Do Fructose-Containing Sugars Lead to Adverse Health Consequences? Results of Recent Systematic Reviews and Meta-analyses

Abstract

Sugars have replaced fat as the dominant public health nutrition concern. A fructose-centric view of cardiometabolic disease has emerged whereby fructose-containing sugars are thought to have deleterious effects on body weight, fasting and postprandial blood lipids, glycemia, blood pressure, uric acid, and markers of nonalcoholic fatty liver disease. Long-term prospective cohort studies have not supported these associations when assessing the relation between total fructose-containing sugars at any amount of intake and incident cardiometabolic disease. Conversely, a consistent signal for harm has been reported for sugary beverages when comparing the highest with the lowest intakes. These associations, however, do not hold at moderate intakes, which are more reflective of real-world intakes, are subject to important collinearity effects, and have small risk estimates with modest population-attributable risk fractions. Higher-level evidence from controlled feeding trials shows that fructose-containing sugars in either liquid or solid form have adverse cardiometabolic effects only when they supplement diets with excess calories compared with the same diets without the excess calories. In the absence of harm when fructose-containing sugars are exchanged for other sources of carbohydrate under energy-matched conditions, excess calories appear to be the dominant consideration. Like with the earlier fat story, it is difficult to separate the contribution of fructose-containing sugars from that of other sources of excess calories in the epidemic of obesity and cardiometabolic disease. Attention needs to remain focused on reducing the overconsumption of all caloric foods associated with obesity and cardiometabolic disease, including sugary beverages and foods, and promoting greater physical activity. Adv Nutr 2015;6(Suppl):504S-11S.

Determining the contribution of a high-fructose corn syrup formulation to hepatic glycogen synthesis during ad-libitum feeding in mice

“…Perhaps the largest discrepancy between our rodent model and humans that are categorized as high sugar consumers is that the sugar load, its caloric contribution to total energy intake, and the extent of caloric excess relative to the control diet, is almost certainly far greater for the mouse compared to the human. Therefore, it is possible that some of our metabolic observations may reflect excessive caloric intake rather than the effects of the individual sugars per se 25 . Our methodology can nevertheless be translated to humans by integrating 2 H 2 O and 13 C-sugar administration with a noninvasive “chemical biopsy” of hepatic UDP-glucose 2 H and 13 C enrichments by ingestion of Paracetamol and analysis of urinary Paracetamol glucuronide 26 .…”

Association of dietary macronutrient composition and non-alcoholic fatty liver disease in an ageing population: the Rotterdam Study

“…Although the general assumption is that fructose intake harms the liver, evidence for this assumption is indeterminate 39. In most studies, it is difficult to separate the contribution of fructose-containing sugars from that of other dietary factors, such as origin of food item, energy intake and overall dietary quality 13. This lack of clarity is supported by experimental studies showing that isocaloric carbohydrate intake was not associated with steatosis, but rather with amount of calories 40 41.…”

Sugars and Health Controversies: What Does the Science Say?

“…Recent systematic reviews and meta-analyses as well as multiple RCTs have suggested that there is nothing unique with regard to sugar consumption and its health consequences, provided that sugar is substituted isocalorically for other carbohydrates and consumed within the normal range of human consumption (15). Some questions still remain from research trials in which fructose-containing sugars were substituted in a hypercaloric fashion (added to an already eucaloric diet).…”

“…These studies are summarized in detail in the article by Sievenpiper et al (15) in this supplement issue. In this article we will summarize some of the key studies that were published during this period of time.…”