Fish, Canola Oil, and Walnuts Tackle Allergens
Children require two kinds of polyunsaturated fats, omega-6 and omega-3, for the best growth and development. Corn, sunflower, and safflower oils, used in commercial cookies, chips, cakes, and salad dressings, are rich in omega-6s. Fish, canola oil, and walnuts supply the most omega-3s. When in balance, these two fats help kids' immune systems fight off disease. The best ratio of omega-6s to omega-3s is 2.5 to 1, according to the USDA.
Unfortunately, USDA research shows that the typical American diet has about 10 teaspoons of omega-6 for every one teaspoon of omega-3, which is more than four times the optimum level. The result: Too much omega-6 prompts the immune system to overproduce chemicals called cytokines that inflame airways and make lung tissue very sensitive to irritants like dust, dander, and pollution. "Omega-3-rich fish oil dampens cytokine production and calms airways," explains Robert F. Grimble, Ph.D., professor of nutrition at the University of Southampton in England.
An Australian study of 574 children found that kids who ate fresh fish -- particularly the fatty kind that is high in omega-3s -- were 75% less likely to be asthmatic. In the ISAAC study, children in countries with the highest seafood consumption were least likely to have asthma. Several additional reports, including Dr. Broughton's, suggest that fish oil supplements improve asthma symptoms in at least half of sufferers.
While omega-3s seem to prevent asthma, new research suggests that high levels of omega-6s increase its likelihood. An Australian study examined risk factors for asthma in 974 children 3 to 5 years old and found that those who ate a lot of omega-6 fatty acids from margarine and vegetable oil were twice as likely to develop asthma as children whose fat usually came from canola oil, olive oil, or even butter. "The high intake of these polyunsaturated fats may account for 17% of the asthma cases in the study," says Michelle Haby, Ph.D., a researcher at Royal Children's Hospital in Melbourne.
Breath-Saving Strategy: Serve more foods rich in omega-3s and fewer loaded with omega-6s. Here, four ways to strike a better balance:
Hook 'em on fish. Twice a week, replace a serving of meat with fish for kids over age 1. (Delay to age 3 if your family has a history of food allergies.) Fish like salmon, herring, and anchovies pack the most omega-3s. But white tuna in water has an ample amount -- in fact, any kind of seafood has more omega-3s than meat.