Meat debate reignited: Study links red meat to mortality and CVD

04 Feb 2020 --- Eating two servings of red meat, processed meat or poultry – but not fish – per week is linked to a 3 to 7 percent higher risk of cardiovascular disease (CVD) and a 3 percent higher risk of all causes of death. This is according to a new US study, which contradicts the findings of previous research investigating the same association, spurring an academic discussion on the health impact of red meat. The study authors affirm their conclusions may have critical public health implications.

“It’s a small difference, but it’s worth trying to reduce red meat and processed meat like pepperoni, bologna and deli meats. Red meat consumption also is consistently linked to other health problems, such as cancer,” says senior study author Dr. Norrina Allen, Associate Professor of Preventive Medicine at Northwestern University Feinberg School of Medicine. As many people consume these food types on a daily or weekly basis, these numbers might still be preventable, given that dietary behaviors are modifiable. 

The new findings come hot on the heels of a controversial meta-analysis that recommended people not reduce the amount of red meat and processed meat they eat. “Everyone interpreted that it was alright to eat red meat, but I don’t think that is what science supports,” Dr. Allen says.

Regular consumption of red and processed meats is linked to CVD and death, the study finds.Of the nearly 30,000 US study participants with an average age of 54 years pooled from six prospective cohort studies, the new study revealed a 4 percent higher risk of CVD for people who ate two servings per week of poultry. Throughout the 19 years of follow-up research, there were 6,963 incident CVD events and 8,875 all-cause deaths.

The study identifies its limitations as participants’ dietary intake and dietary behaviors having changed over time. In addition, cooking methods were not considered.

The study’s present evidence is insufficient to make a clear recommendation about poultry intake, the researchers maintain. Moreover, the relationship may be related to the method of cooking the chicken and consuming its skin rather than the chicken meat itself. Still, fried chicken is not recommended.

The researchers did not establish an association between eating fish and CVD or mortality. “It is interesting that there was no beneficial association for fish intake, but that might be – as the authors explain – since they could not distinguish between different types of fish preparation. In general, a beneficial effect could have been expected,” says Professor Gunter Kuhnle, Professor of Nutrition and Food Science, University of Reading, UK, who was not involved in the study.

Different perspectives yield different results
A different perspective may be the reason between the conflicting results of the latest study and the previous one. While the earlier study focused on individual decision making, the newer study took a public health approach.

“The [previous] study’s authors took the line that the risk differences were small and that many individuals who eat meat would consider that such small differences in disease risk are unimportant when looked at beside the enjoyment they get from what they eat or the awkwardness of changing eating habits,” says Professor Kevin McConway, Emeritus Professor of Applied Statistics, The Open University, UK, who was not involved in either study. 

Plant-based meat options are facing intense scrutiny amid surging sales.“The researchers on the new study are taking a public health perspective. They note that people can choose to eat less meat, and if they do so and the relationship between meat eating and disease risk is indeed causal, then fewer people would have heart attacks and strokes. Therefore, on average, people would live a bit longer,” he continues.

Personalized eating patterns may play a key role as well, with the effects of red meat intake varying from person to person. Because people who eat different amounts of the meat also differ in many other ways, these other differences may be what really cause the differences in the risks of CVD and of deaths that are earlier than would otherwise have occurred.

In terms of absolute risk, the increase in absolute risk is so small that it is unlikely to be relevant for the individual, says Professor Kuhnle. “There is no need to stop eating meat.”

On a population level, however, the statistics gain more importance, he continues. “With about one million people being diagnosed with heart disease every year, even a small reduction in absolute risk can have a considerable effect and reduce the number of people suffering.”

What should we eat instead?
The study found a positive association between poultry intake and CVD, but the evidence so far isn’t sufficient to make a clear recommendation about poultry intake, says lead study author Dr. Victor Zhong, Assistant Professor of Nutritional Sciences at Cornell. 

“Fish, seafood and plant-based sources of protein such as nuts and legumes, including beans and peas, are excellent alternatives to meat and are under-consumed in the US,” adds study co-author Dr. Linda Van Horn, Professor of Preventive Medicine at Feinberg.

The plant-based diet is enjoying sustained popularity in the mainstream, with Innova Market Insights reporting that as many as 10 percent of US consumers claim they always buy meat alternatives. A further 36 percent claim to do so often or sometimes. 

As people around the world turn away from animal-derived foods, the market for meat analogs that look, feel and taste like meat continues to boom. However, many argue that numerous plant-based meat alternatives are more processed and contain more salt than traditional meat. The recent study authors warrant further investigations to continue the discussion.

Edited by Anni Schleicher