Some people will do anything to get out of doing exercise, and researchers are scrambling to oblige, showing physical health benefits – in mice and flies, that is – of isolated proteins that could potentially be taken in a pill.
Noting that a naturally occurring protein called Sestrin builds up in muscles after a heavy physical workout, scientists from the University of Michigan were curious to see if boosting Sestrin levels could produce the same health benefits without exercise.
They tested this in three groups of Drosophila flies, two of them bred either unable to produce Sestrin or saturated with it, and a normal group for comparison.
They were all put on a makeshift fly treadmill for three weeks.
“Flies can usually run around four to six hours at this point and the normal flies’ abilities improved over that period,” says researcher Jun Hee Lee.
But the flies without Sestrin showed no improvement with exercise, while those with maxed-out Sestrin levels showed superior abilities to the trained flies, even without working out – and exercising them didn’t increase their endurance.
They note studies with mice also found that Sestrin improved aerobic capacity, respiration and fat burning – all benefits associated with exercise.
Other researchers at Augusta University, US, targeted a different protein, myostatin, that inhibits muscle growth, testing lean and obese mice that couldn’t make the protein.
Both groups bulked up, but the obese mice had similar metabolic and heart health indicators to the lean mice, and better than obese mice that could produce myostatin.
“While much more research is needed, at this point myostatin appears to be a very promising pathway for protection against obesity-derived cardiometabolic dysfunction,” says researchers Joshua Butcher.
Assuming that you can extrapolate these findings to humans – which itself could be drawing a long bow – researcher and sports dietitian Karen Murphy, from the University of South Australia, expresses concern about replacing exercise with a pill.
“There are multitudes of benefits to physical activity beside burning muscle, like heart health, physical health, weight control, mental health and social interaction,” she says. Even cognitive decline can be buffered with exercise, as well as bone density.
And many other nutrients are essential for wellbeing and muscle mass.
“Most people consuming a balanced diet, with foods from all food groups in the right portions, will have little need for a supplement,” says Murphy.
“For some populations an added supplement that boosts muscle synthesis might help such as in elderly populations where muscle wasting is seen. However, to build muscle you also have to work the muscle.”
Essentially, for people who genuinely can’t exercise, there could be some benefits to pills – but they still can’t replace all the other benefits of moving your body.
Even incapacitated people with dementia can derive surprising benefits from personalised movement.
And in a world where people are moving less, getting active is more important than ever.