Recipe: Flax Spread
Sometimes we scour the planet for the most exotic, expensive remedies while ignoring more affordable ones right at hand. So it is with flaxseed. Few eat this nutty-tasting food, yet it costs less than two dollars a pound. More importantly, it helps prevent cancer, assuages menopausal symptoms, and appears to improve cardiovascular health. And, once you get the hang of it, incorporating flaxseed or its oil into your daily diet is easy.
An Ancient Medicine
Botanists know flax as Linum usitatissimum. The rest of us know it as linseed, the source of linen fiber, linseed oil, and linoleum. People used to enjoy eating the seeds. In ancient Greece and Rome, for example, flax was a common ingredient in breads. These people also recognized flax’s medicinal potential. In the first century, the Roman scholar and naturalist Pliny, known as “the Elder,” cited thirty remedies using flax, and many of them match today’s scientific knowledge. As Pliny noted, flax makes an excellent poultice, throat-soothing brew, and mild laxative.
For the nearly two thousand years since Pliny’s time, flax has remained a favorite folk medicine. But, until recently, only a handful of health-conscious cooks, some Scandinavian bakers, and most Ethiopians have eaten flax. That may soon change.
A Modern Discovery: Breast Cancer Prevention
About a decade ago, several research teams, encouraged by news that flaxseed behaved like a weak form of estrogen, wondered whether flax might inhibit breast cancer. Although some human estrogens can promote breast cancer, estrogenlike compounds found in plants—called phytoestrogens—may actually block this effect. This appears to be the case for soybeans, whose phytoestrogens may contribute to the low rate of breast cancer among Asians who eat a soy-rich diet.
To test the flax hypothesis, the researchers studied laboratory rats. In one set of experiments, they fed three groups of rats a high-fat diet, known to contribute to some cases of breast cancer. One group’s diet contained 5 percent flaxseed meal, a second group’s diet contained 10 percent flaxseed meal, and the third group received just the high-fat diet and no flax. Both flax-fed groups showed vastly reduced levels of the markers of the early stages of breast cancer, the researchers reported, and, as compared to the control group, the rats eating the diet with 5 percent flax fared best.
In another experiment, the researchers treated rats with a high-fat diet and chemicals that cause breast cancer. After tumors developed, the researchers divided the rats into five groups: Two received flaxseed meal, one group received flaxseed oil, a fourth group received a flax compound known as SDG, and a control group didn’t receive any supplement treatments. After seven weeks, all four of the treated groups showed at least a 50 percent reduction in tumor size compared to the control group.
Another team of scientists tested the flax derivative enterolactone on human breast cancer cells, which multiply when exposed to the human estrogen estradiol. When the researchers added enterolactone alone to the culture, it behaved like an estrogen and stimulated cancer cell growth. But when they treated the cells with both enterolactone and estradiol, the enterolactone inhibited the cells’ growth, much as tamoxifen does in human patients.
Further Flax Research: Colon, Prostate Cancer Protection
The results of a few experiments suggest that flax may also inhibit the spread of melanoma cells and the development of colon and prostate cancers. In one experiment, rats treated with a chemical that triggers colon cancer developed fewer aberrant crypts (a sign of colon cancer) when their diet was later supplemented with 2.5 percent or 5 percent flaxseed than rats who didn’t receive any flax supplements. Other research has shown that a flax-derived compound inhibits an enzyme that can promote the growth of hormone-dependent prostate tumors.
Researchers speculate that flax may help prevent cancer in several ways. Some forms of cancer, especially estrogen-dependent types, are almost certainly inhibited by the seeds’ phytoestrogens. These phytoestrogens are also strong antioxidants, so their cancer-prevention abilities may result from a second activity —preventing free-radical damage to cell membranes and genes. And flax contains alpha-linolenic acid, which may block the production of a protein called TNF (tumor necrosis factor) that helps create the blood vessels that tumors need to grow.
Help For The Heart?
Beyond cancer prevention, flaxseed and its oil appear to improve cardiovascular health, as illustrated in two studies of healthy young men. In one, the men ate 50 g of flaxseed daily (about 5 percent of their day’s calories). After four weeks, their LDL cholesterol fell by 8 percent. Men in a second study ate 40 g (about three tablespoons) of flaxseed oil for twenty-three days. The flax treatment reduced the men’s platelet aggregation potential; although platelets are needed for normal blood clotting, they also are involved in creating atherosclerotic plaques, which can lead to heart disease.
And for women, flaxseed may help offset hot flashes during menopause. One study has shown that enterolactone can substantially decrease hot-flash frequency, and anecdotal reports from menopausal women back this up. In fact, many menopausal women, concerned that standard hormone replacement therapy may stimulate breast cancer, are turning to flax and soy for a more natural food-based therapy.
Getting Flax Into Your Diet
Is a diet of 5 percent flaxseed safe? How does such a diet taste?
