A recent study has suggested that kidney stones, which affect thousands of people around the world could be triggered by added sugars in the diet.
Common symptoms are severe pain, nausea, vomiting, fever, chills and bloody urine, but, said the researchers, kidney stones don’t just reduce the quality of life; in the long run, they may lead to infections, swollen kidneys (hydronephrosis), renal insufficiency, and end-stage renal disease.
The scientists said that known risk factors include being an adult male, obesity, chronic diarrhoea, dehydration, and having inflammatory bowel disease, diabetes, or gout, and now, as their study has shown for the first time, an elevated consumption of added sugars should probably be added to the list of risk factors.
MedicalXPress reports that added sugars occur in many processed foods, but are especially abundant in sugar-sweetened sodas, fruit drinks, sweets, ice cream, cakes and biscuits.
The findings were published in Frontiers in Nutrition.
“Ours is the first study to report an association between added sugar consumption and kidney stones,” said lead author Dr Shan Yin, a researcher at the Affiliated Hospital of North Sichuan Medical College, Nanchong, China. “It suggests that limiting added sugar intake may help to prevent the formation of kidney stones.”
Yin and the team analysed epidemiological data on 28 303 men and women, collected between 2007 and 2018 within the US National Health and Nutrition Examination Survey (NHANES).
Participants self-reported if they had a history of kidney stones.
Each person’s daily intake of added sugars was estimated from their recall of their most recent consumption of food and drinks, given twice: once in a face-to-face interview, and once in a telephone interview between three and 10 days later. For example, they were asked if they had eaten syrups, honey, dextrose, fructose, or pure sugar during the past 24 hours.
Each person also received a healthy eating index score (HEI-2015), which summarised their diet in terms of the adequacy of beneficial diet components such as fruits, vegetables, and whole grains, and moderation of potentially harmful foods, for example, refined grains, sodium and saturated fats.
The researchers adjusted the odds of developing kidney stones per year during the trial for a range of explanatory factors. These included gender, age, race or ethnicity, relative income, BMI, HEI-2015 score, smoking status, and whether the participants had a history of diabetes.
At the start of the study, participants with a higher intake of added sugar tended to have a higher current prevalence of kidney stones, a lower HEI score, and a lower education level. The overall mean intake of added sugars was 272.1 calories per day, which corresponds to 13.2% of the total daily energy intake.
Positive link between sugars and stones
The researchers showed that after adjusting for these factors, the percentage of energy intake from added sugars was positively and consistently correlated with kidney stones. For example, participants whose intake of added sugars was among the 25% highest in the population had 39% greater odds of developing kidney stones over the course of the study.
Similarly, those who derived more than 25% of their total energy from added sugars had a 88% greater odds than those who derived less than 5% of their total energy from added sugars.
The results also indicated that participants from “other” ethnicities – for example, Native American or Asian people – had higher odds of developing kidney stones when exposed to greater-than-average amounts of added sugars than Mexican American, other Hispanic, non-Hispanic white, and non-Hispanic black people.
People with a greater poverty-income ratio (PIR; i.e, the ratio between their income and the federal poverty level) had greater odds of developing kidney stones when exposed to more added sugars than people at or slightly above poverty level.
Possibility of confounders
The mechanisms of the relation between consuming more added sugars and a greater risk of developing kidney stones is not yet known.
Because this was an uncontrolled observational trial, it can’t yet be ruled out that unknown confounding factors might drive this association.
“Further studies are needed to explore the association between added sugar and various diseases or pathological conditions in detail,” cautioned Yin.
“For example, what types of kidney stones are most associated with added sugar intake? How much should we reduce our consumption of added sugars to lower the risk of kidney stone formation? Nevertheless, our findings already offer valuable insights for decision-makers.”
Study details
Association between added sugars and kidney stones in US adults: data from National Health and Nutrition Examination Survey 2007-2018.
Published in Frontiers in Nutrition on 4 August 2023.
Shan Yin, Zhenzhen Yang, Pingyu Zhu, Zhongbo Du, Xiaodong Yu, Tielong Tang, Yan Borné.
Purpose
Added sugar is associated with a variety of adverse health outcomes, but its association with kidney stones is unclear. This study was to determine whether added sugar is associated with kidney stones.
Materials and methods
This nationally representative study used National Health and Nutrition Examination Survey (NHANES) datasets from 2007 to 2018 for analysis. People aged ≥20 years who reported a history of kidney stones and provided dietary recall data on added sugars were included. Weighted proportions, multivariable logistic regression analysis and stratified logistic regression were used to evaluate the associations between added sugars and kidney stones by adjusting potential confounders.
Results
Totally 28,303 adults were included, with weighted mean age [95% confidence interval (CI)] of 48.03 (47.56, 48.51) years, 47.74% (47.09, 48.40%) males and 52.26% (51.60, 52.91%) females. The overall mean (95% CI) energy intake from added sugars was 272.10 (266.59, 277.60) kilocalories. In the fully-adjusted multivariable model, the percentage of energy intake from added sugars was positively correlated with kidney stones. Compared to the first quartile of added sugar energy intake percentage, the population in the fourth quartile had a higher prevalence of kidney stones (OR = 1.39; 95% CI 1.17 to 1.65). Compared with the less than 5% calories from added sugar population, the more than or equal to 25% calories from added sugar had a higher kidney stone prevalence (OR = 1.88; 95% CI 1.52 to 2.32).
Conclusion
A higher percentage of energy intake from added sugars is significantly associated with a higher prevalence of kidney stones. This study provides cross-sectional evidence for the relationship between added sugars and health outcomes.
MedicalXPress article – Consuming added sugars may increase risk of kidney stones (Open access)
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