SAN ANTONIO (AHA) — Older individuals are less likely to die from a heart attack if they eat at least one serving of fatty fish per week, according to a study presented at the American Heart Association's 41st Annual Conference on Cardiovascular Disease Epidemiology and Prevention.

Eating fatty fish at least once per week was associated with a 44 percent lower risk of dying from a heart attack among a group of older adults, average age 72. In contrast, eating fried fish — which is typically lean — was not associated with a lower risk of dying from a heart attack. Examples of fatty fish are tuna, salmon and mackerel; examples of lean fish are cod, catfish and snapper.

"Our findings are consistent with results of prior studies done in predominantly middle-aged adults," says Dariush Mozaffarian, M.D., lead author of the study and fellow in cardiology and health services research at the University of Washington/Seattle Veterans Affairs Medical Center.

Fish is thought to protect against death from heart attack because it contains good fats called omega-3 (or n-3) polyunsaturated fatty acids (PUFAs). "Fatty fish are more abundant in omega-3 fatty acids, while fried fish are typically lean fish without significant omega-3 fatty acids. Because these omega-3 fatty acids may protect against dying from a heart attack, eating fatty fish may be of greater benefit than eating fried fish," says Mozaffarian.

The researchers found that individuals with a higher intake of fatty fish had higher plasma levels of omega-3 PUFAs. There was no correlation between intake of fried fish and plasma levels of omega-3 PUFAs.

Many deaths from heart disease are due to cardiac arrhythmias, or heart rhythm disturbances, and omega-3 fatty acids may reduce the risk of arrhythmias, he says.

"The study suggests that modest consumption of fatty fish at any age may be beneficial," says David S. Siscovick, M.D., professor of medicine and epidemiology, and co-director of the University of Washington Cardiovascular Health Research Unit, and a co-author of the study. "When encouraging people to eat a healthy diet, it may be important to differentiate which types of fish are good sources of omega-3 fatty acids," he says.

Researchers analyzed the relationship between eating fatty fish, eating fried fish and the risk of fatal heart attack and coronary heart disease deaths among nearly 4,000 men and women older than age 65 involved in the National Heart, Lung and Blood Institute’s Cardiovascular Health Study, launched in 1988 to assess the determinants of heart disease and strokes among older adults.

At the beginning of the study, all participants were free of known cardiovascular disease. Mozaffarian and his colleagues used a detailed food questionnaire to assess the participants’ usual diet. Participants were followed for an average of 6.8 years.

The researchers did not determine which specific types of fatty fish were consumed, therefore it is not possible to recommend one type of fatty fish, tuna or salmon, for example, over another.

"The study highlights the benefit of one or two servings per week of fish rich in omega-3-PUFAs, not all fish," says Siscovick.

In October 2000, the American Heart Association issued updated dietary guidelines for healthy adults, which recommend eating at least two servings of fatty fish per week. For more information on the 2000 dietary guidelines visit www.americanheart.org.

Co-authors of the study are Rozenn N. Lemaitre, Ph.D.; Lewis H. Kuller, M.D.; Greg Burke, M.D., Caroline Blaum, M.D., and Russell Tracy, Ph.D.

Copyright 2001 The American Heart Association. All rights reserved.