So far, investigators have discovered no detrimental effects in healthy volunteers who ate one or two muffins containing 25 g to 50 g flaxseed (about three to five tablespoons whole or four to seven tablespoons ground) daily for a month. This equals about 90 to 180 calories, or about 5 percent of an average adult’s caloric intake. Note, however, that the effects of phytoestrogens on pregnancy and lactation haven’t been exhaustively studied, so if you’re nursing, pregnant, or trying to become pregnant, talk to your health-care provider before regularly eating this amount of flax.
Muffins containing 25 g to 50 g of flax can, however, taste unpleasantly gummy. So you might consider integrating small amounts of flax into a variety of nutritious foods and consuming it, bit by bit, disguised, throughout the day. Flaxseed absorbs lots of water, so drink plenty of liquid when eating flax-containing foods.
Whole flaxseed is available in most natural food stores. Don’t buy pre-ground seeds because as soon as the seeds shatter, the highly unsaturated oil inside oxidizes and spoils rapidly—within days, if the weather is hot. Store the seeds in the refrigerator and in an air-tight container to be safe.
It’s easy and quick to grind the amount of flaxseed you need in an electric coffee mill. If you use the mill for coffee, too, grind a tablespoon of rice between each use to avoid contaminating the flavor of either the flax or the coffee.
Whole flaxseed, with its mild earthy-nutty taste, deserves a place alongside your kitchen staples, ready to sprinkle over cereal, swirl into hot oatmeal, whip into muffins and batters, knead into breads, and drizzle into soups. You can also use it as a substitute for meat, junk food, or high-fat spreads and oils.
• To thicken hot soups, add one to two tablespoons whole seeds per cup of liquid about five to ten minutes before serving. Try the smaller quantity first and add more the next time if you like the effect.
• To add nutty flavor and crunch to bread sticks, bagels, or crackers, add two tablespoons whole seeds per cup of flour, and impress the tops with more seeds before baking.
• To enrich oatmeal or pancakes, add up to one-fourth cup whole seeds per cup of oats or flour.
• To enliven granola or commercial dry cereal, add one to three tablespoons per cup of dry mix.
• Most recipes for breads, rolls, and muffins benefit from the addition of up to one-third cup seeds for every cup of flour.
Ground flaxseed has a stronger aroma than the whole seeds. It also produces a heavier bread. I prefer to use the ground form in dark whole-grain breads, buckwheat pancakes, and fruit-flavored muffins. But instead of adding ground seeds, try substituting a portion for an equal amount of flour. Start by replacing one-fourth cup of the flour with ground seeds, adding an extra tablespoon of liquid if the batter or dough is too thick.
Because heat accelerates the oxidation of flaxseed oil, I generally bake flax breads at no higher than 350°F. 8
Flax Fat—The Good Kind
• Allman, M. A., et al. “Supplementation with flaxseed oil versus sunflowerseed oil in healthy young men consuming a low fat diet: Effects on platelet composition and function.” European Journal of Clinical Nutrition 1995, 49(3):169–178.
• Caughey, G. E., et al. “The effect on human tumor necrosis factor alpha and interleukin 1 beta production on diets enriched in n-3 fatty acids from vegetable oil or fish oil.” American Journal of Clinical Nutrition 1996, 63(1): 116–122.
• Cunnane, S. C. “Nutritional attributes of traditional flaxseed in healthy–young adults.” American Journal of Clinical Nutrition 1995, 61(1):62–68.
• Evans, B. A., et al. “Inhibition of 5 alpha-reductase in genital fibroblasts and prostate tissue by dietary lignans and isoflavonoids.” Journal of Endocrinology 1995, 147(2):295–302.
• Jenab, M., and L. U. Thompson. “The influence of flaxseed and lignans on colon carcinogenesis and beta-glucuronidase.” Carcinogenesis 1996, 17(6):1343–1348.
• Mousavi, Y., and H. Adlercruetz. “Enterolactone and estradiol inhibit each other’s proliferative effect on MCF-7 breast cancer cells in culture.” Journal of Steroid Biochemistry and Molecular Biology 1992, 41(3-8): 615–619.
• Murkies, A. L., et al. “Dietary flour supplementation decreases post-menopausal hot flushes: Effect of soy and wheat.” Maturitas 1995, 21(3):189–195.
• Serraino, M., and L. U. Thompson. “The effect of flaxseed supplementation on early risk markers for mammary carcinogenesis.” Cancer Letters 1991, 60(2):135–142.
• Thompson, L. U., et al. “Flaxseed and its lignan and oil components reduce mammary tumor growth at a late stage of carcinogenesis.” Carcinogenesis 1996, 17(6):1373–1376.
• Yan, L., et al. “Dietary flaxseed supplementation and experimental metastasis of melanoma cells in mice.” Cancer Letters 1998, 124(2):181–186.
Cornelia Carlson holds a doctorate in biochemistry and is an avid grower and user of herbs. She writes from her home in Southern California.