After just 9 days of reducing their intake of added sugar, children with chronic metabolic diseases such as high cholesterol and high blood pressure were able to reverse their symptoms, according to a study by scientists at the University of California, San Francisco, and Touro University California in Vallejo. The findings appeared online in the October 27 edition of the journal Obesity (doi: 10.1002/oby.21371).
“This study definitively shows that sugar is metabolically harmful not because of its calories or its effects on weight; rather sugar is metabolically harmful because it’s sugar,” said lead author Robert Lustig, MD, MSL, pediatric endocrinologist at UCSF Benioff Children’s Hospital, in a press release. “This internally controlled intervention study is a solid indication that sugar contributes to metabolic syndrome, and is the strongest evidence to date that the negative effects of sugar are not because of calories or obesity.”
Jean-Marc Schwarz, PhD, of the College of Osteopathic Medicine at Touro University California and senior author of the paper, added, “I have never seen results as striking or significant in our human studies; after only nine days of fructose restriction, the results are dramatic and consistent from subject to subject. These findings support the idea that it is essential for parents to evaluate sugar intake and to be mindful of the health effects of what their children are consuming.”
In the study, 43 children aged 9–18 who were obese and had at least one other chronic metabolic disorder, such as hypertension, high triglyceride levels or a marker of fatty liver, were given 9 days of “kid-friendly” meals, snacks and beverages that restricted sugar but substituted starch to maintain the same fat, protein, carbohydrate and calorie levels as their previously reported home diets.
After just 9 days on the sugar-restricted diet, virtually every aspect of the children’s metabolic health improved, including diastolic blood pressure, tri-glycerides, LDL cholesterol and liver function markers. Fasting blood glucose went down by 5 points, and insulin levels were cut by one-third.
“All of the surrogate measures of metabolic health got better, just by substituting starch for sugar in their processed food—all without changing calories or weight or exercise,” Lustig said. “This study demonstrates that ‘a calorie is not a calorie.’ Where those calories come from determines where in the body they go. Sugar calories are the worst, because they turn to fat in the liver, driving insulin resistance, and driving risk for diabetes, heart and liver disease. This has enormous implications for the food industry, chronic disease and health care costs.”