Study Finds Oily Fish Consumption Can Prevent Cardiovascular Disease

Hamilton - Researchers from McMaster University have found in a new study that eating oily fish regularly can help prevent cardiovascular disease (CVD) in high-risk individuals, such as those who already have heart disease or stroke.

In an analysis of several large studies involving participants from more than 60 countries, the researchers found that the critical ingredient is omega-3 fatty acids, which was associated with a lower risk of major CVD events such as heart attacks and strokes by about a sixth in high-risk people who ate two servings of fish rich in omega-3 each week.

No benefit was observed with consumption of fish in those without heart disease or stroke. Further, oily fish but not other types of fish were associated with greater benefits.

The study was published in JAMA Internal Medicine on March 8.

Fish is a major source of the long-chain Omega 3 fatty acids docosahexaenoic acid and eicosapentaenoic acid, which have been suggested to have beneficial effects on cardiovascular health. In interventional studies, fish and Omega-3 consumption have been shown to improve some cardiovascular risk markers, including triglycerides and blood pressure, especially in people with triglycerides of 500 mg/dL or greater (to convert to millimoles per liter, multiply by 0.0113).

"There is a significant protective benefit of fish consumption in people with cardiovascular disease," said lead co-author Andrew Mente, associate professor of research methods, evidence, and impact at McMaster and a principal investigator at the Population Health Research Institute.

"This study has important implications for guidelines on fish intake globally. It indicates that increasing fish consumption and particularly oily fish in vascular patients may produce a modest cardiovascular benefit."

Mente said people at low risk for cardiovascular disease can still enjoy modest protection from CVD by eating fish rich in omega-3, but the health benefits were less pronounced than those high-risk individuals.

The findings were based on data from nearly 192,000 people in four studies, including about 52,000 with CVD, and is the only study conducted on all five continents. Previous studies focused mainly on North America, Europe, China, and Japan, with little information from other regions.

"This is by far the most diverse study of fish intake and health outcomes in the world and the only one with sufficient numbers with representation from high, middle, and low-income countries from all inhabited continents of the world," said study co-lead Dr. Salim Yusuf, professor of medicine at the Michael G. DeGroote School of Medicine and executive director of the PHRI.

This analysis is based on data from several studies conducted by the PHRI over the last 25 years. These studies were funded by the Canadian Institutes for Health Research, several different pharmaceutical companies, charities, the Population Health Research Institute, and the Hamilton Health Sciences Research Institute.

For further reference, log on to: JAMA Internal Medicine