A study published in 2026 tested whether tart cherry and purple sweet potato extracts, taken together, could lower uric acid in rats fed a high-purine diet. The results were promising — the best dose combination brought uric acid down to a level statistically similar to the drug allopurinol. That sounds like a headline, but it is an animal study, and the gap between a rat on a yeast diet and a person with gout is wide. Here is what the study actually found and how much weight it should carry.
Researchers at Shandong First Medical University induced hyperuricemia in young male rats using a standard laboratory method: a diet containing 2% potassium oxonate plus 20% yeast, which blocks uric acid breakdown and floods the system with purines. After five weeks, they split the rats into six groups. One group received allopurinol, one was switched back to a normal diet, and three groups received different combinations of tart cherry extract and purple sweet potato extract, given for two weeks.
The three combination doses were 300 mg/kg cherry plus 300 mg/kg purple sweet potato, 500 mg/kg cherry plus 300 mg/kg purple sweet potato, and 300 mg/kg cherry plus 500 mg/kg purple sweet potato. All three reduced uric acid, but the third combination — the one highest in purple sweet potato — performed best.
In the best-performing group, uric acid fell from about 165.8 μmol/L before intervention to about 71.0 μmol/L after. For comparison, the allopurinol group and the normal-diet group also dropped significantly, and the authors reported no statistically significant difference between the best cherry-plus-purple-sweet-potato group and either the allopurinol group or the normal-diet group. In other words, the plant extract combination performed about as well as switching off the high-purine diet entirely — in rats.
Those numbers are specific to this rodent model and cannot be read as a dose for humans. A rat dose of 300 mg/kg does not translate to "eat this many cherries a day." The study is a signal that the combination has a real, measurable urate-lowering effect in a controlled model, not a prescription.
The mechanism is not fully worked out, but both foods are rich in anthocyanins, the pigments that give cherries their red color and purple sweet potatoes their deep violet flesh. Anthocyanins have been studied for their antioxidant and anti-inflammatory effects, and in the context of gout, cherries specifically have a body of human evidence behind them. A well-known 2012 case-crossover study found cherry intake over a two-day period was associated with about a 35% lower risk of gout attacks, and cherry extract has been linked to lower serum urate in some smaller trials.
Purple sweet potato is a less-studied angle. Its anthocyanin content is high, and some cell and animal work suggests it can reduce oxidative stress and influence uric acid handling, but the human data is essentially absent. The 2026 rat study adds a preliminary data point to a mechanism that is biologically plausible but nowhere near established in people.
The practical takeaway is modest. Cherries already sit on the short list of foods with real — if imperfect — evidence for reducing gout flares, and they are low in purines and low in fructose as whole fruit. Adding whole cherries to a gout-friendly diet is a low-risk choice that aligns with the existing human research. Purple sweet potato is also low in purines and a reasonable, nutrient-dense carbohydrate, but its urate-lowering effect in humans is unproven, and it should be treated as a healthy food rather than a treatment.
Neither food is a substitute for urate-lowering medication when that is medically indicated, and neither is a license to ignore the fundamentals — limiting alcohol, red meat, and sugary drinks, and staying hydrated. The rat study is an encouraging hint, not a reason to change treatment.
There is one more gap worth naming between the study and the kitchen: the rats received concentrated extracts, not whole cherries and whole sweet potatoes. Extracts isolate and dose the active compounds — anthocyanins in this case — at levels that would be impractical to match by eating whole food. A person would have to consume an implausible volume of cherries or purple sweet potato to approach the extract doses used in the lab. This is a standard limitation of plant-compound research and another reason to treat the finding as a mechanism signal rather than a dietary instruction.
That said, the whole-food versions remain sensible choices for gout regardless of this study. Whole cherries are low in purines, low in fructose relative to dried fruit and juice, and backed by their own human evidence on flare reduction. Purple sweet potato is a fiber-rich, low-purine carbohydrate. Eating them as foods is reasonable; expecting them to act like the concentrated extracts in this study is not.
Medical Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition.