Opinion: Nutrionist ostracised by scientific community

John Yudkin and his book, Pure, White and Deadly.
John Yudkin and his book, Pure, White and Deadly.

In the seventies animal fat was denounced as the “new tobacco”, later followed by salt – also the “new tobacco”.

Now we have sugar in the headlines as the new demon substance, deadlier than fags. Actually, this is not quite accurate.

In 1972, a London University biochemist and nutritionist, John Yudkin, published a book, Pure, White and Deadly that was widely denounced and it led, ultimately, to the end of his academic career. In his book Yudkin challenged the then current orthodoxy that fat is public enemy number one in the world of cardiovascular health and suggested that there was a much closer correlation between sugar and heart disease than fat. The vested interests went to work on him – the writers and publishers of books advocating low-fat diets, the sugar industry, and food manufacturers who were making a mint selling “low-fat” versions of standard products. They are with us to this day.

Yudkin argued that sugar raised blood fat levels in laboratory animals and interfered with appetite in a way that led to over-eating. He reasoned that we have been consuming fat for centuries whereas sugar until the middle of the 19th century had been a luxury item available to very few. In the sixties and seventies the food industry, trying to meet popular demand for “healthy” low fat food discovered that reducing the fat content resulted in products that tasted nothing so much as cardboard if they tasted of anything. Fat, as we all know, is tasty. The substitute the settled on was sugar.

The quantity of sugar in even the most unlikely foods, when expressed in teaspoon measures, is astonishing. In can of Coca Cola, for example, which we all know is very sweet, there is the equivalent of six teaspoon loads. Even the most enthusiastic sweet tea drinkers would regard such a dose of sugar as a bit much. It is also there in foods that we do not think of as sweet – bread, for example.

Yudkin was marginalised and ostracised by the scientific community. Academic journals refused to accept his research papers, invitations to conferences were withdrawn and his internationally renowned department at Queen Elizabeth College, London, suffered. The British Sugar Bureau described his work as “science fiction”. Many of the professional bodies were funded by the sugar industry, among them Tate & Lyle. He was what today might have been called a “fat denier”.

Since then things have changed. Hormones, unheard of in Yudkin’s time, which support Yudkin’s theories have been discovered, his book has been republished and he is being rehabilitated. An American paediatric endocrinologist, Robert Lustig, is one of his champions. Sugar consumption is up 30 per cent since 1990, obesity in the UK is 10 times what it was when Yudkin wrote his book.

In favour of sugar, it has been discovered that sugar-free mixers have an unexpected side effect. If you drink vodka and diet lemonade – or gin and tonic, whatever is your pleasure – your breathalyser reading will be 25% higher than if you had used regular mixers. Now I know why my late mother-in-law, Margaret, who was a doctor after all, always insisted on having sugar lumps in her Champagne cocktails on Christmas morning. Sensible woman. But no sugar in her tea.

Speaking of doctors in the family, we had one as a weekend guest and over dinner, in an attempt to demonstrate what I thought was my cleverness, I recounted the annual medical finding that I had lost two inches over twelve months. I was told that not only is it possible, but it is commonplace to lose almost as much height in a single day. It goes like this: during the day as we walk (upright, no knuckles trailing) the spaces between the bones of the spine get compressed and we lose height. At night, lying horizontal, the spine spreads again and, hey presto, we are taller. As I have always wanted to be a six-footer, I wondered if I lay on a bed for two or three days I would on rising achieve this. The medical man looked at me as though I am several annas short of a rupee. I thought, but did not say, that doctors don’t know everything and decided to give it a try. I’ll keep you posted.

There were no awkward revelations of personal medical problems over dinner; doctors hate that. Even though it is a fascinating story, I managed to keep my haemorrhoids under wraps.