Embrace omega-3 fats — your heart will love you

Forget net carbs and "superfoods." Scan supermarket shelves these days and the marketing phrase screaming loudest is "High in omega-3s!"

Foods naturally rich in omega-3 fatty acids, such as oily fish and avocados, tout themselves as the key to healthy hearts, brilliant brains and eagle eyes. Processed foods, pills and potions fortified with the fats make similar boasts. One supplement says drinking a tablespoon of straight oil each day is "vital for optimal health."

Is this fish oil or snake oil? How can something called a "fatty acid" really be healthy? Does packaged bread back up the claim that it "helps support heart, brain and eye health"? And is that nine-grain slice as good, omega-wise, as 5 ounces of fresh salmon? Or a capsule of fish oil? Or those "omega eggs" that cost an extra dollar per dozen?

Let's cut through the thicket of omega-3 claims to sort out the hype from the helpful.

Omega-3 oils are healthier members of the fat family present in a few foods, including salmon and other oily fish, flax seed, avocados and walnuts. There are three main omega-3s: DHA and EPA (found in cold-water fish, which are fattier than fish from warmer waters) and plant-derived alpha-linoleic acid, or ALA.

"All fats affect the way the liver functions," said Dr. Maureen Mays, director of preventive cardiology at Oregon Health & Science University.

It's what that big fat-processing organ does with different fats that makes some helpful and some harmful. Solid saturated and trans-fats, such as lard and stick margarine, increase bad cholesterol levels, which can lead to heart disease. Unsaturated fats such as olive and safflower oils raise good cholesterol levels and may limit bad cholesterol, Mays said.

Why it's so helpful

Omega-3 is a special, "essential" unsaturated fat — one our bodies can't make but need to run well. Omega-3 fats help build the membranes that surround cells in the body and help make hormones that affect blood clotting and inflammation, according to Harvard University doctors. The fats play some special roles in babies, lining cells in the developing brain and eyes — which is why they're in breast milk and being added to some formulas.

Studies show the fish oils are especially good for the heart, helping prevent deadly rhythm problems and, in high doses, lowering triglycerides — fats circulating in the blood. Concentrated fish oil is even sold as a prescription drug, Lovaza.

"You can take tons and tons and tons of olive oil, and it won't drop your triglycerides," said Mays, who is a board-certified lipidologist, or fats expert. "The omega fats really have a medicinal property that's unique."

Fish fats first intrigued scientists in the 1960s, when they noted surprisingly little heart disease among Eskimos eating "a lot of whale and seal blubber," said Dr. Glenn Gerhard, a Kaiser Permanente Center for Health Research expert on fats.

Research pointed to omega-3s as the heart-helpers. More recent studies suggest the oils may also fight inflammation, rein in blood pressure, limit artery-hardening plaque and cut heart-attack survivors' risk of sudden death.

"I have a patient with Crohn's disease, which is an autoimmune colon disease, and she swears fish oil helps," Gerhard said.

Other benefits

Some scientists think fish oil could also affect depression, dementia, attention deficit disorder, ulcerative colitis, rheumatoid arthritis, allergies, psoriasis and even some cancers, said Dr. Miles Hassell, medical director of Providence Integrative Medicine Program. But those ideas don't have the strong scientific support of omega-3's impact on heart health.

Still, fish oils are fairly low in cost and nontoxic, Hassell said, so they're "an easy thing to add to existing treatment for a defined period ... to see if there is any particular benefit."

The only serious side effect of omega-3 is its ability to thin blood, but there can be other side effects. Mays advised people to talk to their doctor before taking fish-oil pills, especially those who are taking daily aspirin or other blood-thinners.

Pills are just one of a dizzying array of omega-3 sources, along with packaged and natural foods. So which is the best? And how much should you eat?

Fatty fish are generally the best source of omega-3s, experts say, followed by fresh foods including walnuts and ground flax seed.

"I generally like to see people eating avocados, nuts, flax seed [not flax oil] and fish before using supplements," Hassell said, "but we don't have great data that really answers the question." Just how much omega-3 you need to help your heart and health is not known.

Some food packages discuss a "daily allowance" of omega-3s, a slippery claim that manufacturers are allowed to make because the oil is classified as a dietary supplement, which is not regulated by the Food and Drug Administration. Unlike vitamin C or iron, for omega-3s the government has no Recommended Dietary Allowance.

Since few U.S. residents suffer ailments caused by ALA deficiency (most notably a scaly rash), government advisers call the average daily consumption of 1.1 to 1.6 grams of ALA an "adequate intake," noting many people eat less with no problem. There's no parallel level for the omegas found in fish oil (DHA and EPA).

Scientists also can't agree how much omega-3 is ideal, and for whom.

Hassell eats nuts every day, fish several times a week and mixes avocados and ground flax seed into his diet. "I might start taking cod liver oil for both omega-3 fatty acids and vitamin D," he added. For others, Hassell suggests eating 300 to 500 milligrams of omega-3 a day, the amount in an ounce of cooked chinook salmon.

But Mays said the best studies show benefits only from large doses, but again she advises people to check with their doctor before consuming large doses of omega-3.

Mays said that "people who eat a lot of fish tend to do better" for a variety of health reasons.

Best sources

So if you want to add omega-3 to your diet, it's best to do it like the Eskimos: Eat cold-water, fatty fish such as herring, salmon and mackerel (but not king mackerel, which can be high in toxic mercury). Gerhard suggests two 3- to 6-ounce portions of such fish a week.

"If you happen to be someone who likes sardines — there are a few people, not many, not me — they are the most potent source," he said.

Vegetarians or variety-seekers can get ALA from plant foods including avocados, soybeans and pumpkin seeds. A handful of walnut halves or 6 ounces of tofu has a good dose of ALA. Dark, leafy greens also have ALA in smaller amounts.

Flax seed is one of the best ALA sources. Mays advises buying whole seed and grinding it in a coffee mill just before use, since oxygen can spoil the nutrients inside. (Find a dedicated flax grinder, she warns, or your coffee will "taste like grass.")

You can add omega-3 in small doses by cooking with canola or soybean oils, which also have little saturated fat and neutral flavors. "Food wouldn't taste very good if you used fish oil in the pans," Mays said. But heating can harm the omega-3 fats, so you may want to try uncooked oils, such as dressing a salad with walnut oil.

Most important, don't go overboard. Like all fats, omega-3s have 255 calories per ounce of weight. You must balance their health benefits against the excess of calories and fat in the average American diet. Substitute walnuts or fatty fish for less-healthy foods instead of adding them onto a diet that's already ample.

That's especially true with margarines, eggs and other fatty foods now flaunting an omega-3 sheen. "The eggs are a marketing ploy to get people to think, in the back of my mind, 'OK, if I have the omega-3, I don't need to worry about the cholesterol.' Which is totally not true," Gerhard said.

Andy Dworkin is a staff writer for The Oregonian of Portland. He can be contacted at andydworkin@news.oregonian.com.