research to back up what Charlemagne suspected.
Flaxseed is found in all kinds of today’s foods from crackers to frozen waffles to oatmeal. The Flax Council estimates close to 300 new flax-based products were launched in the U.S. and Canada in 2010 alone. Not only has consumer demand for flaxseed grown, agricultural use has also increased. Flaxseed is what’s used to feed all those chickens that are laying eggs with higher levels of omega-3 fatty acids.
Although flaxseed contains all sorts of healthy components, it owes its primary healthy reputation to three of them:
- Omega-3 essential fatty acids, “good” fats that have been shown to have heart-healthy effects. Each tablespoon of ground flaxseed contains about 1.8 grams of plant omega-3s.
- Lignans, which have both plant estrogen and antioxidant qualities. Flaxseed contains 75 to 800 times more lignans than other plant foods.
- Fiber. Flaxseed contains both the soluble and insoluble types.
The Health Benefits of Flax
Although Lilian Thompson, PhD, an internationally known flaxseed researcher from the University of Toronto, says she wouldn’t call any of the health benefits of flax “conclusively established,” research indicates that flax may reduce risks of certain cancers as well as cardiovascular disease and lung disease.
Recent studies have suggested that flaxseed may have a protective effect against breast cancer, prostate cancer, and colon cancer. At least two of the components in flaxseed seem to contribute, says Kelley C. Fitzpatrick, director of health and nutrition with the Flax Council of Canada.
In animal studies, the plant omega-3 fatty acid found in flaxseed, called ALA, inhibited tumor incidence and growth.
The lignans in flaxseed may provide some protection against cancers that are sensitive to hormones without interfering with the breast cancer drug tamoxifen. Thompson says some studies have suggested that exposure to lignans during adolescence helps reduce the risk of breast cancer and may also increase the survival of breast cancer patients.
Lignans may help protect against cancer by blocking enzymes that are involved in hormone metabolism and interfering with the growth and spread of tumor cells.
Some of the other components in flaxseed also have antioxidant properties, which may contribute to protection against cancer and heart disease.
Research suggests that plant omega-3s help the cardiovascular system through several different mechanisms, including anti-inflammatory action and normalizing the heartbeat. Fitzpatrick says new research also suggests significant blood pressure-lowering effects of flaxseed. Those effects may be due to both the omega-3 fatty acids as well as the amino acid groups found in flaxseed.
Several studies have suggested that diets rich in flaxseed omega-3s help prevent hardening of the arteries and keep plaque from being deposited in the arteries partly by keeping white blood cells from sticking to the blood vessels’ inner linings.
“Lignans in flaxseed have been shown to reduce atherosclerotic plaque buildup by up to 75%,” Fitzpatrick says.
Because plant omega-3s may also play a role in maintaining the heart’s natural rhythm, they may be useful in treating arrhythmia (irregular heartbeat) and heart failure. More research is needed on this.
Eating flaxseed daily may also help your cholesterol levels. The level of LDL or “bad” cholesterol in the bloodstream has been linked to an increased risk of heart disease, obesity, diabetes, and metabolic syndrome. A study of menopausal women showed a decrease in LDL level after the women ate 4 tablespoons of ground flaxseed each day for a year. Fitzpatrick says the cholesterol-lowering effects of flaxseed are the result of the combined benefits of the omega-3 ALA, fiber, and lignans.
Preliminary research also suggests that daily intake of the lignans in flaxseed may modestly improve blood sugar (as measured by hemoglobin A1c blood tests in adults with type 2 diabetes).
Two components in flaxseed, ALA and lignans, may reduce the inflammation that accompanies certain illnesses (such as Parkinson’s disease and asthma) by helping block the release of certain pro-inflammatory agents, Fitzpatrick says.
ALA has been shown to decrease inflammatory reactions in humans. And studies in animals have found that lignans can decrease levels of several pro-inflammatory agents.
Reducing inflammation associated with plaque buildup in the arteries may be another way flaxseed helps prevent heart attack and strokes.
