Wednesday April 3rd. Dr. Sofia Ahmed discussed the role of fructose in CKD. She began by discussing the increasing prevalence of CKD and ESRD in the general population, then focusing on the increasing caloric intake in the general population – specifically due to sugar and fat. Of the sugars, this seems to be largely related to high fructose corn syrup (HFCS) which actually has both fructose and glucose in it! One thought is, as she explained it, high fructose leads to an increase in uric acid which may lead to CKD. She next ran through a number of studies showing that a high intake of HFCS (largely from sweetened beverages) is associated with high uric acid, an increase in systolic blood pressure, and an association with CKD – although in that particular study – not incident hyperuricemia or CKD (Bombock et al. KI 2010). Other studies revealed more weight gain from HFCS compared to glucose possibly by altering leptin levels. A meta-analysis published in the Annals of Internal Medicine 2012, however, revealed no difference between fructose and glucose on weight gain when restricted to isocaloric studies. She also quoted studies where weight gain/HTN risk does not seem as significant if fructose was obtained from natural sources like fruit. Animal studies however show that industrial strength intake of pure fructose is indeed nephrotoxic.
Her bottom line:
Animal studies show that high fructose diets are nephrotoxic. Diets high in HFCS are increasing as is CKD, but so is intake in all sugars and fats. Therefore, consumption of fructose is probably ok – when taken in moderation. –by Dr. Vinay Nair, eAJKD Advisory Board member.
Dr. Daniel Weiner, AJKD Deputy Editor, moderated the session on CKD management and had the following comments on this talk: Dr. Ahmed from Calgary gave an outstanding talk on fructose. Clearly bad to give massive amounts to rats. In people, the jury is out but the data seem to favor at most moderate intake and suggest that naturally occurring fructose (ie, in 100% orange juice) may not be particularly harmful, perhaps because the accompanying food (ie, fruit) has positive effects and, importantly, little sodium!
Check out more eAJKD coverage of the NKF’s 2013 Spring Clinical Meetings!