Dietary Sugars Directly Effect Cardiometabolic Risk

Dietary sugars are thought to be a cause of obesity, chronic disease, and a variety of cardiometabolic risk factors, but other than body weight, little hard evidence of a causal relation between sugars and risk factors has been found.

Researchers, led by Lisa Te Morenga, PhD, of the Department of Nutrition at the University of Otago in New Zealand, conducted a systematic review and meta-analysis of all English-language studies comparing the effects of higher versus lower added sugar consumption blood pressure and lipids, finding that dietary sugars have significant influence on blood pressure and serum lipids that is independent of effects of sugars on body weight.

Compared to lower sugar intakes, high sugar compensation significantly raised triglyceride concentrations, total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol.

“Although the effects of sugars on blood pressure and lipids are relatively modest, our findings support public health recommendations to reduce added sugars in our diets as one measure that might be expected to reduce the global burden of cardiovascular disease,” Te Morenga said in a statement. “Our latest study did find significant effects of sugars on lipids and blood pressure among these types of energy-controlled studies, suggesting that our bodies handle sugar differently than other types of carbohydrates.”

The investigators searched several databases including Embase, Scopus, OVID Medline, and the Web of Science through August 2013 and identified studies with a trial duration of at least 2 weeks that reported intake of free sugars and at least 1 lipid or blood pressure outcome. Data were pooled using inverse-variance methods and random-effects models. Of 11,517 trials identified, 37 reported lipid outcomes and 12 reported blood pressure outcomes.

Although much of the research the authors looked at was funded by the food industry, there was still a positive association between sugars and cardiometabolic risk factors, which surprised Te Morenga.

“In subgroup analyses we showed that by excluding the trials funded by the food/sugar industry, we found larger effects of sugar on lipids and blood pressure,” she said.

The study was published online in the American Journal of Clinical Nutrition ahead of print.