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Sugary Drinks and Kidney Stones: The UK Biobank Numbers, and What to Drink Instead

2026-08-16 · By Sarah Chen, Data Editor · Dietary reference, not medical advice
Why this matters now: Sugary drinks are back in the news this week on the strength of two large data sets: a UK Biobank analysis of 191,863 participants followed for 13.5 years, and a US NHANES analysis of 15,779 adults. Both found that higher sugar-sweetened beverage intake is linked to higher kidney stone risk — the UK data with a 51 percent higher risk at more than two drinks a day. For stone patients, the drink column is one of the easiest places to make a measurable change.

The UK Biobank Numbers

Researchers analyzed 191,863 UK Biobank participants who were free of kidney stones at the start. Beverage intake was measured with web-based 24-hour dietary recalls, and participants were grouped by sugar-sweetened beverage (SSB), artificially sweetened beverage (ASB), and natural juice consumption. Over a mean follow-up of 13.5 years, 2,024 new kidney stone cases occurred.

Compared with non-consumers, people who drank more than two units of sugar-sweetened beverages a day — where one unit is 250 ml, so roughly two 12-ounce cans — had a 51 percent higher risk of incident kidney stones (hazard ratio 1.51, 95% CI 1.17-1.95), with a significant dose-response trend. Artificially sweetened beverages showed a non-linear association, and natural juices showed no significant association. Genetic susceptibility predicted risk independently but did not substantially change the beverage relationship — in other words, the drink effect did not disappear in people with lower genetic risk scores.

The US Data Agree

The US picture comes from NHANES 2007-2016, analyzed in a 2025 World Journal of Urology paper: 15,779 middle-aged and young adults, of whom 1,224 had kidney stones. Both absolute SSB intake (per 100 kcal per day) and relative intake (SSB as a percent of daily energy) were positively associated with stone risk. Compared with non-consumers, the highest tertile of absolute SSB intake carried a 66 percent higher odds (OR 1.664, 95% CI 1.353-2.048), and the association was stable across most stratified analyses.

Two limits belong in any honest reading. Both are observational, so they show association rather than proof of cause and effect. And the mechanism they point to — sugary drinks raise urinary calcium and uric acid excretion, shift urine pH, and can displace water — is well supported but not fully proven in a single study. The practical message that survives across both data sets: regular sugary drinks are one of the more consistent diet-to-stone links in the literature, and cutting them is a low-cost, low-risk change.

What to Drink Instead

The drink swap is simple because the oxalate column is short and mostly favorable. Water is the base of the plan. Milk adds calcium and fluid in one glass — a two-for-one on the stone table. Citrus drinks like lemonade add citrate, which helps inhibit crystal formation. And the natural juices that the UK Biobank analysis found unassociated with stone risk — orange, apple, cranberry — measure low oxalate, though they still carry sugar and calories and are best kept to a glass.

The swap that matters most is the daily one: replace the regular soda or sweet tea with water, milk, or a low-sugar citrus drink. The UK Biobank data suggest the difference shows up in the two-drinks-a-day range, which is exactly where habitual intake tends to sit.

The Drink Table, Measured

The table below shows the measured oxalate values of the common drink choices.

FoodOxalate (mg)ServingRating
Water01 cupSafe
Milk, whole or low-fat01 cupSafe
Lemonade, fresh21 cupSafe
Orange juice, fresh11 cupSafe
Apple juice, unsweetened11 cupSafe
Cranberry juice31 cupSafe
Soda, cola-type112 ozSafe
Soda, diet112 ozSafe
Black tea10-151 cupSafe
Green tea3-51 cupSafe

The Habit, Measured

The UK Biobank threshold — more than two sugary drinks a day — is the practical line. The person at two-plus cans a day is the one the data most clearly flag, and the swap to water or milk at one of those slots is the highest-value change available in the drink column. The measured version of the habit is a bottle of water where the second can used to be, and the citrus or milk where the first one is.

The Family Drink Drawer

Because the drink habit is set at the household level, the highest-value version of this change is the family drink drawer: the water bottles and the milk live where the soda used to live, the sugary drinks move to the occasional shelf, and the juice is portioned to a glass. For families with a stone history — especially one that includes a teenager, whose intake is the most habit-driven — the drawer does the reminding that individual resolutions rarely sustain. The UK Biobank data suggest the effect is dose-dependent: the risk climbs with each additional sugary drink, so every can moved out of the daily rotation moves the family's baseline in the measured direction, even if the occasional treat stays.

Frequently Asked Questions

Do diet sodas cause kidney stones?

The UK Biobank analysis found a non-linear association for artificially sweetened beverages — not the clear dose-response seen with sugar-sweetened drinks. The safest read: diet sodas are not the first thing to cut, but water is still the better base for the plan.

Is fruit juice safe with kidney stones?

Most natural juices measure low oxalate, and the UK Biobank analysis found no significant association between natural juice intake and incident stone risk. Keep it to a glass, since juice still carries sugar and calories, and prefer whole fruit for the fiber.

How much water should replace the soda?

The working target is a urine output of about 2.5 liters a day, which for most adults means roughly 3 liters of total fluid. Swapping even one daily sugary drink for water or milk moves the plan in the right direction.

Sources:
Harvard T.H. Chan School of Public Health Oxalate Database (2024); USDA FoodData Central; eBioTrade: "Sweetened beverage intake and risk of incident kidney stone: UK Biobank" (Frontiers in Nutrition); Peng et al., World Journal of Urology 2025 (NHANES 2007-2016, n=15,779) All oxalate values are lab-measured via ion chromatography. This page is a dietary reference tool, not medical advice.

See how oxalate values are measured and verified on our data methodology page.

Medical Disclaimer: This site is a dietary reference tool based on published food composition data. It does not provide medical advice, diagnose, or treat any condition. Talk to your doctor or a registered dietitian before changing your diet, especially if you have kidney stones, kidney disease, or other medical conditions.