A literature analysis supported links between  sugar  intake and both total energy intake and body weight gain , and between sugar intake and blood triglycerides independently of total energy intake .
The effects of sugar on blood triglycerides were shown to be mediated by the fructose component of sucrose and were observed with an intake of fructose > 50 g/day .
In addition , prospect i ve cohort studies showed associations between sugar intake and the risk of diabetes/insulin resistance , cardiovascular diseases , NAFLD , and hyperuricemia .
Grape Polyphenols Prevent Fructose-Induced Oxidative Stress and Insulin Resistance in First-Degree Relatives of Type 2 Diabetic Patients
OBJECTIVE To assess the clinical efficacy of nutritional amounts of grape polyphenols ( PPs ) in counteracting the metabolic alterations of high-fructose diet , including oxidative stress and insulin resistance ( IR ) , in healthy volunteers with high metabolic risk . RESEARCH DESIGN AND METHODS Thirty-eight healthy overweight/obese first-degree relatives of type 2 diabetic patients ( 18 men and 20 women ) were r and omized in a double-blind controlled trial between a grape PP ( 2 g/day ) and a placebo ( PCB ) group . Subjects were investigated at baseline and after 8 and 9 weeks of supplementation , the last 6 days of which they all received 3 g/kg fat-free mass/day of fructose . The primary end point was the protective effect of  grape PPs  on fructose-induced IR . RESULTS In the PCB group , fructose induced 1 ) a 20 % decrease in hepatic insulin sensitivity index ( P < 0.05 ) and an 11 % decrease in glucose infusion rate ( P < 0.05 ) as evaluated during a two-step hyperinsulinemic-euglycemic clamp , 2 ) an increase in systemic ( urinary F2-isoprostanes ) and muscle ( thiobarbituric acid – reactive substances and protein carbonylation ) oxidative stress ( P < 0.05 ) , and 3 ) a downregulation of mitochondrial genes and decreased mitochondrial respiration ( P < 0.05 ) . All the deleterious effects of fructose were fully blunted by grape PP supplementation . Antioxidative defenses , inflammatory markers , and main adipokines were affected neither by fructose nor by grape PPs . CONCLUSIONS A natural mixture of grape PPs at nutritional doses efficiently prevents fructose-induced oxidative stress and IR . The current interest in grape PP ingredients and products by the global food and nutrition industries could well make them a stepping-stone of preventive nutrition
A literature analysis supported links between  sugar  intake and both total energy intake and body weight gain , and between sugar intake and blood triglycerides independently of total energy intake .
The effects of sugar on blood triglycerides were shown to be mediated by the fructose component of sucrose and were observed with an intake of fructose > 50 g/day .
In addition , prospect i ve cohort studies showed associations between sugar intake and the risk of diabetes/insulin resistance , cardiovascular diseases , NAFLD , and hyperuricemia .