In brief
Hyperuricemia is not limited to gout: it's also a risk factor for calcium oxalate and urate kidney stones. Diet plays a direct preventive role, particularly by limiting animal proteins, alcohol, and salt while increasing hydration. Some high-oxalate foods (spinach, rhubarb, nuts) need monitoring in cases of oxalate stones. A practical overview of foods to watch.
When people think about uric acid, gout comes to mind first. But what is less well known is that hyperuricaemia also promotes the formation of certain kidney stones — in particular urate stones. Understanding this connection allows you to adapt your diet on two fronts at once.
What is the link between uric acid and kidney stones?
Uric acid is eliminated by the kidneys through urine. When blood levels are too high, it can crystallise in the urinary tract and form stones. Urate stones account for about 10% of all kidney stones. They are more common in people with gout or chronic hyperuricaemia.
Another important point: some foods that are good for limiting gout can, conversely, promote other types of stones (calcium oxalate, for example). This is why you should not think only in terms of purines.
Foods to prioritise watching
To reduce the risk of urate stones, the same recommendations apply as for gout: limit foods very high in purines such as offal, anchovies, sardines, mussels and certain red meats. These foods increase uric acid production and therefore its concentration in urine.
Fructose deserves particular attention: it increases endogenous uric acid production. Sugary sodas, industrial fruit juices and high-fructose corn syrup products should therefore be limited.
Also watch out for spinach, rhubarb and nuts if you have a history of oxalate stones — these foods can promote a different type of stone, even though they are neutral for gout.
What protects your kidneys
Hydration is the number one lever. Drinking enough water — at least 1.5 to 2 litres per day — dilutes urine and reduces the concentration of uric acid. Slightly alkaline waters can help maintain a favourable urinary pH.
Citrus fruits, particularly lemon, provide citrates that inhibit crystal formation. Low-fat milk and dairy products are also associated with a reduced risk of urate stones.
A nutritional assessment that goes beyond purines
This is precisely why our AUG Index Database includes a specific Kidney Stone index, which cross-references 16 parameters for each food: purines, oxalates, citrates, potassium, calcium, phosphorus, estimated urinary pH, and more. For each food, you get a score that takes all these interactions into account — not just purines.
This approach is particularly useful if you want to both reduce your uric acid and protect your kidneys — two goals that sometimes require different trade-offs depending on the food.
Want to go further?
Browse our database of 2,281 foods with the 3 AUG composite indices crossing up to 22 parameters (gout, stones, weight), or download our practical guide with 7-day meal plans.
