For years the assumption about fructose was tidy: the sugar does its damage only after the liver breaks it down, and the trouble comes from the by-products of that breakdown. A study published on August 17, 2026 in Signal Transduction and Targeted Therapy (a Nature journal) tears that assumption down.
The team built a fructose probe and screened 72 candidate binding proteins before landing on TOM22. Cryo-electron microscopy showed the binding disrupts a conserved contact point and triggers a subtle shape change that is functionally significant. In mice fed a high-fructose diet for 12 weeks, mutating the binding site reversed the kidney injury: glomerular expansion eased, podocyte structure recovered, and urine albumin levels returned to normal.
Fructose has a second, better-known route into stone disease that runs through uric acid. When the liver processes fructose, it burns ATP and produces uric acid as a by-product, while simultaneously slowing the kidneys' uric acid clearance. The result is a higher uric acid load in the urine — the raw material for uric acid stones, and a promoter of calcium oxalate stones as well. This new study adds a layer on top: fructose can also injure the kidney's filtering cells directly, independent of that uric acid pathway.
High-fructose corn syrup sits in soft drinks, baked goods, and processed condiments across the American food supply. The concern is not the fructose in a piece of fruit, which arrives with fiber and water. It is the added, concentrated fructose that outpaces what the body evolved to handle.
Oxalate is only one lens on a drink. Here is how common sweet and sparkling drinks compare on lab-measured oxalate:
| Food | Oxalate (mg) | Serving | Rating |
|---|---|---|---|
| Soda, regular or diet | 1 mg | 12 oz | Safe |
| Lemonade | 2 mg | 1 cup | Safe |
| Sports drink (Gatorade) | 0 mg | 12 fl oz | Safe |
| Sparkling water, unsweetened | 0 mg | 12 fl oz | Safe |
| Orange, fresh | 14 mg | 1 medium | Safe |
The oxalate numbers are low across the board — the risk in the drink column is rarely the oxalate. It is the added fructose and the fact that a sweet drink displaces the plain water that would otherwise keep urine dilute.
None of this means you have to give up fruit. Whole fruit carries fiber, water, and a modest fructose load. The practical line is about added sugars, not natural ones. If you are stone-prone, the highest-value swaps are in the drink column: move the daily soda or sweet tea to the occasional slot, keep the water bottle in reach, and read labels for high-fructose corn syrup in foods you would not expect it in, such as breads and condiments.
See how oxalate values are measured and verified on our data methodology page.