Effects of dietary glucose and fructose on copper, iron, and zinc metabolism parameters in humans

Authors: HARDER, NATHANIEL - University Of California, Davis; HIERONIMUS, BETTINA - University Of California, Davis; STANHOPE, KIMBER - University Of California, Davis; SHIBATA, NOREENE - University Of California, Davis; LEE, VIVIEN - University Of California, Davis; NUNEZ, MARINELLE - University Of California, Davis; Keim, Nancy; BREMER, ANDREW - National Institutes Of Health (NIH); HAVEL, PETER - University Of California, Davis; HEFFERN, MARIE - University Of California, Davis; MEDICI, VALENTINA - University Of California, Davis

Submitted to: Nutrients
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/21/2020
Publication Date: 8/25/2020
Citation: Harder, N.H., Hieronimus, B., Stanhope, K.L., Shibata, N.M., Lee, V., Nunez, M.V., Keim, N.L., Bremer, A., Havel, P.J., Heffern, M.C., Medici, V. 2020. Effects of dietary glucose and fructose on copper, iron, and zinc metabolism parameters in humans. Nutrients. 12(9):2581. https://doi.org/10.3390/nu12092581.
DOI: https://doi.org/10.3390/nu12092581

Interpretive Summary: The metals copper, iron, and zinc are essential in human nutrition, but little is known how the inclusion of sweetened beverages in the diet affect these nutrients and their respective roles in human health, despite some indications from animal studies that this might be the case. We studied healthy young adults and measured these metals and important biomarkers of their activity before and after they added large amounts of sweetened beverages to their usual diets for 2 weeks. We found that beverages sweetened with the sugars fructose and glucose decreased copper and zinc in blood and also the activity of a copper containing enzyme. Further, the changes in biomarkers of these minerals were associated with increases in some risk factors of cardiovascular disease or control of blood glucose. These findings are the first evidence that consumption of sugar-sweetened beverages can alter clinical parameters of these micronutrients in healthy subjects.

Technical Abstract: Alterations of transition metal levels have been associated with obesity in humans. Studies in animal models indicate an association between dietary sugars and copper metabolism. Previous studies from our group demonstrated that a 2-week intervention with high fructose corn syrup-sweetened beverages increased cardiovascular risk factors in young adults. In serum samples from 107 healthy subjects, we measured parameters of copper metabolism including copper levels, ceruloplasmin ferroxidase activity, and ceruloplasmin protein levels in addition to zinc levels and iron metabolism parameters at baseline and after a 2-week intervention period where subjects consumed beverages sweetened with glucose, fructose, high fructose corn syrup or aspartame. Fructose and/or glucose consumption were associated with decreased ceruloplasmin ferroxidase activity and copper and zinc concentrations. Ceruloplasmin protein levels did not change in response to intervention. The changes in copper were correlated to zinc, but not to iron. The decreases in copper, ceruloplasmin ferroxidase activity, ferritin and transferrin were inversely associated with the increases in metabolic risk factors associated with sugar consumption, specifically, apolipoprotein CIII, triglycerides, or post-meal glucose, insulin, and lactate responses. These findings are the first evidence that consumption of sugar-sweetened beverages can alter clinical parameters of transition metal metabolism in healthy subjects.