Public health recommendations generally suggest drinking eight cups of water a day. And many people just assume it’s healthy to drink plenty of water.
Now researchers at UC San Francisco have taken a systematic look at the available evidence, analysed 18 randomised controlled trials. In their review, published in JAMA Network Open, they concluded that drinking enough water can help with weight loss and prevent kidney stones, as well as migraines, urinary tract infections and low blood pressure.
“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,” said Benjamin Breyer, MD, MAS, professor and chair of the UCSF Department of Urology.
“The amount of rigorous research turned out to be limited, but in some specific areas, there was a statistically significant benefit,” said Breyer, the senior author of the study. “To our knowledge, this is the first study assessing the benefits of water consumption on clinical outcomes broadly.”
Strong evidence suggested that drinking eight cups of water a day significantly decreased the likelihood of getting another kidney stone. Several studies found that drinking about six cups of water a day helped adults lose weight. But a study that included adolescents found that drinking a little more than eight cups of water a day had no effect.
Still, the authors said that encouraging people todrink water before meals would be a simple and cheap intervention that could have huge benefits, given the increased prevalence of obesity.
Other studies indicated that water can help prevent migraines, control diabetes and low blood pressure, and prevent urinary tract infections. Adults with recurrent headaches felt better after three months of drinking more water. Drinking about four more cups of water a day helped diabetic patients whose blood glucose levels were elevated.
Drinking an additional six cups a day of water also helped women with recurrent urinary tract infections. It reduced the number of infections and increased the amount of time between them. Drinking more water also helped young adults with low blood pressure.
“We know that dehydration is detrimental, particularly in someone with a history of kidney stones or urinary infections,” Breyer said. “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.”
Health care providers in developing countries know that oral rehydration salts (ORS) are a lifesaving and inexpensive treatment for diarrhoeal disease, a leading cause of death for children worldwide – yet few prescribe it.
A new study published in Sciencesuggests that closing the knowledge gap between what treatments health care providers think patients want and what treatments patients really want could help save half a million lives a year and reduce unnecessary use of antibiotics.
“Even when children seek care from a health care provider for their diarrhoea, as most do, they often do not receive ORS, which costs only a few cents and has been recommended by the World Health Organization for decades,” said Neeraj Sood, senior author of the study, senior fellow at the USC Schaeffer Center for Health Policy & Economics and a professor at the USC Price School of Public Policy.
“This issue has puzzled experts for decades, and we wanted to get to the bottom of it,” said Sood.
A closer look at childhood illness in India
There are several popular explanations for the underprescription of ORS in India, which accounts for the most cases of child diarrhoea of any country in the world:
Physicians assume their patients do not want oral rehydration salts, which come in a small packet and dissolve in water, because they taste bad or they aren’t “real” medicine like antibiotics.
The salts are out of stock because they aren’t as profitable as other treatments.
Physicians make more money prescribing antibiotics, even though they are ineffective against viral diarrhea.
To test these three hypotheses, Sood and his colleagues enrolled over 2000 health care providers across 253 medium-size towns in the Indian states of Karnataka and Bihar. The researchers selected states with vastly different socioeconomic demographics and varied access to health care to ensure the results were representative of a broad population. Bihar is one of the poorest states in India with below-average ORS use, while Karnataka has above-average per capita income and above-average ORS use.
The researchers then hired staff who were trained to act as patients or caretakers. These “standardized patients” were given scripts to use in unannounced visits to doctors’ offices where they would present a case of viral diarrhea — for which antibiotics are not appropriate — in their 2-year-old child. (For ethical considerations, children did not attend these visits.) The standardized patients made approximately 2,000 visits in total.
Providers were randomly assigned to patient visits where patients expressed a preference for ORS, a preference for antibiotics or no treatment preference. During the visits, patients indicated their preference by showing the health care provider a photo of an ORS packet or antibiotics. The set of patients with no treatment preference simply asked the physician for a recommendation.
