News Coverage
No Fish on Your Dish? No Problem
Published August 18, 2003
Eating fish -- particularly sardines and salmon -- remains the most efficient way to boost levels of the healthy fat known as omega-3 fatty acids.
Fish and seafood come up winners because they not only provide both types of essential omega-3 fatty acids (what experts call the long and the short forms) but also have what many scientists believe are healthy ratios to other fats, especially omega-6 fatty acids.
Scientists still debate what the optimal ratio is. But humans appear to have evolved eating a diet that was closer to equal amounts of omega-3s and omega-6s than is typical now in the United States. Today, most Americans consume about 10 times more omega-6 fatty acids than omega-3s.
"A good ratio is anything less than four to one, omega-6s to omega-3s," says Artemis Simopoulos, director of the nonprofit Center for Genetics, Nutrition and Health in the District.
Okay, but what if you don't like fish? Or what if you worry about contaminants in seafood? A recent study by another nonprofit, the Environmental Working Group, found that farm-raised salmon had appreciably greater amounts of polychlorinated biphenyls (PCBs) than wild salmon. (PCBs are a known cancer-causing agent in animals and a suspected one in humans.) And because of concerns about the level of mercury in some species of fish, the Food and Drug Administration (FDA) advises children, pregnant women and women who may soon become pregnant not to eat any shark, swordfish, king mackerel or tilefish. (For pregnant women and children, a safe intake of other fish is about 12 ounces per week, the FDA says.)
Until scientists sort out these issues, here's what experts recommend to help boost omega-3 fatty acids.
Limit processed foods. They are often rich sources of soybean oil and therefore filled with omega-6 fatty acids, which compete against omega-3s for entry into key cells in the heart and brain. By flooding your diet with omega-6s, you make it more difficult for your body and brain to get enough omega-3s, experts say.
Use olive oil. While it's not a huge source of omega-3 fatty acids, substituting it for other oils that are loaded with omega-6s -- safflower, soybean, corn -- can help tip the balance back in favor of omega-3s, says Joseph Hibbeln, chief of the outpatient clinic at the Laboratory of Membrane Biochemistry and Biophysics at the National Institute of Alcohol Abuse and Alcoholism (NIAAA).
Eat varied types of omega-3 foods. Every food group contains them, though not in such high doses as fish. Among the standouts: wild rice, kidney beans, melon, spinach, cauliflower, broccoli, Boston lettuce, gouda and parmesan cheese, cherries, grape leaves and mungo beans. Of course, all of these foods have just a fraction of the omega-3s found in fish and fish oils. Many contain only short-chain omega-3s, which are inefficiently converted by the body to the long-chain omega-3s found in seafood.
To find out how your diet stacks up in terms of omega-3s, you can download a free computer program, Keep It Managed (KIM), at efaeducation.nih.gov/sig/kim.html. Developed by retired NIAAA biochemist William Lands, it uses the U.S. Department of Agriculture's nutrient database of more than 8,000 foods tocalculates the amount of short- and long-chain omega-3 and omega 6 fatty acids in thousands of foods. While it's easy to download, be forewarned: This program provides more information than many people may want to know. Plus, there's a learning curve for new users. But once mastered, the program is easy and fast to use.
Add some flaxseed. And some canola oil, too. Both are good plant sources of omega-3 fatty acids. A tablespoon of flaxseed has four times more omega-3s than omega-6 fatty acids, though you'll need to grind it to get its full benefits. Canola oil has twice the amount of omega-6s as omega-3s: That's a far better ratio than corn, safflower and even olive oil. (Avocados and nuts are also often touted as good sources of omega-3s, but avocados have about 16 times more omega-6s than omega-3s. Nuts provide omega-3 fatty acids, but also a lot of omega-6s.)
Check the oil in canned goods. Many types of tuna and other canned fish come packed in soybean oil, which -- you guessed it -- swamps the omega-3s. Experts say better choices are fish packed in olive or canola oil or in water.
Consider fish oil supplements. If you're not going to follow the American Heart Association's recommendation to eat two servings of fish a week, dietary supplements are another option. Recent testing of 20 fish oil supplements by ConsumerLab.com, based in White Plains, N.Y., found that the products contained no detectable amounts of mercury. By comparison, the testing firm said, fish contains 10 to 1,000 parts per billion of mercury. ConsumerLab did not test these supplements for PCBs. Even so, six of the 20 supplements failed to pass the company's review because they contained less omega-3s than listed on the label -- another reason to consider eating fish and other sources of omega-3s instead of popping pills.