One study of menopausal women, published in 2007, reported that 2 tablespoons of ground flaxseed mixed into cereal, juice, or yogurt twice a day cut their hot flashes in half. The intensity of their hot flashes also dropped by 57%. The women noticed a difference after taking the daily flaxseed for just one week and achieved the maximum benefit within two weeks.
But another study reported no significant reduction in hot flashes between postmenopausal women and breast cancer patients eating a bar containing 410 milligrams of phytoestrogens from ground flaxseed and women eating a placebo bar.
The results, says Thompson, are consistent with other studies that have shown no siginifcant difference in the effect on hot flashes between flaxseed and placebo
Flaxseed Isn’t a Magic Bullet
It’s tempting to think of flaxseed as a super food because of its many potential health benefits. But keep in mind there is no magic food or nutrient that guarantees improved health.
What matters is consistently making great dietary choices as part of an overall healthy lifestyle.
Who Shouldn’t Use Flaxseed?
Until more is known, Thompson says, pregnant women and possibly breastfeeding mothers should not supplement their diets with ground flaxseed.
“Our own animal studies showed that flaxseed exposure during these stages may be protective against breast cancer in the offspring. But a study of another investigator showed the opposite effect,” Thompson says.
Tips for Using Flaxseed
Many experts believe it’s better to consume flaxseed than flax oil (which contains just part of the seed) so you get all the components. But stay tuned as researchers continue to investigate.
Thompson says, “Ground flaxseed, in general, is a great first choice, but there may be specific situations where flax oil or the lignans (taken in amounts naturally found in flaxseed) might be as good.”
How much flaxseed do you need? The optimum dose to obtain health benefits is not yet known. But 1 to 2 tablespoons of ground flaxseed a day is currently the suggested dose, according to the Flax Council of Canada.
Here are more tips for using, buying, and storing flaxseed:
- Buy it ground or grind it yourself. Flaxseed, when eaten whole, is more likely to pass through the intestinal tract undigested, which means your body doesn’t get all the healthful components. If you want to grind flaxseed yourself, those little electric coffee grinders seem to work best.
- Milled = ground = flax meal. Don’t be confused by the different product names for ground flaxseed. Milled or ground flaxseed is the same thing as flax meal.
- Buy either brown or golden flaxseed. Golden flaxseed is easier on the eyes, but brown flaxseed is easier to find in most supermarkets. There is very little difference nutritionally between the two, so the choice is up to you.
- Find it in stores or on the Internet. Many supermarket chains now carry ground flaxseed (or flax meal). It’s usually in the flour or “grain” aisle or the whole-grain cereal section and is often sold in 1-pound bags. You can also find it in health food stores or order it on various web sites.
- Check the product label. When buying products containing flaxseed, check the label to make sure ground flaxseed, not whole flaxseed, was added. Flaxseed is a featured ingredient in cereals, pasta, whole grain breads and crackers, energy bars, meatless meal products, and snack foods.
- Add flaxseed to a food you habitually eat. Every time you have a certain food, like oatmeal, smoothies, soup, or yogurt, stir in a couple tablespoons of ground flaxseed. Soon it will be a habit and you won’t have to think about it, you’ll just do it.
- Hide flaxseed in dark, moist dishes. The dishes that hide flaxseed the best are dark sauces or meat mixtures. No one tends to notice flaxseed when it’s stirred into enchilada casserole, chicken parmesan, chili, beef stew, meatloaf, or meatballs. For a 4-serving casserole, you can usually get away with adding 2 to 4 tablespoons of ground flaxseed. For a dish serving 6 to 8, use 4 to 8 tablespoons.
- Use it in baking. Substitute ground flaxseed for part of the flour in recipes for quick breads, muffins, rolls, bread, bagels, pancakes, and waffles. Try replacing 1/4 to 1/2 cup of the flour with ground flaxseed if the recipe calls for 2 or more cups of flour.
- Keep it in the freezer. The best place to store ground flaxseed is the freezer. Freeze pre-ground flaxseed in the bag you bought it in or in a plastic sealable bag if you ground it yourself. The freezer will keep the ground flax from oxidizing and losing its nutritional potency.
