Fatty Fish Favors Your Heart

By Paula Rasich Reviewed by Elizabeth Klodas, MD, FACC (CardioSmart) Japanese men who have a high intake of fatty fish — good sources of omega 3 fatty acids — are less likely to develop atherosclerosis than American men whose diets are lacking in these fats, according to a new study.

Japanese men have previously been found to accumulate much less plaque in their arteries when compared to white men living in the United States, despite similar blood cholesterol and blood pressure readings, similar rates of diabetes, and much higher rates of cigarette smoking.

In an effort to explain whether this is due to a genetic advantage or related to other lifestyle factors, an international team of researchers led by Akira Sekikawa, MD, PhD, assistant professor of epidemiology at the University of Pittsburgh, evaluated nearly 900 men between the ages of 40 and 49. One third of the study participants were Japanese, one third were third-generation Japanese Americans, and one third were White Americans.

Researchers measured blood levels of omega-3 fatty acids and performed ultrasound and computed tomography scans to assess plaque buildup on artery walls. The main result of this study was that Japanese men living in Japan had twice the blood levels of omega-3s, compared to Japanese Americans and White Americans, as well as significantly lower levels of plaque buildup. This association remained even after accounting for other cardiovascular risk factors.

“Our study showed for the first time that very high levels of omega-3 fatty acids may have an anti-atherogenic effect,” says Dr. Sekikawa. “And our study clearly demonstrated that the much lower death rate from coronary heart disease in Japan is very unlikely due to genetic factors.” 

On average, Japanese eat fish every day, whereas Americans consume about two servings a week. A comprehensive nutritional study showed that intake of omega-3 fatty acids from fish is 1.3 grams (g) a day for the Japanese and 0.2 g a day for Americans, explains Dr. Sekikawa. 

The omega-3s in fish seem to protect your heart by warding off blot clots and irregular heartbeats. They may also keep blood vessels relaxed and reduce inflammation. Lifetime moderate intake may be the key to reducing heart disease risk.

If you want to make fish a regular part of your diet, consider this: even a small serving can go a long way.  One 3-ounce serving of salmon contains 1.8 g of omega-3s. Other fatty fish high in omega-3 content include sardines, mackerel, rainbow trout, white albacore tuna and bluefish. 

The study is published in the August 5th issue of the Journal of the American College of Cardiology.

Sources:

Sekikawa A. et al.  Marine-Derived n-3 Fatty Acids and Atherosclerosis in Japanese, Japanese Americans and Whites. A Cross Sectional Study.  Journal of the American College of Cardiology, 2008.

Akira Sekikawa, MD, Assistant Professor of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania.