When the temperature rises and people are active outside, they often reach for a refreshing drink to cool them down. But unless that drink is water, people could be putting their health at risk. A new study from the University of Buffalo found that drinking sugary and caffeinated soft drinks while being active in hot weather may increase the risk of developing kidney disease.
The study, which was published in the American Journal of Physiology — Regulatory, Integrative and Comparative Physiology, looked at healthy adults in a laboratory environment which was set to 95 degrees Fahrenheit. This setting is similar to that of working on an agricultural site on a hot day.
And according to Christopher Chapman, the study’s lead author and a Ph.D. candidate in exercise and nutrition sciences in the School of Public Health and Health Professions, “Our data suggest that consuming a high-fructose, caffeinated soft drink increases the blood pressure response to exercise in the heat. Additionally, these beverages elicit a mild dehydration and acutely elevate biomarkers of acute kidney injury compared to water consumption during and following exercise in the heat.”
Recent data suggest that there has been a rise in chronic kidney disease cases in the United States, many of which are found in farm workers in areas where the temperature is consistently hot. Many workers in the construction and agricultural industries spend long days outside in the heat. And while falls remain the number one cause of death in the construction industry, kidney disease is a rising concern.
Study participants were asked to complete an hour-long exercise routine, which was made up of running on the treadmill for 30 minutes, followed by lifting and sledgehammer swinging activities. After 45 minutes of exercise, the participants were asked to rest for 15 minutes — half of the participants then drank 16 ounces of Mountain Dew and the other half drank 16 ounces of water. They then repeated the exercise-and-hydration cycle three times.
After the four hours of exercising, the researchers took the participants’ body temperature, blood pressure, heart rate, body weight, and looked for signs of kidney injury. This information was gathered right after the four hours and 24 hours later. It’s also important to note that all of the participants did both a water trial and a soft drink trial, with a week in between the trials.
Results from the tests showed that after the soft drink trial, there were higher levels of creatinine in the participants’ blood and a lower glomerular filtration rate. These are both key indicators of kidney injury. Participants also showed signs of mild dehydration after the soft drink trial.
So with each American using 88 gallons of water every day at home, it’s important to get plenty of water throughout the day even at work — especially if you work in high temperatures. This study shows that it’s crucial for those manual laborers who work all day in the heat to choose water as their drink of choice whenever possible.