Clinical Experts: Lower Sugar Allowance to Prevent Diabetes

Limiting added sugars could be among the most effective strategies for reducing the prevalence of type 2 diabetes, according to clinical experts writing in Mayo Clinic Proceedings.

Based on their results, the experts challenged current dietary guidelines, which allow added sugars to comprise up to 25% of total daily calories, and they recommended drastic reductions in sugar consumption levels.

“At current levels, added-sugar consumption, and added-fructose consumption in particular, are fueling a worsening epidemic of type 2 diabetes,” said lead study author James J. DiNicolantonio, PharmD, in a press release. “Approximately 40% of US adults already have some degree of insulin resistance with projections that nearly the same percentage will eventually develop frank diabetes.”

According to the authors, whose affiliations include Montfiore Medical Center and Saint Luke’s Mid America Heart Institute, evidence from various clinical trials and studies suggest that added sugars, particularly those containing fructose, disturbs the metabolism and contributes to global insulin resistance in a more pronounced way than other dietary sugars.

Several clinical trials demonstrated increases in fasting insulin, fasting glucose, and insulin/glucose responses to a sucrose load associated with fructose or sucrose. Such increases were not present in trials examining glucose or starch, the authors noted.

“This suggests that sucrose, in particular the fructose component, is more harmful compared to other carbohydrates,” Dr. DiNicolantonio said.

Meanwhile, recent trial data suggests that replacing glucose-only starches with fructose-containing table sugar results in significant adverse metabolic effects.

According to the 2010 Dietary Guidelines for Americans, it is acceptable for some individuals to consume up to 19% of their daily calories from added sugars. In addition, the Institute of Medicine allows up to 25% of total caloric consumption from added sugars.

In contrast, the World Health Organization recommends that added sugars comprise no more than 10% of an individual’s daily caloric intake and has proposed lowering that level to 5% or less, which is more aligned with the authors’ beliefs.

Dr. DiNicolantonio and his colleagues stressed that the fructose found in fruits and vegetables poses no harm to human health and is likely to protect against diabetes and other cardiometabolic problems. As a result, the authors proposed replacing foods that contain added sugars and fructose with fruits and vegetables.