Why diabetes is so high in South Asians

Medical statistics in the UK have persistently shown that diabetes, heart disease and other related conditions grouped together as the metabolic syndrome are far more common amongst people from the South Asian sub-continent than in other communities. Most of the speculation for the reasons for this has ascribed it to a diet full of sweet and fried food combined with a lack of exercise, though why the effects of those shortcomings (which are common in other communities too) should apparently have more negative effects in the South Asian community has never been clear to me. Apparently, central obesity, tums and bums in other words, is more common in South Asians. What's more, the extent of central obesity is more or less in direct proportion to the likelihood of diabetes and heart disease. I got the explanation for all this in Chennai from Dr Ramachandran, who probably knows more about diabetes than anybody else in the world.

The statistics in India are even more striking. One in five Indians has diabetes and in the urban areas and the middle classes the proportions are even higher. Something similar has been noted in communities in the Gulf States. Richer, more comfortable lifestyles, it would seem, have their cost, but why should the cost, at least in diabetes, be so strikingly frequent in some communities more than others. The answer is climate-related. In hot countries the problems of food storage are extreme. Sir Francis Bacon tried to prove that freezing a chicken would preserve it. He was right, but the attempt to stuff the chicken with snow gave him such a bad bout of influenza that he died in the pursuit of knowledge. As a result, people whose genetic make-up has evolved in cold, northern countries are less good at storing foods in their bodies. They have less need to do so. The beneficial effects of a cold climate have meant that food is more evenly consumed through the seasons. In hot countries food was plentiful after rainy seasons and scarce in dry seasons. As a result the metabolism of the denizens of hot countries developed the ability to better store food and therefore to go for longer with less food if need be. The same chemical processes that go into storing food in our bodies are also the ones, when food is consistently in excess, which produce diabetes and its metabolic cousins. Now that food, at least for the urban middle classes in India and for almost everyone in the Gulf states, is in consistent and plentiful supply, no famine comes to pass, only constant feast. We Indians eat too much for a while and then, instead of eating less for a while, we continue to eat too much. The result is diabetes and heart disease. Geneticists argue that the rate of human evolution has slowed and may even have been stopped altogether because of better medicines, changes in philosophical and social attitudes to people with congenital disabilities and a reduction in the wholesale risks to groups of humans such as famine, flood and pestilence. So whatever genetic predilections some communities have are likely to remain.

What then is to be done? Well, the increased risk of suffering from the detriments of the metabolic syndrome remain and persist. They can be partially ameliorated by less red meat, less alcohol and more exercise. But that will postpone the metabolic effects, not remove them entirely. The day of shuffling off this mortal coil can be postponed, not indefinitely avoided.