Harvard study finds red meat increases risk of heart disease — fish, nuts and poultry reduce risk

Both the Mediterranean and Asian diet pyramids include only a small area at the top for red meat, which reflects the fact that red meat has never featured prominently in the traditional diets of Asia and the Mediterranean. The main sources of protein in these regions has traditionally come from fish, legumes (beans, peas and lentils), poultry, nuts and shellfish. Red meat was typically reserved for special occasions, or eaten in smaller amounts instead of being the centerpiece of the meal.

A large-scale study just published in Circulation by researchers at Harvard School of Public Health shows just how heart-healthy this pattern of eating can be.

The study analyzed the eating habits of 84,136 women aged 30-55 years with no known cancer, diabetes, stroke, angina or other cardiovascular disease for a period of 26 years. Over that time there were 2,210 documented cases of non-fatal heart attacks and 952 deaths from coronary heart disease.

After adjusting for age, smoking and other factors, researchers found that a high consumption of both processed red meat (such as bacon) and unprocessed red meat (such as steak) was associated with a significantly elevated risk of heart disease. However, it was found that eating more fish, nuts and poultry was associated with a significantly lower risk of heart disease.

The study found that those who had two servings a day of red meat had a 30 percent greater risk of developing heart disease compared to those who had half a serving daily. Researchers also found that those who reported eating one serving of nuts per day were 30 percent less likely to develop heart disease, those who said they ate fish on a daily basis had a 24 percent lower risk, and those who said they ate one serving of poultry per day had a 19 percent lower risk of heart disease.

“Our findings show clearly that source of protein in our diet has an important impact on our health, and we can’t consider red meat, chicken, fish, beans, and nuts to be interchangeable,” said Walter Willett, chair of the Department of Nutrition at Harvard School of Public Health and senior author of the study. “This should not be surprising because when we eat red meat we get a large dose of saturated fat, cholesterol, and a form of iron that can override our control mechanisms. If instead we eat nuts as a protein source, for example, we get unsaturated fats that reduce our blood cholesterol, no cholesterol itself, and lots of fiber, minerals, and vitamins.”