The study, carried out by Harvard University, claimed that women with diets high in saturated fats had worse memories than those who ate diets high in monounsaturated fats, leading the international press to link meat consumption with Alzheimer’s and recommend that people swap red meat and butter for olive oil and avocados.
However, the research has been met with criticism by some UK nutritionists, who point out that it is based on epidemiology, which cannot be be used to effectively demonstrate cause and effect.
Nutritionist and obesity campaigner Zoë Harcombe told Globalmeatnews.com:
“This is association, not causation. The women who performed better on some random tests may have worn brown tights and those who performed less well black tights. We can no more say that wearing black tights raises Alzheimer’s risk than any component of these women’s diets.
“All these studies ever do is observe two things together. It is the most common bad science error that is ever made. The way they jump to causation and the way the media headlines jump to causation is just ignorant.”
She added that the scientists had failed to consider other dietary factors which could have affected the results. “I have no doubt that I could find a much stronger association between people who eat refined carbohydrates and memory performance, but that is not what they set out to prove,” she said.
Saturated fat myth
Even if the association in the Harvard study had any relevance whatsoever, Harcombe pointed out that meat is actually lower in saturated fat then some of the alternatives recommended.
“Not that any fat is better or worse than the other, but of the three fats – saturated, monounsaturated and polyunsaturated – the single largest in meat tends to be monounsaturated,” she said.
“In the rare circumstances when it actually is saturated, the two unsaturated fats added together still exceed the saturated proportions. Most red meat is about 40% saturated, 60% unsaturated. White meat is about equal in each of the three fats.”
According to data on the US Department for Agriculture, 100g of pork has 75g of water, 21g of protein, 2.3% unsaturated fat (1.8g monounsaturated and 0.5g polyunsaturated) and 1.5g saturated fat. The same quantity of olive oil, in comparison, has 13.8% of saturated fat, 73g of monounsaturated fat and 10.5g of saturated fat.
“There is more saturated fat in a tablespoon of olive oil than in 100g of pork chops,” said Harcombe.
She warned it would also be impossible for people to swap one type of fat for another, because all three fats are found in foods that contain fat, and that attempting to do so could lead to other nutritional problems.
“The authors of this paper need to explain exactly how they think we can increase one type of fat at the expense of another while making no other changes whatsoever,” she said.
“If you do what they are advising in the study, which is to ditch red meat in favour of olive oil, you increase calories sevenfold, increase saturated fat ninefold, increase monounsaturated fat 40-fold, increase polyunsaturated fat 22-fold, and lose all the vital protein, minerals and B vitamins.”
The Harvard study looked at the results from 6,000 women, aged over 65, who carried out a series of mental tests over four years, while also answering questionnaires about their diet and lifestyle.