Fish Oil Won't Save Diabetics' Hearts, Research Suggests

MONDAY June 11, 2012 -- People with type 2 diabetes who take omega-3 fatty acid supplements are neither helping nor harming their heart, a new study finds.

Omega-3 fatty acids -- the type found in fish oil -- are hugely popular because research has linked them to a reduction in heart attacks, strokes and other cardiovascular problems. However, this study found no such benefits among people with type 2 diabetes, the researchers say.

"Previous studies had suggested that fish-oil supplements may have a modest benefit in these outcomes -- we did not find that at all," said researcher Dr. Hertzel Gerstein, a professor of medicine at McMaster University in Hamilton, Ontario, Canada.

Perhaps diabetics react differently to these supplements, or their risk of cardiovascular disease is so severe that a higher dose of the supplement would be needed to see an effect, Gerstein said.

"If you want to prevent cardiovascular disease, heart attacks and strokes, going out and buying omega-3 fatty acids is not going to do it," he said.

Type 2 diabetes, a condition linked to being overweight and marked by excess blood sugar, can lead to serious health problems, including heart disease and stroke, if it's uncontrolled.

The report was published June 11 online in the New England Journal of Medicine to coincide with the planned presentation of the study findings at a meeting of the American Diabetes Association in Philadelphia.

For the study, more than 12,500 people with type 2 diabetes or prediabetes and at high risk of cardiovascular events were randomly assigned to take a daily, 1-gram omega-3 fatty acid supplement or an inactive placebo. Over roughly six years, the researchers looked for deaths from cardiovascular causes.

The investigators found that taking an omega-3 fatty acid supplement had no effect on deaths from heart attack, stroke, other cardiovascular causes or any other cause.

The supplement did lower the levels of triglycerides, which may be an indicator of cardiovascular disease risk. But omega-3 fatty acid supplements had no effect on other lipids, such as "good" HDL cholesterol and "bad" LDL cholesterol, the researchers noted.

Dr. Joel Zonszein, professor of clinical medicine at Albert Einstein College of Medicine and director of the Clinical Diabetes Center at Montefiore Medical Center in New York City, said few studies have shown convincingly that treating high triglycerides or low HDL cholesterol improves cardiovascular outcomes.

"These lipoproteins, while good markers, do not appear to benefit when treated, particularly when compared with statins," he said.

"Treating LDL cholesterol, especially in patients with type 2 diabetes, is critical, and statins are best," Zonszein said.

Another expert, Dr. Spyros Mezitis, an endocrinologist at Lenox Hill Hospital in New York City, said patients ask about whether or not they should take omega-3 supplements to lower cholesterol.

"We tell them that statins are drugs that are proven to lower the bad cholesterol and are associated with a reduction in cardiovascular risks," he said.

There are patients who take fish oil on their own, Mezitis said. "We tell these patients they can continue taking fish oil, but it doesn't take the place of a statin," he said.

The study was funded by drug maker Sanofi.

More information

For more information on diabetes, visit the American Diabetes Association.

Posted: June 2012


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