Eur J Clin Nutr (2018) 72:1717-1723; https://doi.org/10.1038/s41430-018-0134-x — Rodrigues N, Peng M, Oey I, and Venn BJ. — Download PDF —
- To assess the effects of partial replacement of sucrose with fructose on serum glucose, uric acid and blood pressure.
- Fructose has been shown to adversely affect plasma lipids and may predispose excessive consumers to the deposition of visceral adipose tissue, dyslipidaemia and insulin insensitivity.
- Epidemiological studies have linked increasing added fructose consumption with metabolic disorders such as obesity, diabetes, metabolic syndrome, non-alcoholic fatty acid liver disease and cardiovascular diseases.
- In apparent contrast, the European Food Safety Authority (EFSA) has permitted a health claim (ID558) to be placed on foods and beverages in which fructose partially replaces sucrose, potentially raising the intake of fructose within those populations.
- The rationale for this claim is a reduction in postprandial glycaemic response, as substantiated from studies in which 100% fructose was compared to 100% sucrose or to 100% glucose. However, the EFSA allows the claim on food or beverage products sweetened predominantly with sucrose but with a minimum fructose content of 30% of the total added sugar content.
- The postprandial glycaemic response to beverages with such blends of sugars has never been tested so the practical implication of this health claim in the context of acute glycaemic response is still unclear. It is also unclear how fructose replacement in beverages will affect circulating concentrations of uric acid and blood pressure.
- Investigators conducted a randomized, crossover, double-blinded trial in which participants were given the following sugar-sweetened beverages: 50 g sucrose as a reference beverage tested on two occasions as a duplicate test, 33.5 g sucrose and 16.5 g fructose (67%S:33%F), 25 g sucrose and 25 g fructose (50%S:50%F) and 16.5 g sucrose and 33.5 g fructose (33%S:67%F). All beverages were designed to contain sugar concentration of 10.9%, which is commonly used in commercially manufactured sugar-sweetened beverages.
- On test days, participants reported after a 10-h overnight fast and ingested the beverages within 15 min. Blood draws were taken at baseline and thereafter at 15, 30, 45, 60, 90 and 120 min. To describe the fasting blood glucose and uric acid status of the participants, values of the five testing days were averaged for each person and from these, group mean fasting serum glucose and uric acid baseline values were calculated.
- Height, weight and blood pressure measurements were collected and participants completed questionnaires about demographic information including age, sex, self-identified ethnicity, soft drink consumption habits and smoking status.
- There was a significant trend for a reduction in blood glucose response as the proportion of fructose increased in the test drinks.
- The partial replacement of sucrose with fructose resulted in a clear increase in uric acid concentration with some levels exceeding the hyperuricaemic threshold throughout the postprandial period.
- There were no statistically significant differences in blood pressure readings when comparing the fructose-substituted drinks to the sucrose reference over the postprandial period.
- Partial substitution of sucrose with fructose has a lowering effect on glycaemic response.
- Despite the finding that circulating uric acid concentrations increase acutely following fructose consumption, the clinical implications are unclear.
- Though data in the current study did not indicate a differential in blood pressure change over time between the fructose-substituted and the sucrose reference beverage, it is possible that the amount of fructose in the fructose-substituted drinks was insufficient to generate differences in blood pressure.
- A more comprehensive appraisal as to whether sugary foods and beverages should bear health claims may be warranted. Although a modest reduction in postprandial glycaemia might be achieved, the wider implications of consuming sugary foods and beverages including excess energy intake and the issue of fructose and uricaemia need to be considered.
Points to Consider
- The results of this study are limited to an assessment of the acute effects of partial replacement of sucrose with fructose. The chronic, long-term effect of the partial replacement and the health implications are unknown.
- This sample was comprised of healthy participants. Therefore, the findings of this study may not be generalizable to participants with compromised glucose tolerance or uric acid metabolism.