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No, beef isn't bad for you: Scientists conclude there is no need to eat less red or processed meat


New guidelines certain to be celebrated by enthusiasts of the carnivore diet and denounced by others as nutritional heresy recommend most adults shouldn’t worry about eating less red or processed meat.

The recommendations — which conflict with virtually every other in existence, including the latest iteration of Canada’s food guide — are based on studies involving millions of people. The authors found lowering red or processed meat consumption had little, and often-trivial effects in reducing the absolute risk for cardiovascular disease, stroke, heart attack, cancer, diabetes or death from any cause.

Researchers at Dalhousie and McMaster universities led the panel of international scientists. On the basis of four systematic reviews assessing the risks of red and processed meat, “we suggest that individuals continue their current consumption,” the authors write in the Annals of Internal Medicine.

“We cannot say with any certainty that eating red or processed meat causes cancer, diabetes or heart disease,” said Dr. Bradley Johnston, an associate professor of community health and epidemiology at Dalhousie, and lead author of the recommendations.

“This is not just another study of red and processed meat,” he said in a statement, “but a series of high quality systematic reviews resulting in recommendations we think are far more transparent, robust and reliable.”

What’s more, a fifth review found that most omnivores are highly attached to their meat, men especially so.

The researchers didn’t consider animal welfare or environmental concerns, including meat-eating’s possible contribution to global warming. However, people who choose not to eat meat (vegetarians) report health as one of the main reasons for avoiding it, Johnston said. “However, any health benefits from staying away from meat are uncertain, and, if they exist at all, are very small.”

For years, health groups have been beating the drums that red and processed meat increase the risk of a premature death, Dr. Aaron Carroll, author of The Bad Food Bible, wrote in an accompanying editorial . In 2015, an august panel of experts, the World Health Organization’s International Agency for Research on Cancer, declared bacon, sausages, biltong, beef jerky and other salted, cured, smoked or similarly prepared meats carcinogenic, and red meat “probably” carcinogenic, too. Canada’s new food guide recommends Canadians choose proteins that come from plants, and not animals, more often. American dietary guidelines recommend limiting red meat to approximately one weekly serving.

“We have saturated the market with warnings about the dangers of red meat,” Carroll, of the Indiana University School of Medicine, writes with co-author Tiffany Doherty. “It would be hard to find someone who doesn’t ‘know’ that experts think we should all eat less.

However, “Continuing to broadcast that fact, with more and more shaky studies touting potential small relative risks, is not changing anyone’s mind.”

The new recommendations, however, are already getting pushback. The authors readily admit that their recommendations come with a “low certainty of evidence,” noted Dr. Joe Schwarcz, of McGill University, “because the studies themselves have low certainty of evidence.”

Nutritional studies are mostly observational, meaning they can’t prove cause-and-effect. They rely on people to accurately report what they have eaten, and researchers follow participants over time and observe what happens. “People tend to claim that they eat more of what they think they should have eaten instead of what they ate,” said Schwarcz, director of McGill’s Office for Science in Society.

And, in the case of meat, the environmental impact can’t be ignored. “While eating less meat may not have a great benefit for the consumer,” Schwarcz said, “it can have a significant impact on the environment. And it certainly has an effect on the animal that is not consumed.”

Still, the recommendations, appearing in a reputable journal, will have some heft. Current estimates are that adults in North America and Europe consume red and processed meat about three to four times per week, on average.

For the majority of people, but not everyone, continuing their red and processed meat consumption is probably the right approach

The Dalhousie and McMaster researchers, together with researchers from Poland and Spain, performed five systematic reviews.

One included more than 100 studies involving more than six million people. The analysis found that differences in red and processed meat consumption resulted in only small differences in the risk of dying from cardiovascular disease, stroke, heart attack or type 2 diabetes. In another meta-analysis — a study of studies — looking specifically at the risk of developing or dying from prostate, esophageal, colorectal, breast or other cancers, again they found any link with meat was small.

People who ate three fewer servings of red or processed meat per week did seem to slightly reduce their risk of heart disease, cancer and diabetes, but again the association seemed shaky.

For example, with cancer, “we see risk reductions of anywhere from one to 13 cases per 1,000 people followed over a lifetime,” Johnston said in an interview. “So, that’s 0.1 per cent to 1.3 per cent. That’s our best estimate.”

The numbers were similar for heart disease and diabetes — anywhere from one to 20 fewer cases per 1,000 people followed.

“Our approach has been there is a possible reduction, that’s true. But what’s also true is that we’re uncertain whether we can make a causal inference,” Johnston said.

“And if that’s the case people should know what their possible risk reduction is, if it exists at all, and be informed of that so they can make their own decisions.”

A separate analysis of people’s values and preferences towards meat found that, for those who eat meat, they generally like the taste of it, and are unlikely to stop.

Overall, the 14-member panel concluded that, for most people, “the desirable effects (a potential lowered risk for cancer and cardiometabolic outcomes) associated with reducing red meat consumption probably do not outweigh the undesirable effects (impact on quality of life, burden of modifying cultural and personal meal preparation and eating habits).”

“We don’t feel the evidence is strong enough to tell people, as a whole, to reduce their consumption,” Johnston said. “For the majority of people, but not everyone, continuing their red and processed meat consumption is probably the right approach,” he said. (People with health concerns, or who eat high amounts of meat, might need to reduce their intake and should speak with their healthcare provider, he said.)

While “excellent scientists,” Dr. David Jenkins disagreed with the panel’s conclusions. “They should not be making recommendations on this highly connected and sensitive issue, namely, meat consumption, linked as it is to GHGE (greenhouse gas emissions), climate change, our whole attitude to other life forms — in short, connected to existential issues for life on this planet,” said Jenkins, a University of Toronto nutrition scientist and staff physician at St. Michael’s Hospital.

A pattern of low meat intake was slightly protective for cardiovascular disease, cancer and diabetes. While the quality of evidence was low, “if the risk is significant, statistically, then I’m not interested. I don’t want it,” Jenkins said.

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