Eating scallops that are broiled or baked, but not fried, may reduce risk of atrial fibrillation, the most common type of heart arrhythmia, especially in the elderly, according to a Harvard study published in the July 2004 issue of Circulation.
In the 12-year study of 4,815 people 65 years of age or older, eating canned tuna or other broiled or baked fish 1 to 4 times a week correlated with increased blood levels of omega-3 fatty acids and a 28% lower risk of atrial fibrillation. Eating broiled or baked fish 5 times a week lowered risk even more—a drop in atrial fibrillation risk of 31%. Eating fried fish, however, provided no similar protection. Not only is fried fish typically made from lean fish like cod and Pollack that provide fewer omega-3 fatty acids, but in addition, frying results in the production of damaged, free-radical-laden fats in the fish as well as the frying oil.
In further research to determine if the omega-3 fats found in fish oil were responsible for fish's beneficial effects on the heart's electrical circuitry, Dariush Mozaffarian and colleagues from Harvard Medical School analyzed data on fish intake and electrocardiogram results from 5096 adults, aged 65 or older, who were enrolled in the Cardiovascular Health Study from 1989-1990.
Eating tuna or other broiled or baked fish at least once a week was associated with lower heart rate (-3.2 beats/minute) and a 50% lower likelihood of prolonged ventricular repolarisation (the period of time it takes the heart to recharge after it beats, so it can beat again), compared to those consuming fish less than once a month.
Consuming 1 gram/day of omega-3 fatty acids from fish was associated with 2.3 beats/minutes lower heart rate and a 46% lower risk of prolonged ventricular repolarisation. Eating fish at least 5 times per week was associated with an even healthier heart rhythm. However, eating fried fish (typically sold in the U.S. as fish burgers or fish sticks) was not associated with increased blood levels of omega 3 fats or any beneficial electrocardiogram results. In fact, a previous study led by the same researcher (Mozaffarian, Am J Cardiol 2006 Jan) found that while eating baked or broiled fish was linked to a slower but more powerful heart beat and lower blood pressure, eating fried fish was associated with heart muscle motion abnormalities, a reduced ejection fraction, lower cardiac output, and higher blood pressure. Since irregular heart beats are a major precipitating factor in sudden death due to cardiac arrest, promoting a healthy heart rhythm by eating baked or broiled—not fried—fish several times a week makes very good sense. Happily, as our recipes, such as our serving ideas for scallops (immediately below) show, it's a quick, easy and most importantly, delicious prescription.