Your body is comprised of roughly 60 percent water, which has many essential tasks, including cushioning your joints and organs, transporting essential nutrients, maintaining internal temperature and electrolyte balance, and eliminating waste.
During hot days, water is even more important. Your body can withstand intense heat conditions, as well as vigorous activity, because water can effectively cool down your system through sweating. Given such an essential role, your daily beverage choices have a major impact on health.
Healthy beverage choices
Supermarket shelves are filled with dozens of beverage choices, from vitamin waters and sports drinks to juices, teas, wine and soda.
Here's our best advice on which beverages best quench your body's thirst:
1. Water. Turn to this inexpensive, calorie-free drink most of the time. Skip water bottles, however, which contribute to both greenhouse gas emissions and bulging landfills. Instead, rely on a home water infiltration system to create the best water straight from your tap.
2. Sports drinks. Rather than reaching for a post workout sports drink enhanced with electrolytes and sugar, you're probably best off with plain water. "For most people who exercise casually and have a good diet, this type of fluid replacement is not needed, as all electrolytes will be replaced via meals," says hydration expert, Robert W. Kenefick, Ph.D., Research Physiologist with the Thermal and Mountain Medicine Division for the U.S. Army Research Institute of Environmental Medicine. However, for those working daily in heat or engaging in intense aerobic activity for long durations, electrolyte-enhanced beverages may be helpful for hydration.
3. Coffee and tea. Both non-caffeinated and caffeinated coffee and tea beverages can contribute to hydration, without a diuretic effect, says Kenefick. Moderate intakes of coffee or tea have been linked with a variety of health benefits, from cancer protection to enhanced mental performance. Additionally, tea has been linked to heart health, weight loss and even bone protection. Keep in mind that high intakes of caffeine can lead to side effects in some people, such as anxiety, irritability, insomnia, uneven or rapid heart rate and stomach upset.
4. Alcohol. Even alcohol contributes to your daily fluid needs. "But, there is a caveat," says Kenefick. "Concentrations of 12 to 14 percent alcohol, such as liquor and wine, do contribute to dehydration by increasing urine output. Fluids with lower alcohol concentrations, such as beer, tend to not have that effect." Moderation (up to one drink per day for women and two drinks for men) is the key to health when it comes to alcohol. One drink is considered 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of hard alcohol.
5. Sweetened beverages. Research indicates that sugar-sweetened beverages, including sodas and artificially flavored "fruit" drinks--rich in calories through readily absorbable sugars--may contribute to chronic diseases. While these beverages may help to meet your hydration needs, it's best to limit them.
6. Zero-calorie sodas. Artificially sweetened beverages are under scrutiny for their role in increasing the risk for obesity and other risk factors, such as stroke and heart attack. It's a good idea to limit this drink, which provides no nutritional benefits.
7. High fluid foods. Approximately 80 percent of total water comes from beverages and 20 percent comes from food, according to the Institute of Medicine. Some foods, such as fruits and vegetables, contain high amounts of water. Research from the University of Kentucky indicates that red tomatoes, radishes, strawberries, and cantaloupe, for example, consist of 94, 95, 92 and 90 percent water, respectively.
If your fluid intake is inadequate and you develop dehydration, it can lead to cardiovascular strain, compromised physical and mental performance, and even heat stroke. "Studies consistently show that dehydration results in mood changes, including anger, confusion, fatigue and vigor," adds Kenefick.
Yet, dehydration is a common occurrence, even among healthy individuals. Older adults, particularly those over age 71, are at even higher risk for dehydration, according to data on fluid intake from the Third National Health and Nutrition Examination Survey. This could be due to multiple reasons, including changes in body water composition, alterations in thirst perception, impaired kidney function, and even reduced appetite and the subsequent reduced food intake.
It seems that the body's thirst mechanism is not the most reliable, especially during exercise. According to Kenefick, by the time the brain registers thirst during exercise, you may already be dehydrated. And as exercise continues, it can be difficult to achieve adequate rehydration.
This article was written by McKenzie for the August, 2014 issue of Environmental Nutrition.