Sugary Drinks Cause Kidney Stones-and It's Worse Than Expected
- 01. Sugary Drinks and Kidney Stones: The Science Behind the Risk
- 02. How Strong Is the Evidence?
- 03. What Sugary Drinks Raise the Risk?
- 04. How Sugary Drinks Promote Kidney Stones
- 05. Comparing Risk Across Common Beverages
- 06. Who Is Most at Risk?
- 07. How Much Is "Too Much"?
- 08. What Should You Drink Instead?
Sugary Drinks and Kidney Stones: The Science Behind the Risk
Yes, regular consumption of sugary drinks is associated with a higher risk of developing kidney stones, according to multiple large epidemiological studies published in the past decade. While they do not "directly cause" stones in everyone, frequent intake of sugar-sweetened sodas, punches, and similar beverages measurably elevates the odds of kidney stone formation, especially in otherwise healthy middle-aged and young adults. This article unpacks the evidence, explains the biological mechanisms, and offers practical guidance for reducing risk.
How Strong Is the Evidence?
Several prospective cohort studies of tens of thousands of adults have now linked sugar-sweetened beverages to kidney stones. A landmark 2013 analysis of over 190,000 men and women in the U.S., led by Dr. Gary Curhan at Brigham and Women's Hospital, found that participants who drank one or more sugar-sweetened cola servings per day had a 23% higher risk of stones compared with those who consumed less than one serving per week. Similar risk elevations were seen for sugar-sweetened non-cola drinks such as fruit punches, with some subgroups facing up to a 33% higher risk at the highest intake levels.
A more recent 2025 study focusing on middle-aged and young U.S. adults, published in a peer-reviewed nephrology journal, reported that both absolute and relative intake of sugar-sweetened beverages were positively associated with kidney stones. After adjusting for body mass index, age, dietary calcium, and other confounders, the odds of stones increased across rising tertiles of daily SSB intake, with the highest tertile associated with roughly a 66% higher odds of kidney stones compared with non-consumers.
What Sugary Drinks Raise the Risk?
Not all sweetened beverages behave the same way, but several categories consistently show elevated risk in observational data. Among the most strongly implicated are:
- Sugar-sweetened colas (regular soda, not diet) linked to about a 20-23% higher risk in high-consumption groups.
- Sugar-sweetened non-cola drinks, including many fruit punches and sweetened teas, associated with up to a 33% higher risk.
- Fruit-flavored sodas and punches, which often combine high fructose corn syrup with phosphoric or citric acid, appear to drive both osmotic and acid-load effects that favor stone formation.
By contrast, beverages such as coffee, tea, beer, wine, and orange juice (in moderation) have been associated with lower or neutral risk in the same cohorts, suggesting that the chemical profile of the drink-not just "sugar" per se-is key.
How Sugary Drinks Promote Kidney Stones
Sugary drinks contribute to kidney stones through several overlapping physiological pathways. First, high sugar intake raises urinary calcium and lowers urinary citrate, two direct drivers of calcium-based stone formation. When the body processes large amounts of sucrose or fructose from beverages, it can increase calcium excretion in the urine while simultaneously reducing citrate, a natural inhibitor of crystal formation.
Second, frequent consumption of sugar-sweetened sodas and punches is associated with lower overall urine volume if they displace water. Concentrated urine allows calcium, oxalate, and uric acid to approach supersaturation levels, making crystallization more likely. Even modest reductions in daily fluid intake, when paired with high sugar loads, can push susceptible individuals over the threshold for stone formation.
Finally, chronic high intake of sugary beverages is linked to obesity, insulin resistance, and type 2 diabetes, all of which independently increase kidney stone risk. A 2024 urology-focused review noted that individuals whose total daily calories from added sugar exceeded 25% showed an 88% higher chance of developing stones compared with those with lower sugar intake.
Comparing Risk Across Common Beverages
The table below summarizes approximate risk shifts observed in large population studies; "baseline risk" is arbitrarily set at 1.0 for low or no intake of a given beverage. These numbers are illustrative but closely reflect relative hazard ratios and odds ratios reported in recent literature. Note that absolute risk for any individual remains low, but the proportional differences are clinically meaningful at the population level.
| Beverage type | Typical intake pattern | Approximate relative risk of kidney stones |
|---|---|---|
| Sugar-sweetened cola | ≥1 serving per day vs. <1 per week | 1.23 (23% higher risk) |
| Sugar-sweetened non-cola (e.g., punch) | High vs. low intake | 1.33 (33% higher risk) |
| Diet cola | High vs. low intake | Approximately 1.0-1.1 (neutral to small increase) |
| Caffeinated coffee | ≥1 cup per day vs. little/no intake | 0.84 (16% lower risk) |
| Orange juice | Moderate vs. low intake | About 0.9 (slightly lower risk) |
This pattern underscores that the problem is not simply "sweetness" but the specific combination of sugar load, fluid displacement, and acid-base effects in sugar-sweetened beverages.
