Increased coffee and caffeine consumption tied to lower risk of kidney stones: Study

Sweden: Coffee and caffeine intake may prevent kidney stone disease, according to results from a Mendelian randomization study based on genetic data from 2 large studies. This study was conducted by Shuai Yuan and Susanna C. Larsson from Sweden, the findings of whose work were published in the American Journal of Kidney Diseases on 21st October 2021.

In observational studies, coffee and caffeine consumption were linked to a decreased incidence of kidney stones. As a result, this study used Mendelian randomization to determine the causative nature of these correlations.

For this study independent genetic variants related to coffee and caffeine consumption at the genome-wide significance level were chosen as instrumental variables for this investigation from previously published meta-analyses. The UK Biobank project (6,536 cases and 388,508 noncases) and the FinnGen collaboration provided summary-level data for kidney stones (3,856 cases and 172,757 noncases). Participants were subjected to coffee and caffeine intake that was genetically predicted. The existence of Kidney stones affected the final result. To obtain causal estimates, Mendelian randomization methods were utilized. The fixed-effects meta-analysis methods were used to integrate the estimates from the two sources.

The key findings of this work were as follows:

1. In a combined sample of 7,396 cases and 530,411 noncases, the current MR investigation found inverse relationships of genetically predicted coffee and caffeine consumption with risk of kidney stones, which confirmed findings from most but not all observational studies.

2. In the UK Biobank study genetically predicted coffee and caffeine consumption was related to a decreased incidence of kidney stones, and the relationships were directionally identical in the FinnGen collaboration.

3. The combined odds ratio for kidney stones was 0.60 for a genetically predicted 50% increase in coffee intake and 0.81 for an 80-mg increase in caffeine consumption.

In conclusion, this MR investigation presents genetic evidence in favor of causal inverse correlations between coffee and caffeine consumption and renal stones. Increasing coffee and caffeine consumption may be a kidney stone preventive approach.

Reference:

Yuan, S., & Larsson, S. C. (2022). Coffee and Caffeine Consumption and Risk of Kidney Stones: A Mendelian Randomization Study. In American Journal of Kidney Diseases (Vol. 79, Issue 1, pp. 9-14.e1). Elsevier BV. https://doi.org/10.1053/j.ajkd.2021.04.018