Processed Meats May Increase Heart Risk

Daily portions of 1.8oz of processed red meats, such as cold cuts, hot dogs or bacon, may increase the risk of heart disease by 42% and diabetes by 19%, while unprocessed red meats appear to have no negative impact, concludes a study published last week in the American Heart Association journal Circulation.

The study, authored by a group of researchers from Harvard University,  is a meta-analysis grouping the results of 20 studies that covered more than 1.2 million subjects from 10 different countries. While most studies look at red meats as a whole, this one differentiated between processed and unprocessed red meats. Processed red meats were defined as beef, lamp or pork preserved by smoking, curing or salting, or chemical preservatives. 

The team reported that people who ate processed and unprocessed red meats had similar lifestyle factors, and that processed and unprocessed read meats in the US contained similar amounts of saturated fat and cholesterol. The study adjusted for several factors, yet concluded that there was no additional heart or diabetes risk for people who ate only unprocessed red meats, while those who ate processed red meats (1.8oz daily) carried an additional 42% risk of heart disease and 19% risk of diabetes.

"Processed meats contained, on average, four times more sodium and 50 percent more nitrate preservatives," said lead author Micha. It is not clear, however, which factors may be causing the discrepancy measured by the study, or if there is a causal relationship between eating processed meats and heart disease or diabetes. It is possible, for instance, that other aspects of the diet of those who normally eat processed meats could be to blame.

Micha says that having one portion or less a week of processed red meats only increases heart risk by a minor amount. 

In March, another study published by the Journal of Clinical Nutrition, under the supervision of Dr. Ronald M. Krauss, director of atherosclerosis research at the Children’s Hospital Oakland Research Institute, also found no correlation between the risk of heart disease of the amount of ingested saturated fat.

What should you do if you want to keep on eating red meat but are worried about the study results? There is a silver lining in this study, since past studies did not discriminate between processed and unprocessed red meats, and recommended lowering consumption of red meat in general. You might want to simply decrease the percentage of deli meats, ham, bacon, sausage, and hot dogs in the red meat you eat today.

Want to read more about it? Try Reuters, the BBC,  the Wall Street Journal, Food Product Design, Time, Boston.com, NPR, HealthZone, Medical News Today,  and Scientific American.

The study in Circulation