Inside Health
Is it safe to eat red meat once again, asks Professor Harry Burns
For some time, people have been encouraged to limit their intake of red and processed meat in the belief that it would reduce their risk of heart attack, stroke, diabetes and cancer.
New research, however, calls this advice into question. One study reviewed and reanalysed 100 projects which assessed risk of red meat in more than six million participants. The overall conclusion was that reducing meat consumption by about three servings per week probably results in only small reductions in risk of serious health problems over long periods. Out of every 1,000 people studied, the reduction in risk of death over a ten-year period was less than one per cent. In addition, the researchers concluded that the certainty of the evidence for even such a small effect was low. Despite these conclusions, public health agencies continue to advise that reducing red meat consumption is beneficial to health. Understandably, people are frustrated at getting such contradictory advice.
The problem is that it is extremely difficult to do dietary studies with any degree of confidence. It is hard to assess behaviour. The information about diet in these studies was selfreported. People were asked how often they ate red or processed meat. They may have misjudged the frequency with which they ate it, or, knowing that frequent consumption was not recommended, they may have been reluctant to tell the truth.
High meat consumption and increased risk of ill health may be associated with each other but the meat consumption might not be the direct cause of the ill health. In the 1960s, the government in Finland concluded that high male death rates from heart attack were due to high levels of fat in the diet. They took radical steps to encourage a switch from fatty foods to fruit and vegetables and, over the next few decades, the incidence of heart-related deaths declined significantly. Everyone congratulated the Finns for fixing the problem. However, in the 1990s we realised that the rate of decline in heart attacks in Scotland was exactly the same as in Finland. The Finns took radical action to reduce fat consumption while the Scots were inventing the deep-fried Mars Bar and both countries saw the same decline in male heart attack rates!
The real cause of the decline was probably the fact the men began to give up smoking in the 1960s. Dietary change and reduced heart deaths in Finland were associated with each other but one was not the cause of the other. People who eat a lot of meat might also smoke or drink more. It might not be the meat that causes the increased risk, it might be something else meat eaters do. Association does not prove causation.
However, there is another reason why we should consider the impact of agriculture on well-being. A couple of weeks ago, I was in New York and found myself in the middle of a large crowd of schoolchildren walking across the Brooklyn Bridge. They were on their way to join 200,000 others in listening to Greta Thunberg speak about the climate emergency. It was an impressive sight and it made me think. Meat and dairy production is estimated to be responsible for 25-50 per cent of gases implicated in climate change. Environmental scientist Joseph Poore of Oxford University suggests that “a vegan diet is probably the single biggest way to reduce your impact on planet Earth... It is far bigger than cutting down on your flights or buying an electric car”. Perhaps I’ll forgo that fillet steak I was planning for tonight, after all!