The effects of dietary sugar on risk factors and the processes associated with metabolic disease remain a controversial topic, with recent reviews of the available evidence arriving at widely discrepant conclusions.
There are many recently published epidemiological studies that provide evidence that sugar consumption is associated with metabolic disease. Three recent clinical studies, which investigated the effects of consuming relevant doses of sucrose or high-fructose corn syrup along with ad libitum diets, provide evidence that consumption of these sugars increase the risk factors for cardiovascular disease and metabolic syndrome. Mechanistic studies suggest that these effects result from the rapid hepatic metabolism of fructose catalyzed by fructokinase C, which generates substrate for de novo lipogenesis and leads to increased uric acid levels. Recent clinical studies investigating the effects of consuming less sugar, via educational interventions or by substitution of sugar-sweetened beverages for noncalorically sweetened beverages, provide evidence that such strategies have beneficial effects on risk factors for metabolic disease or on BMI in children.
The accumulating epidemiological evidence, direct clinical evidence, and the evidence suggesting plausible mechanisms support a role for sugar in the epidemics of metabolic syndrome, cardiovascular disease, and type 2 diabetes.