`We've strong evidence that eating sugar contributes to heart disease'

KIMBER STANHOPE, nutritional biologist at the University of California, US, has carried out experiments on people comparing health effects of fructose with those of glucose and high fructose corn syrup, which is part glucose and part fructose. In an interview to ARCHANA YADAV she shares the findings. Excerpts Your study shows fructose has unique effects on the body. Are these significant enough to cause metabolic diseases in the long term? To prove that sugar is causing a particular disease we have to rely on diet intervention studies. When you do such a study the best you can look at is a risk factor because nobody ethically can do a study in which the intention is to cause human subjects to develop a disease. Our first study, published in 2009, suggests compared to glucose, fructose causes increased lipid levels, increased fat-making in the liver and it reduces insulin sensitivity. It also appears to have a unique effect by which the excess fat gained during the consumption of fructose-sweetened beverage gets deposited in visceral adipose. Now visceral adipose is the fat contained within the abdominal cavity and that fat is more associated with metabolic disease risk factors than the fat deposited under the skin. Since then we have shown that when younger, healthier subjects eat high levels of fructose or high fructose corn syrup, their lipid factors rise in two weeks. Is it okay to consume lots of carbohydrates if one eliminates sugar? That is difficult to know for sure because at this point many of the studies that suggest carbohydrate consumption is related to metabolic disease did not separate the effects of sugar versus the effects of bread, rice and grain. My subjects consume white bread, white rice, white pasta, not whole grain. When I take away those carbohydrates and instead add the sugar, I see increased risk factors. My data shows very clearly sugar is a bigger problem compared to white bread, pasta and rice. Is sugar an independent risk factor for heart disease? If we put together population studies that show associations between sugar consumption and heart disease, and look at the diet intervention studies that show increased risk factors when we replace the food that people eat with sugar, I'd say we have a very strong body of evidence that sugar consumption contributes to heart disease. Some of that data suggests it is independent of weight gain. My data certainly suggests there is increase in risk factors even if subjects do not gain weight. But I would like to do a study where subjects are provided with meals (with either high or low amounts of sugar) that contain exactly their energy requirement, so none gains weight. That would be the definitive evidence.