Studies have already shown that added sugars can be a major contributor to the prevalence of pre-diabetes and diabetes, but researchers are challenging current food guidelines, proposing that less than the recommended is ideal for optimum health.
According to James DiNicolantonio, a cardiovascular researcher for Saint Luke's Mid America Heart Institute and lead author for a study published in the journal Mayo Clinic Proceedings, current consumption of added sugars, most especially those containing fructose, is worsening the type 2 diabetes epidemic. In fact, about 40 percent of adults are already harboring some level of insulin resistance and it is estimated that the same number will eventually go on to develop diabetes.
Researchers explained that the net result of consuming too much fructose is a massive deviation in both global insulin resistance and overall metabolism. Sugars that don't contain fructose don't seem to be as harmful as their fructose-containing counterparts, as shown by some clinical trials where isocaloric exchange involving fructose leads to higher fasting glucose, fasting insulin and glucose/insulin responses.
"This suggests that sucrose (in particular the fructose component) is more harmful compared to other carbohydrates," added DiNicolantonio.
Dietary guidelines released in 2010 say up to 19 percent of calories from sugars is allowable, while the Institute of Medicine bumps this figure up to 25 percent. The World Health Organization, however, recommends that 10 percent of calories at the most should come from added sugars, even proposing that the number be reduced to 5 percent and less.
This is in line with what researchers are suggesting, similar to the recommendations from the American Heart Association, which stipulates women should consume no more than 24g, or six teaspoons, of sugar in a day while men have a bit more leeway at 36g, or nine teaspoons, every day.
What about naturally occurring fructose?
Researchers recommend that people should load up on fruits and vegetables. The sweeter varieties contain higher levels of fructose but these naturally added sugars are not so bad considering the overall benefits that eating fruits and vegetables will bring. Instead, people should watch out more for added sugars in processed food.
DiNicolantonio and colleages also suggest industry incentives to encourage food manufacturers from adding sugars into their products.
In the United States alone, 29 million adults are living with type 2 diabetes while another 86 million are straddling the pre-diabetes border. The number of people affected by type 2 diabetes in the world was estimated to have more than doubled from 1980 to 2008, growing from 153 million to 347 million.