Two newly published studies investigate the enticing possibility that we might one day be able to gain the benefits of exercise by downing a pill, rather than by actually sweating, The New York Times reports.
One of the new studies, published this week in the journal Nature Medicine, was conducted by researchers at the Scripps Research Institute in Jupiter, Fla., who reported a compound they had created and injected into obese mice increased activation of a protein called REV-ERB, which caused them to lose weight, even on a high-fat diet, and improved their cholesterol profiles.
The treated mice also began using more oxygen throughout the day and expending about 5 percent more energy than untreated mice, even though they were not moving any more than the other animals. The drug, it seemed, was providing them with a workout, minus the effort.
The drug "certainly seems to act as an exercise mimic," said co-author Thomas Burris, M.D., now the chairman of the department of pharmacological and physiological science at St. Louis University School of Medicine, told The New York Times.
A second study, published this month in the journal PLOS Biology, by scientists at the Washington University School of Medicine in St. Louis tried to replicate earlier work showing that resveratrol, the chemical found abundantly in grape skins and red wine, increases the creation of new mitochondria in isolated muscle cells, mimicking aerobic exercise. After those earlier studies, resveratrol, too, had been hailed as a means of counterfeiting exercise pharmacologically.
But the new study punches holes in that hope. When the scientists fed both rats and mice medically tolerable levels of resveratrol in their kibble, the animals did not produce more mitochondria in muscle cells. Only at extremely high doses did resveratrol lead to more mitochondria.
Unfortunately, at these exaggerated doses, the substance has a "toxic effect," said John O. Holloszy, M.D. a study co-author and professor of medicine at Washington University.
Still, the dream of effortless fitness remains alluring. "I know there are probably plenty of people who would prefer" to pop a pill rather than jog a few miles, Dr. Burris said.