Red meat has long been suggested as a contributing factor to a variety of health problems, including Type 2 diabetes and heart disease. But a new analysis from the Harvard School of Public Health indicates that it may be processed meats specifically, rather than red meats per se, that are associated with a higher risk of these conditions.
Using a type of research known as meta-analysis (in which statistics from several studies are combined and examined), researchers looked at 1,218,380 people enrolled in 20 studies that included data about red meat consumption and the incidence of heart disease and diabetes. Unprocessed red meat was defined as any unprocessed meat from beef, lamb, or pork, but not poultry. Processed meat was defined as meat that had been preserved by smoking, curing, salting, or with chemical preservatives. Meats falling into the processed category included bacon, hot dogs, luncheon meats, salami, and sausages.
The data showed that, on average, eating at least one serving a day of processed meat was linked with a 19% greater risk of developing Type 2 diabetes and a 42% greater risk of developing heart disease. The consumption of unprocessed red meats was not associated with the development of these conditions.
Processed meats contain roughly the same amount of saturated fat and cholesterol as unprocessed meats but have four times as much sodium and 50% more nitrate preservatives, on average. In animal experiments, nitrates have been shown to reduce glucose tolerance and promote hardening of arteries, potentially increasing the risk of diabetes and heart disease; a high sodium intake is known to contribute to high blood pressure, which is also a risk factor for heart disease. The researchers suggest that further studies are needed to determine which characteristics of meats are most relevant to health outcomes.
According to lead researcher Renata Micha, RD, PhD, “To lower risk of heart attacks and diabetes, people should consider which types of meats they are eating. Processed meats such as bacon, salami, sausages, hot dogs, and processed deli meats may be the most important to avoid.” In an interview with heartwire, she noted that people “shouldn’t use these findings to eat as much unprocessed red meat as they like,” particularly since both processed and unprocessed meats have been associated with a higher risk of some cancers.
To learn more, read the article “Eating Processed Meats, but Not Unprocessed Red Meats, May Raise Risk of Heart Disease and Diabetes, Study Finds” or see the study’s abstract in Circulation.