Soft drink consumption and urinary stone recurrence: a randomized prevention trial.

Area of Science:

• Nephrology
• Urology
• Preventive Medicine

Background:

• A prior case-control study suggested a link between soft drink consumption and urinary stone recurrence in adult males.
• The causal relationship between soft drink intake and urinary stone disease recurrence requires further investigation.

Purpose of the Study:

• To determine if reducing soft drink consumption causally impacts the recurrence of urinary stone disease in adult males.
• To investigate the role of specific drink acidifiers (phosphoric vs. citric acid) in this association.

Main Methods:

• A randomized controlled trial involving 1009 adult males (aged 18-75) with a history of urinary stone disease and daily soft drink consumption (≥160 ml).
• Participants were randomized to either refrain from soft drinks or serve as controls.
• Follow-up was conducted over 3 years to assess recurrence-free rates.

Main Results:

• The intervention group (refraining from soft drinks) showed a 6.4% advantage in 3-year freedom from recurrence compared to the control group (p = 0.023).
• An interaction was observed based on drink acidification: subjects whose primary drink was acidified by phosphoric acid (not citric acid) had a 15% higher 3-year recurrence-free rate in the intervention group (p = 0.002).
• No significant difference in recurrence-free rates was observed for those whose primary drink was acidified by citric acid (p = 0.55), with the interaction being significant (p = 0.019).

Conclusions:

• Reducing soft drink consumption can be a causal factor in preventing urinary stone disease recurrence in adult males.
• The type of acidifier in consumed beverages plays a significant role, with phosphoric acid-based drinks showing a stronger association with recurrence prevention upon cessation.