The latest news about the fat gene, and how we can fight it.
Philadelphia- These days, we look to genetics to explain almost everything that can go wrong with people, from cancer to mental illness to poor school performance. Obesity is no exception to this rule – scientists have devoted lots of time and research money to discovering genes that can explain why some people are bigger than others.
Over the years, this search has been fairly successful. A few years back, for example, scientists identified a variant of the FTO gene that was shown to be related to a higher risk of obesity. According to several large-scale studies, people with a particular form of the FTO gene weighed, on average, several kilograms more than people with a different form of it, and had a much higher risk of obesity.
The discovery of this so-called obesity gene was very depressing for a lot of people. It seemed to imply that, for the heavyset, there was nothing that could be done, that genetics were destiny and that if you were meant to be fat, you would be. Especially upsetting was the news that about 65% of people of African or European descent and 45% of Asians carry some version of the FTO gene – it seemed as if most of us were doomed to chubbiness.
However, it turns out that things are not as bad as they seem. New research and emerging science suggests that having the obesity-associated variant of the FTO gene doesn’t necessarily mean that a person is destined to be overweight. In fact, even for those pre-disposed to be heavy, environmental and other factors play a major role in whether or not they are overweight. A recently published article by a group of researchers from Cambridge University, for example, offers evidence that something as simple as physical activity can suppress the effects of the obesity gene.
The Cambridge study had its origins in a number of other studies of the FTO gene and exercise, which had found contradictory evidence about the relationship between the two. In an attempt to determine exactly what effect physical activity had on people with the obesity-associated variant of the FTO gene, the Cambridge researchers reanalysed data from these other studies.
In order to isolate the effects of exercise, the researchers went back and categorised all the people in the previous studies (all of whom carried the obesity gene) into two groups – the inactive and the active, who were defined as people who got at least an hour of moderate to vigorous exercise a week. About 25% of the people in the dataset made the grade as active.
The researchers then showed that, among this group of active people, the effect of the obesity gene was reduced by about 30%. In other words, the active group was about 30% less likely to be obese than the inactive group.
Although it may not sound like much, this is a very encouraging result, especially when you consider how low the bar was set for people to be considered active – just one hour of exercise a week. This suggests that if you have the obesity gene, but you exercise for several hours a week, you can significantly reduce your chances of becoming obese and can maintain a normal waistline. The obesity gene does not necessarily control your weight – you can do things to avoid your genetic destiny.
The findings of the Cambridge study are just one more example of how our genetic code doesn’t have to spell destiny for us. While genes are important, and play a crucial role in people’s risk profiles, our actions and choices still matter and that is good news.