‘Simple and ubiquitous’: Increasing water intake may help several health conditions

Key takeaways:

• Additional water intake may help migraines, kidney stones, fasting blood glucose, UTIs and overweight and obesity.
• However, there is not a one-size-fits-all approach to water consumption, a researcher said.

Increased water consumption has been linked to beneficial health outcomes like weight loss and fewer kidney stones, a systematic review published in JAMA Network Open showed.

Findings also revealed a limited number of studies showing associations between water consumption and prevention of migraines and UTIs, researchers noted.

According to the Mayo Clinic, the U.S. National Academies of Sciences, Engineering and Medicine recommends a daily water intake of about 15.5 cups for men and 11.5 cups for women.

“For such a ubiquitous and simple intervention, the evidence hasn’t been clear and the benefits were not well-established, so we wanted to take a closer look,” Benjamin Breyer, MD, MAS, study co-author and the Taube Family Distinguished Professor at the University of California San Francisco, said in a press release. “To our knowledge, this is the first study assessing the benefits of water consumption on clinical outcomes broadly.”

The researchers searched multiple databases for studies that assessed the effects of additional water intake on a variety of health outcomes.

They found a total of 18 randomized controlled trials (RCTs) published between 1999 and 2023 included in the analysis. Among them, 15 were parallel group RCTs and three were cross-over studies, while sample sizes ranged from 14 to 631 participants.

The researchers noted that the intervention periods in the included studies ranged from 4 days to 5 years, while the control groups were usually asked to maintain their usual water intake.

Breyer and colleagues found that in three parallel RCTs, adults with overweight or obesity who consumed 1,500 mL of water daily before meals over periods of 12 weeks to 12 months had greater weight loss of 44% to 100% compared with the control groups.

Meanwhile, in two studies, study investigators reported15 fewer nephrolithiasis events per 100 participants over 5 years among people who consumed 2,000 mL additional water daily vs. their control counterparts.

In one RCT composed of 140 postmenopausal women with recurring UTIs, an increased water intake of 1,500 mL daily corresponded with a lower mean number of UTI episodes (1.5 episodes; 95% CI, 1.2-1.8) over a 12-month period.

“We know that dehydration is detrimental, particularly in someone with a history of kidney stones or urinary infections,” Breyer said in the release. “On the other hand, someone who suffers from frequent urination at times may benefit from drinking less. There isn’t a one size fits all approach for water consumption.”

In another study, participants with recurrent headaches who increased their water intake by 1,500 mL daily for 3 months had fewer days with at least moderate headache (0.17 days; 95% CI, 1.3 to 1.6) vs. control participants, whereas more intervention participants reported much improvement.

However, these findings did not reach statistical significance.

Increased water intake further helped diabetes control. Specifically, in one RCT where intervention participants with recently diagnosed type 2 diabetes drank 250 mL of water before breakfast, 500 mL of water before lunch and 250 mL of water before dinner over the course of 8 weeks, there was a significant between-group difference in mean change in fasting blood glucose in the intervention group (32.6 mg/dL) vs. the control group (5.3 mg/dL).

Breyer and colleagues concluded that further studies should assess the benefits of additional water consumption on specific conditions like migraines and UTIs “given the obvious low cost and low adverse-effect profile of water.”

References:

• Drinking plenty of water may actually be good for you. Available at: https://www.ucsf.edu/news/2024/11/428961/drinking-plenty-water-benefits . Published Nov. 26, 2024. Accessed Dec. 16, 2024.
• Hakam N, et al. JAMA Netw Open. 2024;doi:10.1001/jamanetworkopen.2024.47621.
• Nutrition and healthy eating. Available at: https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/basics/nutrition-basics/hlv-20049477. Accessed Dec. 16, 2024.