The bad science of food

You can’t trust scientistry. You simply can’t. Think about how many times, over the last few DECADES, you were told that eating fat and butter and cream and cheese was bad for you. Remember how fettucini alfredo was once called “a heart attack on a plate?” Then read this belated mea culpa from a doctor who admits that he has been giving out worse than useless advice to his patients for years.

Milk, cheese, butter, cream – in fact all saturated fats – are bad for you. Or so I believed ever since my days as a medical student nearly 30 years ago. During that time I assured friends and family that saturated fat would clog their arteries as surely as lard down a drain. So, too, would it make them pile on the pounds. Recently, however, I have been forced to do a U-turn. It is time to apologise for all that useless advice I’ve been dishing out about fat.

The roots of our current confusion lie in a paper by an American scientist called Ancel Keys in 1953. It covered the increasingly common problem of clogged arteries. Keys included a simple graph comparing fat consumption and deaths from heart disease in men from six different countries. Americans, who ate a lot of fat, were far more likely to have a heart attack than the Japanese, who ate little fat. Case solved. Or was it?

Other scientists began wondering why Keys chose to focus on just six countries when he had access to data for 22. If places like France and Germany were included the link between heart disease and fat consumption became much weaker. These were, after all, countries with high fat consumption, but relatively modest rates of heart disease. In fact, as a renowned British scientist called John Yudkin pointed out, there was actually a much stronger link between sugar consumption and heart disease.

But Yudkin’s warnings about sugar were denounced by a fellow scientist as ‘nothing more than scientific fraud’. He was, as one of his colleagues colourfully put it, ‘thrown under a bus’.

Meanwhile, the war on fat gradually gained momentum, to the extent that by the time I reached medical school in the Eighties, there was no mention of Yudkin’s findings. People were cutting down on dairy products and switching to sugary carbohydrates and vegetable oils. This, it turns out, was a mistake. To turn vegetable oil into margarine, manufacturers used a process called hydrogenation (gas pumped through oil at high temperature), which produces trans fats. These are the Darth Vader of the fat world: good fats turned bad.

Unlike saturated fats, there is clear evidence that trans fats damage your heart. They were found in most shop-bought biscuits and cakes until they were removed in 2007.

Think about how many people have suffered ill effects from eating a bad, science-recommended diet. The amazing thing is that this doctor clung to what he “knew” even though “I put on over two stone, despite regular exercise. My cholesterol soared past the healthy range and two years ago I discovered I was borderline diabetic.”

Observation is an important part of the scientific process. Not publishing. Not peer review. And it is eminently clear that too few people in the scientific and medical communities are observing anything.