Joanna Cosgrove11.01.08
Omega 3 Testing: Coming to a Doctor Near You?
Knowing one’s omega 3 status could be a more effective predictor of cardiovascular events than a standard cholesterol test.
By
Joanna Cosgrove
Online Editor
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In an August issue of U.S. News & World Report, Bernadine Healy, MD, built a case for increased omega 3 consumption. She explained how omega 3 compounds eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) “become embedded in the membrane of each of the trillions of cells that make up the body, and from that perch influence cell structure and function, including cell-to-cell communication and electrical stability. On demand, they also generate a reservoir of hormone-like molecules to help blood vessels relax, tame inflammation, and reduce blood clotting. All cells feel the pinch of omega 3 deficiencies.”
Moreover, a growing number of studies have confirmed the cardiovascular benefits of omega 3 compounds. “The data for omega 3 fatty acids and the reduction of cardiovascular mortality is extremely robust,” commented Dr. Barry Sears, president, Inflammation Research Foundation. “The GISSI study (more than 11,000 patients) demonstrated that relatively low levels (0.9 grams) of EPA and DHA (but combined with aspirin) resulted in a 20% reduction in mortality compared to the placebo and 45% reduction of sudden death.
“A meta-analysis of all published fish oil and statin studies (accounting for more than 250,000 patients) indicated that fish oil was equal, if not superior, to statins in the reduction of cardiovascular mortality,” he continued. “Finally, the result JELIS study indicated that patients (approximately 18,000) taking statins and 1.8 grams of EPA resulted in 20% fewer cardiovascular events compared to patients taking the statins plus placebo.”
Erminia “Mimi” Guarneri, MD, cardiologist, founder and medical director of the Scripps Center for Integrative Medicine in La Jolla, CA, agrees with Dr. Sears about the important role of omega 3 fatty acids in cardiovascular health, as well as the total body health associated with one’s omega 3 and 6 ratio.
“The research is showing, from the GCP trial and more recently to the JELIS study that there’s a marked decrease in morbidity and mortality in cardiovascular patients that consume omega 3 fatty acids. As a cardiologist I have almost all of my patients on omega 3s for multiple reasons, including anti-arrhythmic and anti-clotting effects, to lower triglycerides, decrease blood sugar,” she said. “We really believe that the omega 3:6 ratio influences inflammation. And we now understand inflammation is the cause for cardiovascular disease, Alzheimer’s disease, memory loss, arthritis—it’s one of the common pathways for disease.”
There are many studies that have looked at different fatty acid ratios, she added. What’s surprising is that they have largely been confined to pregnant women, pediatrics and the depression population—and much less so in the cardiovascular realm. “A very interesting study was done that looked at the phospholipid profile of people from the U.S. (where the cardiovascular risk is 45%) and Europe, compared to Japan (which has much less cardiovascular mortality) and compared it to the Greenland Eskimos, which have the lowest cardiovascular risk at less than 7%,” she explained. “When they looked at the phospholipid contents of the membranes and looked at the omega 3:6 ratios, at the time the study was done, the ratio was 50:1, which is extremely high but a reflection of the American diet at the time. In the Greenland Eskimos, it was 1:1.
“What the cardiovascular research is showing now is that people who have ratios of less than 4:1 decrease their cardiovascular events by about 70%. More research needs to be done so we have a better understanding but the only way to do it is if we measure the levels and understand what we need to do with the inflammation. Quite frankly, we are not up to speed yet. In fact, physicians are just getting up to speed on the fact that omega 3 supplementation is really important.”
Establishing a Test
The reason a test for omega 3 ratios hasn’t yet become as routine as a typical blood serum cholesterol test boils down to the tricky issue of standardization. As Dr. Healy wrote, “not everyone responds the same way to a meal of omega 3s. Genes influence levels of omega 3s in the body, much as they do cholesterol. Some people, such as women of childbearing age, seem to be more effective in generating EPA and DHA from a lesser source, called alpha linolenic acid, found in certain plant oils. And, of course, not every fish meal delivers the same dose of nutrients.”
“Without a reliable, simple measurement of the levels of omega 3 fatty acids in the blood, the optimum amount to give to a person is a guessing game,” concurred Dr. Sears. “There are blood tests available, but they are expensive and not very patient-friendly. My non-profit research foundation is developing a simple finger prick test that can be rapidly analyzed (hence lower cost). Although this test may not be reimbursable at this time, its potential low-cost and ease of use may be ideal for home testing.”
Predicated on data that show the omega 3 content in red blood cells to be a more significant predictor of sudden cardiac death than other traditional biomarkers, including LDL and HDL cholesterol and c-reactive protein, William Harris, PhD, senior scientist and director, Metabolism and Nutrition Research Center, Sanford Research/USD and research professor of medicine, Sanford School of Medicine, University of South Dakota, has also been working to create a standardized omega 3 test since 2002.
“Just like knowing your cholesterol level or blood pressure allows you to take steps to correct abnormal values, knowing your ‘Harris Index for Omega 3s’ (I cannot vouch for the results obtained from other labs) tells you that you need more omega 3 and we can advise you on how much omega 3 you should be eating,” he said. “‘Fixing’ an abnormal HO3I is safe, easy and cheap.”
Dr. Harris asserted that omega 3 compounds are critical for decreasing cardiovascular death. “There is no single dietary component (saturated fat, cholesterol, polyunsaturated fat, salt, fiber, etc) that, if consumed in recommended amounts, would produce the cardiovascular benefits that consuming EPA and DHA in the recommended amounts (500 mg/d in my book for the general population) would produce,” he said. “We have at least three high quality randomized controlled trials in which the only variable was an increase in omega 3 intake to recommended level, and all three trials showed reduced risk for ‘hard’ cardiovascular disease events—heart attacks, strokes, sudden death, and/or hospital admissions for chest pain. The same cannot be said for any other dietary component; none have this level of evidence.”
Dr. Harris expects to have his Harris Index for Omega 3s commercially available by early 2009, with the hope that it will follow the same acceptability trajectory as today’s commonly acceptable cholesterol test, which took between five and eight years before it was routinely administered in doctor’s offices.
Once the Harris Index for Omega 3s is commercially available, Adam Ismail, executive director of GOED (Global Organization for EPA and DHA Omega 3) in Salt Lake City, UT, was confident that not only will patients be able to know their omega 3 number, they’ll also know what to do with it. “Right now doctors primarily recommend fish oil supplements or give their patients a prescription for Lovaza. But that’s all based on the science that it reduces triglycerides and its beneficial role in health, etc.,” he said. “The problem is they just recommend that patients take fish oil and there are definite discrepancies about how much they should take. And when the consumer goes to the shelf to get the product, they don’t know either. Having the Omega 3 Index as an analytical tool for doctors will help monitor patient progress over time, which is something that can’t be done right now.”
Dr. Guarneri said her practice sends its omega 3 blood draws out to the Mayo Clinic because they’re one of the few labs who handle that type of test. “It’s not a standard test as is something like a cholesterol panel, but I believe once we get it standardized and once we get the information easily through insurance companies and so on, it is going to become part of the package,” she said, “especially if more research comes out showing the importance of understanding and manipulating these ratios and having improved health benefits, which we think is the case, based on the data we have right now.”
