The ‘exercise pill’ could deliver fitness benefits in a tablet
For those who can’t exercise, this might be the answer: rather than spending hours in the gym, the benefits of physical training could be delivered in a tablet.
The prospect of an ‘exercise pill’ could be music to the ears of couch potatoes, long-haul truck drivers and stressed-out office workers, but researchers believe it could transform the lives of incapable people. exercising because of obesity or serious health problems. physical disabilities.
Hopes for such a pill emerged Tuesday from scientists who found that an experimental drug allowed mice to run on a treadmill for 270 minutes before exhaustion set in. The mice without the drug lasted only 160 minutes before reaching their physical limit.
Scientists found that increased endurance was accompanied by other apparent health benefits, causing mice who took the drug for eight weeks to gain less weight and better control their blood sugar levels, suggesting that a pill could also help people with diabetes.
Scientists led by Ronald Evans of the Salk Institute in San Diego made the discovery after setting out to explore what endurance meant at the molecular level. “If we really understand the science, can we replace training with medicine? ” he said.
They turned to a drug known as GW501516, which was previously shown to improve stamina and burn fat faster. Through a series of tests with mice on treadmills, Evans found that the drug altered the activity of nearly 1,000 genes. Many genes that became more active were involved in the breakdown and burning of fat. But other genes have been removed, including some that convert sugar into energy.
Writing in the journal Cell Metabolism, the scientists describe how the findings could explain why runners, cyclists, and other athletes can “hit the wall” when they push each other hard. The drug allows the body to burn fat faster, but also burn sugar more slowly. The result is that, on the drug, the drop in blood sugar level that is responsible for the feeling of hitting the wall occurs much later than normal.
“In endurance sports competitions, such as cycling, marathons, walking and cross-country skiing, ‘hitting the wall’ is a dramatic display of sudden and complete exhaustion,” the scientists write. But the drug, which works through muscle proteins called PPARD, “is enough to dramatically improve endurance capacity.”
“Exercise activates PPARD, but we show that you can do the same without mechanical training. This means that you can improve your endurance to the level equivalent to that of a person in training, without all the physical exertion, ”said Weiwei Fan, the first author of the article.
The compound was originally developed by what is now GlaxoSmithKline and a US company called Ligand Pharmaceuticals in the 1990s. Intended to treat metabolic and cardiovascular disease, it was later discontinued, apparently after a number of studies have shown that high doses can cause cancer.
But despite the drug being discontinued commercially, scientists continue to study the compound. Ten years ago, animal testing showed it could potentially increase endurance. The discovery spawned a black market for the drug, and its subsequent abuse by some athletes at the 2008 Beijing Olympics. The following year, the World Anti-Doping Agency banned the drug and warned it was not safe.
Ali Tavassoli, professor of chemical biology at the University of Southampton who was not involved in the latest study, said any “exercise pill” developed by scientists could potentially be abused, not only by athletes, but also by horse trainers and others.
“But there are groups of people who for one reason or another can’t exercise, people with real problems, and you could potentially have a pill that gives them some of the benefits of it. exercise, ”he said. “A pill like this could give them a place where they can start exercising for real.”
Tavassoli is not convinced, however, that an exercise pill will arrive anytime soon. “Personally, I am not sure that such a pill is possible. There is a big difference between showing an organism that you can mimic exercise in the short term and showing the long term effects of doing so.
“An obese or diabetic person can take a pill for 40 or 50 years. What happens when you take a drug like this for such a long time? What happens to you ? These are big unanswered questions, ”Tavassoli said. “I don’t see these things getting regulatory approval.”
Louise MacKenzie, a pharmacologist at the University of Hertfordshire who has studied GW501516, said it was once considered a “wonder drug” because of its potential to treat a number of medical conditions. But while the compound appears to have benefits at low doses, it can have harmful side effects at high doses.
“It goes from being remarkably healthy to being quite the opposite, there is no in-between,” she said. Nonetheless, MacKenzie said the drug was a good “starting block” for scientists hoping to find new ways to treat patients. “I can definitely see a future where the problems are solved. You just need to have enough smart scientists working there, ”she said.