- Whole flaxseed keeps longer. The outside shell in whole flaxseed appears to keep the fatty acids inside well protected. It’s a good idea to keep your whole flaxseed in a dark, cool place until you grind it. But as long as it is dry and of good quality, whole flaxseed can be stored at room temperature for up to a year.
Ready to try flaxseed? Here’s a recipe to get you started from The Flax Cookbook: Recipes and Strategies for Getting The Most from The Most Powerful Plant on the Planet.
Fruity Flaxseed Muffins
These moist and high-flavor flax muffins are not only good for you, but they taste great too.
1/2 cup crushed pineapple with juice, canned
1/2 cup finely chopped apples (with peel)
2 tablespoons canola oil
1 large egg, higher omega-3 if available, beaten lightly
2 egg whites (or 1/4 cup egg substitute)
1 cup fat free sour cream
1/4 cup dark molasses
1/2 cup raisins, currants (or any other dried fruit, chopped)
1 1/4 cup unbleached white flour
1/2 cup whole-wheat flour
1 teaspoon baking powder
1 teaspoon baking soda
1/4 teaspoon salt
3/4 cup ground flaxseed
- Preheat oven to 400 degrees. Line muffin pan with paper or foil liners. Coat inside of liners with a quick squirt of canola cooking spray.
- In large mixing bowl, beat together the pineapple with juice, apples, canola oil, egg, egg whites or egg substitute, sour cream, and molasses until mixture is light and fluffy. Stir in raisins or dried fruit.
- In medium bowl, whisk together flours, baking powder, baking soda, salt, and flaxseed.
- Add flaxseed mixture to sour cream mixture, beating on low speed just until combined (batter will be a little lumpy). Spoon batter by 1/4 cupful into prepared muffin pan.
- Bake in center of preheated oven for about 20 minutes or until muffins are golden brown and springy to the touch.
Yield: 12 muffins
Nutritional Analysis: Per muffin: 194 calories, 5 g protein, 31 g carbohydrate, 5.5 g fat, .8 g saturated fat, 2.1 g monounsaturated fat, 2.6 g polyunsaturated fat, 20 mg cholesterol, 4.5 g fiber, 224 mg sodium, 1.7 g omega-3 fatty acids. Calories from fat: 28%.
Recipe reprinted with permission.
Elaine Magee, MPH, RD, is the author of numerous books on nutrition and health. Her opinions and conclusions are her own
Side Effects of Flaxseed
When taken by mouth: Flaxseed is LIKELY SAFE for most adults when taken by mouth appropriately. Adding flaxseed to the diet might increase the number of bowel movements each day. It might also cause gastrointestinal (GI) side effects such as bloating, gas, abdominal pain, constipation, diarrhea, stomachache, and nausea. Higher doses are likely to cause more GI side effects.
There is some concern that taking large amounts of flaxseed could block the intestines due to the bulk-forming laxative effects of flaxseed. Flaxseed should be taken with plenty of water to prevent this from happening.
Taking flaxseed extracts that contain lignans in concentrated form is POSSIBLY SAFE. Lignans are the chemicals in flaxseed that are thought to be responsible for many of the effects. Some clinical research shows that a specific flaxseed lignan extract (Flax Essence, Jarrow Formulas) can be safely used for up to 12 weeks. Other research shows that other flaxseed extracts can be used safely for up to 6 months.
Products that contain partially defatted flaxseed, which is flaxseed with less alpha-linolenic acid content, are available. Some men choose these products because they have heard that alpha-linolenic acid might raise their risk of getting prostate cancer. It’s important to remember that the source of the alpha-linolenic acid is key. Alpha-linolenic acid from dairy and meat sources has been positively associated with prostate cancer. However, alpha-linolenic acid from plant sources, such as flaxseed, does not seem to affect prostate cancer risk. Men should not worry about getting alpha-linoleic acid from flaxseed. On the other hand, there is a concern that partially defatted flaxseed might raise triglyceride levels too much. Triglycerides are a type of blood fat.