Study linking red meat to high mortality under fire

The American Meat Institute (AMI) said the study’s main flaw was the fact that it relied on self-reporting to survey participants’ diets, but that the method of collecting data was also “highly inaccurate”​. According to AMI, the researchers inserted estimated data when actual survey measurement was missing, and stopped updating the dietary information as soon as participants reported a diagnosis.

“Too often, epidemiological findings are reported as ‘case closed’ findings, as if a researcher has discovered the definitive cause of a disease or illness. But epidemiological studies look at a multitude of diet and lifestyle factors in specific volunteer human populations and use sophisticated statistical methods to try and tease out relationships or associations between these factors and certain forms of disease. This method of comparing relationships has many limitations, which are widely recognised by researchers in this field. More often than not, epidemiological studies, over time, provide more contradictions than conclusions,”​ said Betsy Booren, AMI foundation director of scientific affairs.

The organisation compared the method used to assess people’s dietary habits to “relying on consumers’ personal characterisation of their driving habits in prior years in determining their likelihood of having an accident that kills them in the future”​, adding that the results were likely to be erroneous.

“Red and processed meat continues to be a healthy part of a balanced diet and  nutrition decisions should be based on the total body of evidence, not on single studies that include weak and inconsistent evidence and stand in contrast to other research and to the Dietary Guidelines for Americans, 2010.​

“All of these studies struggle to disentangle other lifestyle and dietary habits from meat and processed meat and admit they cannot do it well enough to use their conclusions to accurately recommend people change their dietary habits. 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,”​ added Booren.

"Red meat contributes to premature death", study claims​

The study, by Harvard School of Public Health (HSPH) researchers, followed 37,698 men for up to 22 years and 83,644 women for up to 28 years, who were free of cardiovascular disease (CVD) and cancer at baseline. Questionnaires were sent to participants to assess dietary changes every four years.

A combined 23,926 deaths were recorded, including 5,910 from CVD and 9,464 from cancer. The authors concluded that regular consumption of red meat, particularly processed red meat, was associated with increased mortality risk, but noted that “men and women with higher intake of red meat were less likely to be physically active and were more likely to be current smokers, to drink alcohol, and to have a higher body mass index”.​

One daily serving of unprocessed red meat was associated with a 13% increased risk of mortality (18% for CVD and 10% for cancer), and one daily serving of processed red meat was associated with a 20% increased risk (21% for CVD and 16% for cancer).

Replacing one serving of red meat with other protein sources, such as fish, poultry or nuts, was associated with a lower mortality risk.

“This study provides 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,”​ concluded Frank Hu, professor of nutrition and epidemiology at HSPH and one of the authors of the ‘Red Meat Consumption and Mortality’ study.