Heart health is a numbers game. Total cholesterol, LDL cholesterol, blood pressure, triglycerides -- you practically need a personal data assistant to know how worried you should be.
Now some experts want to add yet another number to the mix: the "omega-3 index," a measure of the levels of omega-3 fatty acids in the blood.
Omega-3 fatty acids, naturally found in fish, have a steadying influence on the entire circulatory system. Two of them in particular -- docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) -- have been shown to help control blood pressure, prevent blood clots and encourage healthy heart rhythms.
Unless you're eating salmon with a side of herring for dinner every night, you might wonder if you have enough DHA and EPA in your blood to fully protect your heart.
You could keep wondering, or you could spend $149 for a new at-home blood test.
The Gene Smart Omega 3 Index Heart Health Test, sold online, measures DHA and EPA levels and converts them into an "index" number (specifically, the percentage of fatty acids in red blood cells that are either DHA or EPA.) Users are instructed to collect a drop of blood from a finger after fasting for 10 hours overnight. The blood is then sent to a lab in a provided envelope. Results arrive in about two weeks.
According to the company, an index score of 8% or higher means that a person has enough omega-3s for optimal heart health. A score of 4% or lower is said to be risky. For customers who want to boost their score, the Gene Smart company sells fish oil capsules containing 1.2 grams of DHA and EPA per daily serving. A month's supply costs about $25.
The Gene Smart website ( www.genesmart.com) says that the omega-3 index is a "stronger predictor of heart disease risk than cholesterol." More than 30 years of research have established the protective powers of omega-3s, says Floyd Chilton, the company's chief scientific advisor and a professor of physiology and pharmacology at Wake Forest University in Winston-Salem, N.C. Chilton is also the author of the Gene Smart Diet, a book published earlier this year.
"Given the protective power of omega-3s, everyone should know their levels," Chilton says. Simply eating fish at least two times a week, as recommended by the American Heart Assn., may not be enough, he adds, because people metabolize fatty acids differently thanks to differences in their genes. That's why the company is called Gene Smart. With the guidance of the test, he claims, people can make sure they're getting enough omega-3s to match their genetic needs.
The bottom line
The omega-3 index can certainly give people information about their diets and their hearts, says Dr. Carl J. Lavie, a fellow of the American College of Cardiology and medical director of cardiac rehabilitation and prevention at the Ochsner Heart and Vascular Institute in New Orleans. "I'm a firm believer in omega-3s," he says. "I don't have any problem with anyone who wants to spend $149 to check their levels out. People who have a higher index are likely to be healthier and have more protection."
Still, Lavie and other experts caution that there's far more to heart health than omega-3 levels in the blood. "Omega-3s won't protect people from a heart attack if they smoke and have high LDL cholesterol," he says.
Adds Penny Kris-Etherton, professor of nutrition at Penn State University, "Omegas 3s are a powerful risk factor for heart disease. I think it's definitely helpful to know your levels. But you can't neglect your other risk factors. If you have high cholesterol and high blood pressure, you can't just pop fish oil pills and say, 'I'm protected.' "
Omega-3s seem to be especially helpful for preventing sudden cardiac death, the cause of about half of all heart-related deaths. A study of 278 male doctors, including 94 who had suffered sudden cardiac death even though they didn't have known heart disease, found that low omega-3 blood levels predicted the calamity better than cholesterol. As reported in the New England Journal of Medicine in 2002, the study found that doctors who had the highest levels of omega-3s were about 80% less likely than those with the lowest to suffer sudden cardiac death.
But despite such suggestive evidence, there's still one big piece of the puzzle missing, says Dr. Linda C. Hemphill, a cardiologist at Massachusetts General Hospital in Boston who specializes in blood lipids and cardiovascular risk. No studies have ever proven that people with low omega-3 levels can reduce their risk of heart trouble by taking supplements or eating more fish, she says.
There's also no strong evidence that some people may need more omega-3s than they'd get by sticking to current recommendations, Hemphill says. In addition to the general advice to eat two meals of fish every week, the American Heart Assn. recommends 1 gram of DHA and EPA each day for patients with heart disease and 2 to 4 grams for patients with high triglycerides. "If you follow those guidelines, your omega-3 levels are going to be high," Hemphill says.