Who Is Most at Risk?
While sugary drinks can raise stone risk in many adults, certain groups appear more vulnerable. People with a prior history of kidney stones, a family history of stones, or conditions such as obesity and metabolic syndrome are disproportionately affected by high SSB intake. Men and women in their 30s-50s, who often consume the largest volumes of sugar-sweetened sodas, show the strongest associations in cohort data.
Young adults and adolescents are also a growing concern; a 2025 analysis of middle-aged and young adults found that higher relative sugar-sweetened beverage intake correlated with a 1.5- to 1.6-fold higher odds of kidney stones in the highest consumption tertiles after controlling for age, sex, and BMI. This suggests that the cumulative effect of years of daily soda or punch consumption may begin to manifest in early stone episodes by the mid-30s.
How Much Is "Too Much"?
Exact thresholds vary by individual, but observational data suggest that even modest daily intake of sugar-sweetened beverages can measurably increase risk. For example, drinking just one sugar-sweetened cola per day is associated with a 23% higher risk compared with having one or fewer per week. If someone instead consumes two or more servings per day, the incremental risk climbs further, as reflected in the dose-response curves in the 2025 analysis.
A practical guideline emerging from nephrology and urology reviews is to limit sugar-sweetened beverages to no more than one 12-ounce serving per day, and ideally to a few servings per week or less, especially for those with risk factors. For primary prevention, many clinicians recommend treating regular soda and punch as occasional treats rather than daily hydration sources.
What Should You Drink Instead?
For people concerned about kidney stone formation, evidence-based substitutions for sugary drinks include: water, lemon- or lime-infused water, citrus-rich beverages such as orange or grapefruit juice in moderation, and caffeinated coffee or tea. These options tend to increase urine volume and citrate or have neutral or protective effects on overall stone risk.
A stepwise plan for reducing risk might look like this:
- Track current daily intake of sugar-sweetened beverages over a week, noting types and portion sizes.
- Replace one daily soda or punch with water or an unsweetened tea, gradually reducing servings over 4-6 weeks.
- Aim for at least 2-2.5 liters of total fluid per day, with water as the primary source.
- Monitor for risk factors such as recurrent stones, obesity, or diabetes and discuss a personalized fluid and diet plan with a clinician.
In practical terms, the notion that "sugary drinks cause kidney stones" is not a myth, but it should be framed as an elevated risk rather than a guaranteed outcome. By swapping sugar-sweetened beverages for water and other lower-risk drinks, many adults can meaningfully reduce their chances of developing painful kidney stones without eliminating sweetness from their diets entirely.
Everything you need to know about Sugary Drinks Cause Kidney Stones And Its Worse Than Expected
Are diet sodas safer for kidney health?
Current evidence suggests that diet sodas are generally neutral or only slightly elevated in terms of kidney stone risk compared with regular sugar-sweetened options. Large cohort analyses have found that artificially sweetened colas show essentially no increased risk, while some artificially sweetened non-cola drinks may carry a small but statistically marginal elevation; none approach the 23-33% increases seen with sugar-sweetened colas and punches.
Can cutting out sugary drinks reverse existing stone risk?
Observational data indicate that lowering sugar-sweetened beverage intake is associated with a reduced incidence of new kidney stones over time, especially when combined with increased water intake and weight management. While existing mineral deposits in the kidneys may not fully "dissolve," reducing the biochemical drivers (high urinary calcium, low citrate, low urine volume) can substantially slow new stone formation and decrease recurrence rates.
Do sports drinks or fruit juices count as sugary drinks?
Many commercial sports drinks and fruit juices contain added sugars or high natural sugar content, so they should be treated similarly to soda in terms of kidney stone risk if consumed in large volumes. However, moderate portions of fresh citrus juice such as orange juice have been associated with slightly lower risk in some studies, likely due to their citrate content; this benefit disappears when intake becomes excessive or when juices displace water.
Is there a safe amount of sugar for people prone to kidney stones?
For individuals with a history of kidney stones, most urology and nephrology guidelines recommend keeping total added sugar to less than 10% of daily calories, and ideally under 5%. This roughly translates to under 50 grams of added sugar per day for a 2,000-calorie diet, with most of that allowance coming from whole foods rather than sugar-sweetened beverages.
How quickly does risk go down after stopping sugary drinks?
There is no definitive "timeline," but metabolic and urinary changes can begin within weeks of reducing sugar-sweetened beverage intake. Urinary calcium and pH may normalize, and stone-forming risk factors may decline over several months, especially when coupled with higher fluid intake and weight loss if needed.