To control for profit-motivated prescribing, some of the standardized patients assigned as having no treatment preference informed the provider that they would purchase medicine elsewhere. Additionally, to estimate the effect of stockouts, the researchers randomly assigned all providers in half of the 253 towns to receive a six-week supply of ORS.
Provider misperceptions matter most when it comes to ORS underprescribing
Researchers found that provider perceptions of patient preferences are the biggest barrier to ORS prescribing – not because caretakers do not want ORS, but rather because providers assume most patients do not want the treatment. Health care providers’ perception that patients do not want ORS accounted for roughly 42% of underprescribing, while stockouts and financial incentives explained only 6% and 5%, respectively.
Patients expressing a preference for ORS increased prescribing of the treatment by 27 percentage points — a more effective intervention than eliminating stockouts (which increased ORS prescribing by 7 percentage points) or removing financial incentives (which only increased ORS prescribing at pharmacies).
“Despite decades of widespread knowledge that ORS is a lifesaving intervention that can save lives of children suffering from diarrhea, the rates of ORS use remain stubbornly low in many countries such as India,” said Manoj Mohanan, co-author of the study and professor of public policy, economics, and global health at the Sanford School of Public Policy at Duke University. “Changing provider behavior about ORS prescription remains a huge challenge.”
Study authors said these results can be used to design interventions that encourage patients and caretakers to express an ORS preference when seeking care, as well as efforts to raise awareness among providers about patients’ preferences.
“We need to find ways to change providers’ perceptions of patient preferences to increase ORS use and combat antibiotic resistance, which is a huge problem globally,” said Zachary Wagner, the study’s corresponding author, an economist at RAND Corporation and professor of policy analysis at Pardee RAND Graduate School. “How to reduce overprescribing of antibiotics and address antimicrobial resistance is a major global health question, and our study shows that changing provider perceptions of patient preferences is one way to work toward a solution.”
There is more risk of suffering concussions or being misdiagnosed with head trauma is greater among fighters who rapidly cut weight before bouts, usually by dehydrating, researchers have revealed for the first time.
More than 60% of athletes in combat sports such as boxing and mixed martial arts (MMA) reported that their symptoms worsened after they dehydrated to make strict weight classes.
These controversial weight cutting techniques involve stop drinking water and endure long periods in saunas.
MMA athletes reported concussion severity to be 40% higher compared to other sports, particularly boxing – believed to be due to the mix of striking and contact with the ground.
Published in the Clinical Journal of Sports Medicine, the study comes after a series of tragedies associated with weight cuts, with some athletes even dying in the attempt to achieve a perceived competitive edge, by competing in a smaller weight class.
They found that as competitors dramatically dehydrate themselves to meet stringent weight classes, the associated symptoms may ‘muddy the waters’ of baseline concussion testing, due to similar symptoms.
This is because the symptoms of hypohydration – where competitors enter a water deficit – match concussive signs, such as dizziness, headaches, and lethargy.
This study has spurred further probes into the neurological implications of rapid weight loss. The researchers have called on governing bodies to check fighters’ hydration levels before fights.
Researcher Nasir Uddin, from St Mary’s University, said: “This study shows that current concussion testing does not account for the crossover of symptoms from being dehydrated, and is potentially putting fighters at risk.
“Not only is cutting weight through dehydration in and of itself dangerous, but it might actually exacerbate concussion symptoms and, even more concerningly, means medical professionals may actually misdiagnose it.
“Going forward, governing bodies should ensure hydration and baseline concussion symptoms are taken into account before and after bouts.”
The study surveyed more than 130 anonymous athletes representing six combat sports, all aged 18 or above and who had previously cut weight.
It also found that 65% of the fighters had an experience of a weight cut “not going to plan”, suffering a lack of energy, strength, power, coordination or increased susceptibility to being ‘rocked’ during a bout.
This means the dangerous practice may not offer a competitive advantage after all.
Dr Jamie Tallent, from the University of Essex, said: “This is perhaps the most surprising finding that not only are weight cuts dangerous – they leave fighters at a disadvantage more often than not and may exacerbate the risks of being further injured.”