Australian scientists have helped turn back the body clock for elderly mice, and hope this could ultimately lead to an anti-ageing pill that would mimic the benefits of exercise.In a five-year study, released Friday, scientists fed a compound called nicotinamide mononucleotide (NMN) a form of vitamin B3 that is naturally produced by the body – to elderly mice. The compound increased muscular blood flow, enhanced physical performance and endurance, and the elderly mice became as fit and as strong as the younger ones.
The results of the experiment, which involved a team of academics from Harvard, Massachusetts Institute of Technology and the University of New South Wales, were published in the Cell journal on Friday.
“NMN can make the old cells healthy, and it can increase capillaries and blood flow,” says Dr Abhirup Das, the study’s lead author and an anti-ageing researcher at the University of NSW. “The work points to ways to mimic exercise, reverse ageing, and restore the body’s ability to respond to exercise in a single pill,” says Dr David Sinclair, head of laboratories at Harvard Medical School Boston and the paper’s senior author.
But the experiment was performed on mice, and even the best trials using the small mammals only translate to humans a third of the time. And Dr Sinclair and his team have already seen one much-hyped anti-ageing drug flame out in human trials.
Dr Sinclair discovered the anti-ageing properties of a red-wine compound called Resveratrol in 2003. That work got him into Time magazine’s 2014 list of the world’s most influential 100 people.
But Resveratrol research stalled somewhat after human trials revealed the high concentrations needed to have an effect caused diarrhoea.
He now believes NMN can do what Resveratrol couldn’t. In theory, here’s how it could wind back the clock.
As you age, your body gets worse at circulating blood. It largely stops building capillaries, the tiny vessels that carry blood through the tissue. Your cells are starved of oxygen and nutrients, and you feel weak and frail.
Our body converts NMN into another compound called NAD+, which is a well-studied anti-ageing molecule. NAD+ fuels an important gene, SIRT1, that keeps us young and healthy. For some reason, NAD+ levels fall as we age.
Falling NAD+ levels are strongly linked to reduced response to exercise. With low levels, no matter how hard you exercise, you’ll never grow stronger. In the latest trial, Dr Sinclair’s team spiked the drinking water of elderly mice with NMN. Their bodies responded, building new capillaries and pumping blood back into fading muscles. Soon, they were running on their wheels like young squeakers. Exercise is the best way of slowing this process, but our body’s response to exercise declines as we age.
NMN is exercise, in a pill “The effects of ageing on the mouse capillaries”, the study concludes, “were surprisingly easy to reverse”.
Compounds with anti-ageing properties have been stymied by the human digestive system’s habit of breaking up the molecule before it can have any effect. Resveratrol failed in part because the liver broke it down before it could have any effect. But NMN metabolises straight into NAD+, which can then hit the target. When that was discovered a few years ago, the previously ignored compound suddenly became the focus of study around the world.
Phase one human trials of NMN were completed in Boston last year, showing that the compound was safe for consumption. Phase two, looking at its effectiveness, will begin later this year.