You've no doubt heard advice to eat a couple of servings of fish each week to get omega-3 fatty acids and their important health benefits. Don't like fish? Supplements, some coated to prevent an aftertaste, are easy to find. And many food manufacturers are fortifying products from milk to cereal with omega-3s. But why do these fatty acids matter? How much do you need? And what's the best source?
The buzz over fish oil
Omega-3s are most famous for heart health benefits, but they're also linked with relieving depression, attention deficit disorder, arthritis pain, asthma and Crohn's disease. They may also reduce the risk of certain cancers, Alzheimer's disease and sight-robbing macular degeneration, to name just a few.
The key is the oil's ability to reduce inflammation, especially in the joints, blood vessels and brain. Research continues, but experts say there's enough evidence to recommend that most of us increase our daily intake.
DHA, EPA, ALA, oh my
Ever looked at a fish oil supplement label and felt like you were drowning in alphabet soup? Here's a quick primer:
Omega-3s are made up of a number of different fatty acids. The most well-known are abbreviated as DHA, EPA and ALA. Scientists think we need all three of them to get the full benefits, but DHA and EPA have been the most rigorously studied. They are usually found together in oily fish that live in cold water.
ALA comes from plants. The body has to convert it into DHA and EPA to be beneficial, but only about 5 to 15 percent of ALA makes the conversion.
"We know EPA and DHA benefit the heart,'' said Jose Barboza, a pharmacist and assistant professor at the University of South Florida College of Pharmacy. "But the research on ALA isn't as good. That's not to say ALA isn't important. Much more study is needed."
How much is needed?
There are no federal guidelines, but the American Heart Association and the Institute of Medicine recommend 1.1 grams (1,100 milligrams) for women and 1.6 grams (1,600 milligrams) for men of combined DHA and EPA daily.
Food for thought
Wild salmon may be the best fish source of omega-3s, with a 3-ounce serving containing 1,000 to 1,500 milligrams of DHA and EPA combined. Other good sources include farm-raised salmon (though chemical toxins may be a concern), tuna, trout and sardines. Some fish may contain high levels of mercury, so pregnant women, nursing mothers and young children may be cautioned to avoid it.
Walnuts are an excellent source of ALA — a 1-ounce serving has 2.5 grams. Flaxseed oil is another good source and can be used in cooking or blended into smoothies.
What about flaxseeds, which are increasingly turning up in food products that claim to be good for you?
"If it's whole flaxseeds, say in a protein bar or cereal, they are of no benefit, because our bodies can't break down that seed. To get the omega-3 benefit, it must be ground," said Tampa General Hospital registered dietitian Carol Quartana.
You'll also find ALAs in certain leafy greens and legumes, including soy (see details, right).
Quartana points out that many fortified and plant-based foods contain just one of the three omegas, and you need all three to get the full benefit. So read the fine print.
Tally it up
Don't go overboard if calories matter to you. Oils, healthy or not, deliver 120 calories per tablespoon. An ounce of walnuts has 190 calories. So watch those portions.
Likewise, some manufacturers command a price premium for fortified foods that aren't always worth it in terms of fatty acid value. Omega-3-fortified eggs have only 115 milligrams of DHA, EPA and ALA combined. A regular large egg has about 49 milligrams, and generally is far cheaper — sometimes a couple of dollars per dozen.
"You would have to eat more than a dozen (fortified) eggs to get the recommended daily dose of omega-3s,'' said registered dietitian Marisa Moore, a spokeswoman for the American Dietetic Association. "It's not worth the extra calories or price. I tell patients to go with a more efficient source to get more bang for your buck."
And that's almost always going to be fish or fish oil supplements.
Omegas in a pill
Fish oil supplements are a good alternative if you can't get enough omega-3s in your diet, but stay within recommended limits. Taking too much can increase the risk of bleeding, especially if you also take blood thinners like Coumadin, warfarin and Plavix.
Dietary supplements are not regulated by the federal government, so look for known brands that are verified by independent labs such as USP (United States Pharmacopeial Convention) for purity, potency and quality.
Algae and krill oil supplements are an increasingly popular source of omega-3s for vegetarians. But research is lacking on their protective powers.
"We just don't have the data on it,'' Barboza said. "If you can't get omega-3s from fish, algae or krill oil may be better than nothing, but we're still finding out about it."
Irene Maher can be reached at firstname.lastname@example.org.