Omega-3 fatty acids are essential nutrients that must be consumed in the diet because the body can't manufacture them by itself. The most beneficial form of omega-3 is eicosapentaenoic acid, or EPA. This is found in coldwater fish, and since not everyone has easy access to that type of fish, the body has developed a way to convert another omega-3, alpha-linolenic acid, or APA, into EPA. Sufficient APA can be supplied by eating several servings of some common vegetables each day.
Dark, Green Leafy Vegetables
The vegetables that contain the highest amounts of ALA, according to Tufts University researchers, include kale, mustard greens and spinach. Arugula and red tipped lettuce come close, and provide a spicy accent in salads.
Mint and watercress can further expand the choice of high-ALA salad greens, according to Australian nutritionists C. Pereira and A.J. Sinclair, who wrote about these herbs in the July 2001 issue of the "International Journal of Vitamin Nutritional Research."
All herbs contain ALA, which holds up well in cooking. Adding fresh basil and arugula to spaghetti squash can make this pasta-substitute a very healthy dish, as can a stir-fry of kale and crushed walnuts, one of the best plant sources of omega-3.
Winter Squash
Normally only 2 percent of ALA is converted to EPA, and it is EPA that has been found to protect the body from cardiovascular disease, diabetes, depression and some forms of cancer. This means that non-fish eaters need to consume large amounts of vegetables in their daily diet, and adding variety to menus makes meeting this requirement easier.
The U.S. Department of Agriculture analyzed the omega-3 content of the squash family and found that the winter squashes had three times higher levels of ALA than summer varieties.
All forms of winter squash are good source of ALA, including hubbard, spaghetti, acorn and butternut. Alos, because winter squashes also act as a appetite-satisfying starch in a meal, they can serve as a nutritious substitute for pasta, white rice or french fries.
Cruciferous Vegetables
Cruciferous vegetables including cauliflower, broccoli, cabbages and Brussels sprouts all contain ALA-omega-3 fatty acids. The Harvard School of Public Health reports that ALA in these vitamin-rich vegetables is more likely convert to EPA more readily when fish is not available.
In July 2004, writing in the the "European Journal of Clinical Nutrition," researchers from the Netherlands reported finding that the ALA in these vegetables serves a critical function apart from its ability to convert to EPA. When ALA levels were increased six-fold in the diet of the women studied, the level of a chemical marker for inflammation, associated with heart attack risk, significantly declined. Especially for women at risk of heart attacks, such as those who are challenged by obesity, diabetes or high levels of the dangerous low-density lipoprotein, LDL-cholesterol these findings are particularly significant.
Adding a heaping serving of raw broccoli and cauliflower with a yogurt and dill dressing to the menu on odd days and serving Brussels spouts or steamed cabbage on even days makes hearty-healthy sense.
References
- Tufts Univeristy School of Medicine, Infection and Nutrition Unit: Omega-3 Fatty Acids
- "International Journal for Vitamin and Nutrition Research";The Alpha-Linolenic Acid Content of Green Vegetables Commonly Available in Australia; C. Pereiera and A.J. Sinclair; July 2001
- "European Journal of Clinical Nutrition"; Increased alpha-linolenic acid intake lowers C-reactive protein, but has no effect on markers of atherosclerosis; W.J. Berlmelmans et al; July 2004
- U.S. Food and Drug Administration: Nutrient Data Laboratory
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