BOSTON – A study published June 12 in The BMJ found an association between an increase in red meat intake and a heightened risk of death.
The study, which involved gathering data from more than 80,000 people in two other studies, showed increasing red meat intake by 3.5 servings a week or more over an eight-year period was associated with a 10 percent higher risk of death in the next eight years. The association was 13 percent for processed red meat like bacon, hot dogs, sausages and salami and 9 percent for unprocessed red meat. The associations largely were consistent across different age groups, levels of physical activity, dietary quality, smoking and alcohol consumption habits.
Reducing red meat intake while eating more whole grains, vegetables or other protein foods such as poultry without skin, eggs and fish was associated with a lower risk of death. An example was one serving of fish per day replacing one serving of red meat, which was linked to a 17 percent lower risk of death in the subsequent eight years.
The North American Meat Institute (NAMI) responded with a statement: “Health outcomes are far more complicated than matching a single type of food to causes of death. The latest study out of Harvard is another attempt by researchers there to take self-reported data based on food consumption questionnaires filled out by study participants every four years and try to draw broad conclusions. Many experts have criticized this approach to nutrition science for its vague and often confusing conclusions. It is akin to relying on consumers’ personal characterization of their driving habits as a teenager in determining their likelihood of having an accident that kills them in the future. It has a high likelihood of giving erroneous results.
“Much like other studies of this nature, these results are very weak, showing weak associations and results are impossible to disentangle other lifestyle and dietary habits from meat and processed meat consumption based on observational data that is not meant to prove causality. Rather than focusing on the headlines in a press release, media and consumers should look to the total body of evidence on meat consumption, which is clear that meat is a nutritious part of a healthy balanced diet. Federal nutrition data shows that the protein group is the only food group consumed at proper levels and that Americans, on average, consume the recommended amount of meat. For overall health what the total evidence has shown, and what common sense suggests, is that a balanced diet and a healthy body weight are the keys to good health.”
The study in The BMJ may be found here. It involved researchers from the Harvard T. Chan School of Public Health in Boston; Harvard Medical School in Boston; Ohio Univ. in Athens, Ohio; Fudan Univ. in Shanghai; Huazhong Univ. of Science and Technology in Wuhan, China; and Universidad Autonoma de Madrid in Madrid.
Data in the study were taken from 53,553 US registered female nurses from the Nurses’ Health Study and 27,916 US male health professionals from the Health Professionals Follow-up Study. All participants were free of cardiovascular disease and cancer at baseline. Participants completed a food frequency questionnaire every four years. Researchers examined the link between changes in red meat consumption over an eight-year period with mortality during the next eight years. They looked at data as far back as 1986 with the follow-up ending in 2010. A total of 14,019 deaths occurred.
The study, being an observational one, could not establish cause, but the researchers gave several possible reasons for the link between red meat consumption and risk of death. Saturated fat, cholesterol and heme iron in red meat could accelerate atherosclerotic processes and affect the incidences and prognosis of hypertension, hypercholesterolemia, endothelial dysfunction, insulin resistance and type 2 diabetes. The sodium level in processed red meat is a risk factor for hypertension and vascular stiffness, which might increase mortality caused by stroke, myocardial infarction, arterial stiffening, heart failure and renal insufficiency.