OVER the past two million years human beings have successfully evolved on a diet which has included regular intakes of red meat.

It’s hard to pinpoint exactly when it changed but at some point in recent decades meat shifted from being an unquestioned part of a healthy diet to one of the chief villains in public and media messaging about unhealthy foods.

However, a scientific study has been published this week which has challenged the methods of research upon which many of the dietary warnings against red meat have been based, and its findings aren’t being well received by public health officials.

The study published in Annals of Internal Medicine on Monday, as summarised by the BBC, said “cutting down on sausages, mince, steak and all other forms of red or processed meat is effectively a waste of time for most people”.

The study’s authors found that most people can continue to eat red and processed meat at the current average intake, typically three or four times a week for adults in North America and Europe.

The study comprised a series of reviews of both randomised controlled trials and observational studies looking at the possible health impact of eating red and processed meat.

The randomised trials which included around 54,000 people found no statistically significant link between eating meat and the risk of heart disease, diabetes, or cancer.

“Our bottom line recommendation … is that for the majority of people, but not everyone, continuing their red and processed meat consumption is the best approach,” Bradley Johnson, an associate professor at Dalhousie University in Canada who was involved the study, told the media.

“Based on the research, we cannot say with any certainty that eating red or processed meat causes cancer, diabetes or heart disease,” he said.

Constantly changing dietary messages are nothing new – remember the ‘butter is good for you, butter is bad you, hang-on – butter is good for you again!’ episode in recent years? (See also this comprehensive post on the health effects of butter from food blogger Gerard Paul’s Many Eats site)

There is nothing new in the science that shows red meat is an important source of nutrition in a healty, balanced diet.

This week’s study has received solid coverage in mainstream media, with a sample of headlines including:

New review gives thumbs up to red meat (The Australian)

Is red meat back on the menu? (BBC News)

Eat Less Red Meat, Scientists Said. Now Some Believe That Was Bad Advice. (The New York Times)

Is eating beef healthy? The new fight raging in nutrition science, explained (Vox)

The BBC reported that statisticians have broadly supported the way the study has been conducted, with one describing it as an “extremely comprehensive piece of work” .

Prof David Spiegelhalter, from the University of Cambridge, said: “This rigorous, even ruthless, review does not find good evidence of important health benefits from reducing meat consumption.

“In fact, it does not find any good evidence at all.”

However, officials from Public Health England told the BBC they have no intention of reviewing their advice on limiting meat intake.

One group of doctors from universities including Harvard, Yale and Stanford, including one of the study authors, requested in a letter to the journal that it “pre-emptively retract publication” of the papers, pending further review, according to the Australian. They said revised guidelines that could lead to increased consumption of red and processed meats would be irresponsible.

A statement scheduled for publication by the Harvard T.H. Chan School of Public Health said, “from a public health point of view, it is irresponsible and unethical to issue dietary guidelines that are tantamount to promoting meat consumption, even if there is still some uncertainty about the strength of the evidence.”

From their reaction it is hard to imagine how humans managed to survive, let alone thrive, over the past two million years given the red meat they consumed along the way.

There is a valid point to be made that moderation in everything is important (even eating too much salad can be bad for you!), and that evolving humans ate less and exercised more than a typical developed-world consumer today – eating meat depended on their ability to hunt it down on foot, as opposed to driving to the nearest supermarket or food outlet or pub.

But the latest experience is another example of how imperfect data can be used to crucify products that don’t align with particular agendas:

The study notes that many contemporary dietary guidelines recommend limiting consumption of unprocessed red meat and processed meat, including the 2015–2020 Dietary Guidelines for Americans, the United Kingdom dietary guidelines and the World Cancer Research Fund/American Institute for Cancer Research. It adds that World Health Organization International Agency for Research on Cancer has indicated that consumption of red meat is “probably carcinogenic” to humans, whereas processed meat is considered “carcinogenic” to humans.