What You Should Know about Sports Drinks
You've probably seen the commercials: your favorite sports figures guzzling sports drinks on TV, full-page ads in magazines spouting the virtues of downing a sugary sports beverage rather than water to prevent dehydration. What you should know about sports drinks, according to a new review in BMJ, is that there's little to no evidence to back up their use to keep you hydrated but lots of money to be made on the chances that you'll keep believing it.
Don't be fooled by sports drink claims
Every journey begins with the first step, and in the case of the current love affair with energy and sports drinks, the initial New York Marathon in 1970 is often named as that step and with launching the interest in road running. As more and more people took to the streets in running shoes and shorts, some companies and scientists were dashing to cash in on the phenomenon.
According to the expose in the new issue of BMJ, "companies have sponsored scientists, who have gone on to develop a whole area of science dedicated to hydration." These are the same scientists who then "advise influential sports medicine organisations, which have developed guidelines that have filtered down to everyday health advice."
That everyday advice is woven with an element of "fear about the dangers of dehydration." One of the products that feeds that fear is Gatorade, a sugary beverage that was developed originally to "prevent and cure dehydration, heat stroke, and muscle cramps, and improve performance."
Nothing feeds fear more than power, and today the sports and energy drink market has big guns behind it: PepsiCo bought Gatorade in 2001 and the drug company GlaxoSmithKline, as well as the beverage giant Coca-Cola, both have their own sports drink lines: Lucozade and Powerade, respectively.
To sell more sports drinks, the manufacturers had to make athletes and other active people believe they could not perform well without them. That meant the companies needed to team up with sports figures who would sing their praises, as well as scientists who could provide evidence that the products were necessary.
What followed was a series of guidelines and studies that had the touch of the sports drink market all over them--and behind them. In fact, a number of sports organizations and sports medicine publications have intimate ties with sports drink makers:
- The Australian Institute of Sport entered a partnership with Gatorade in 2004
- The US National Athletic Trainers' Association (with more than 35,000 members) works closely with Gatorade
- In 1992, the American College of Sports Medicine accepted a $250,000 donation from Gatorade
- In 1996, the American College of Sports Medicine issued guidelines in which it advised athletes to "drink as much as tolerable." Half of the guideline's creators either had a financial relationship with Gatorade or worked with the US military, which is the world's largest customer of Gatorade.
- Many journals have scientists on their editorial boards in prominent editorial roles who have ties with the makers of sports drinks. Among them is Medicine and Science in Sports and Exercise, which is owned by the American College of Sports Medicine and which has been financially linked with Gatorade and Powerade for many years. A senior editor of the journal has a longstanding financial relationship with Gatorade as well as Coca-Cola and GlaxoSmithKline.
- The Journal of Sports Sciences, which is the official journal of the British Association of Sports and Exercise Science, also has a financial relationship with Gatorade. Scientists with Gatorade also sit on the board of the Journal of Sports Science and the Journal of Applied Physiology.
One problem with the push for people to use sports drinks is that they often contain high amounts of sugar, which supports the claims that they provide energy. Another problem is that while they may offer some benefit for elite athletes, the makers of the beverages rarely do studies of ordinary people.
According to Professor Tim Noakes from the University of Cape Town, the sports drink makers "are never going to study a person who trains for two hours per week, who walks most of the marathon--which form the majority of users of sports drinks." Do these individuals really need to buy and consume sports drinks, or won't regular water provide the hydration they need?
Yet sports drink makers continually urge consumers to "stay ahead of your thirst" and to drink even when you're not thirsty, even though evidence indicates it's best to drink when you're thirsty.
Some sports drink makers have even suggested that their products can protect consumers against hyponatremia, a condition in which there is not enough salt in the body fluids outside the cells. When this happens, water moves into the cells in an attempt to balance the levels, which in turn causes the cells to swell. While most cells can manage the swelling, brain cells cannot.
One problem with this claim is that drinking too much of any liquid--water or sports drinks--can be dangerous to your health. Therefore implying that drinking lots of a sports drink will protect you against hyponatremia is misleading.
An investigative team at the Centre of Evidence Based Medicine at Oxford University decided to evaluate the evidence behind 431 claims of performance enhancing claims for 104 different sports products, including sports drinks, protein shakes, and trainers. The investigators found only three of the studies were of high quality and low risk of bias to be acceptable. They called these findings "worrying" and urged better research.
For millennia, people who were physically active drank water to rehydrate themselves. Now there is the science of hydration and the marriage of science and creative marketing slogans. According to the expose, what started out as a mixture of simple ingredients has become an "essential piece of sporting equipment" in a bottle.
The take-home message from the expose is to think before you drink. Do you really need that overpriced, hyped sports drink?
Cohen D. The truth about sports drinks. BMJ 2012;345:e4737 doi: 10.1136/bmj.e4737