Gene clue to sweet cravings

Canadian researchers, based at University of Toronto, have discovered a genetic variation which may help to explain why some people have a sweet tooth, causing them to consume more sugary foods and drinks in their diet. The findings, published online last week in the journal Physiological Genomics, suggest that carriers of the so-called GLUT2 gene variant consistently consume more sucrose (table sugar), fructose (simple sugar) and glucose than those without the variation, regardless of gender or age.

'We have found that a variation in the GLUT2 gene is associated with a higher intake of sugars among different populations. These findings may help explain some of the individual variations in people's preference for sugary foods. It's especially important given the soaring rates of obesity and diabetes throughout much of the world', said Dr Ahmed El-Sohemy, who led the study.

The researchers examined the diets of two distinct groups of people - one which comprised 127 overweight or obese 42-75 year-olds with type 2 diabetes, and the other which comprised 720 healthy 20-29 year-olds. Examining the genotype of these two groups revealed that among the older group, carriers of the GLUT2 gene variant ate an average of 30 grams more sugar per day, where as among the younger group, carriers ate an average of 20 times more sweets and five times more sugary drinks per day.

The GLUT2 gene is known to play a role in regulating how much glucose enters into cells. These findings highlight the complexity of diseases such as obesity and diabetes, which result from a combination of both environmental and genetic factors, said Diane Finegood, head of nutrition, metabolism and diabetes with the Canadian Institutes of Health Research, speaking to the Toronto Star.

'They are identifying a potentially important connection between the brain and behaviour or the stimulus for behaviours,' Finegood said.' It helps to highlight for the public that there are important connections between the genes and our environments and our behaviour'.