The study – published in JAMA’s Archives of Internal Medicine – report that intake of red meat is associated with increases in all-cause mortality, and specifically increases the risk of death from cardiovascular disease and cancers. The authors add that substituting other sources of protein such as fish, nuts, and poultry for red meat was found to lower the risks.
"We found that a higher intake of red meat was associated with a significantly elevated risk of total, CVD and cancer mortality, and this association was observed for unprocessed and processed red meat, with a relatively greater risk for processed red meat," wrote the authors, led by An Pan of the Harvard School of Public Health, USA.
"We estimated that 9.3 percent in men and 7.6 percent in women of total deaths during follow-up could be prevented if all the participants consumed fewer than 0.5 servings per day of total red meat in these cohorts," they commented.
"Our study adds more evidence to the health risks of eating high amounts of red meat, which has been associated with type 2 diabetes, coronary heart disease, stroke, and certain cancers in other studies," Pan added.
Pan and her colleagues analysed data from two prospective cohort studies, containing data from 37,698 men and 83,644 women. All participants were free of cardiovascular disease (CVD) and cancer at baseline. Diets were assessed through questionnaires every four years, said the authors.
A combined 23,926 deaths were documented in the two studies – of which 5,910 were from CVD and 9,464 from cancer, said the authors.
Regular consumption of red meat, particularly processed red meat, was found to be associated with increased mortality risk: one daily serving of unprocessed red meat was associated with a 13% increased risk of mortality, whilst one daily serving of processed red meat was associated with a 20% increased risk.
When looking at specific causes of death, the authors said the corresponding risks were 18% (unprocessed) and 21% (processed) for cardiovascular mortality, and 10% and 16% for death from cancer.
Pan and her colleagues said the analyses took into account chronic disease risk factors such as age, body mass index, physical activity, family history of heart disease, or major cancers.
Red meat risk
The research team noted that red meat, especially processed meat, contains ingredients that have been linked to increased risk of chronic diseases, including cardiovascular disease and cancer. These ingredients include heme iron, saturated fat, sodium, nitrites, and certain carcinogens that are formed during cooking.
They explained that replacing one serving of red meat with one serving of a ‘healthy’ protein source was found to be associated with a lower mortality risk: 7% for fish, 14% for poultry, 19% for nuts, 10% for legumes, 10% for low-fat dairy products, and 14% for whole grains.
Professor Frank Hu of Harvard School of Public Health – and senior author of the paper – commented that the findings provide “clear evidence that regular consumption of red meat, especially processed meat, contributes substantially to premature death."
"On the other hand, choosing more healthful sources of protein in place of red meat can confer significant health benefits by reducing chronic disease morbidity and mortality," said Hu.
Source: Archives of Internal Medicine
Published online ahead of print, doi:10.1001/archinternmed.2011.2287
“Red Meat Consumption and Mortality: Results From 2 Prospective Cohort Studies”
Authors: A. Pan, Q. Sun, A.M. Bernstein, M.B. Schulze, J.E. Manson, et al