Study participants who consumed soda sweetened with high-fructose corn syrup experienced increased vascular resistance in the kidneys compared with participants who consumed water, according to research published in the American Journal of Renal Physiology.
Christopher L. Chapman, of the University of Buffalo, and colleagues suggested this decrease in renal blood flow may contribute to reductions in kidney function which could lead people who regularly consume such beverages to have a greater risk of developing chronic kidney disease.
They noted that while other studies have estimated the risk to be increased by 60% – with their laboratory previously observing “greater increases in serum uric acid and copeptin in healthy adults,” as well as elevated blood pressure – after soft drink consumption, “the precise mechanisms underlying these observations remain unknown.”
To further explore this area, the researchers used a cold pressor test on “healthy” adults, defined here as being physically active, non-smokers and not having any cardiovascular, metabolic, renal or neurological diseases (participants were mostly in their early 20s). According to the researchers, the cold pressor test can “elucidate the mechanisms by which segmental artery vascular resistance is augmented with soft drink consumption.”
Results showed participants who consumed 500 mL of a commercially available soft drink sweetened with high-fructose corn syrup experienced increased vascular resistance in the kidneys within 30 minutes, while those who consumed an equivalent amount of water did not have this reaction.
In addition, the researchers found “increases in segmental artery vascular resistance were exacerbated” during the cold pressor test for those who consumed soda vs. water.
Reference: American Journal of Renal Physiology
As these increases in segmental artery vascular resistance only occurred with fructose-sweetened sodas (and not with sucrose-sweetened soda, diet soda or water), they further determined the observed elevations were specifically due to the high-fructose corn syrup, as opposed to caffeine content or osmolality of the beverage.
The researchers suggested their findings “provide insight into the acute effects of soft drink consumption on renal vascular control,” while also illuminating the “responsiveness of the kidneys during a sympathetic stressor, which can be regularly encountered in activities of daily living (eg, opening a jar or walking upstairs).”
“There is much interest in renal and cardiovascular health outcomes associated with soft drink consumption,” they concluded. “Our study indicates that a soft drink sweetened with [high-fructose corn syrup] HFCS elevates vascular resistance in the kidneys and elicits a greater renal vasoconstrictor response to sympathetic activation.”
According to the researchers, their work adds to the body of evidence that “chronic excessive fructose intake” can play a role in elevating the risk for kidney disease. – by Melissa J. Webb
Disclosures: The authors report no relevant financial disclosures.