Elixir of youth has been found - for mice
SCIENTISTS in the US claim to have discovered a natural compound found in avocado, broccoli and cucumber that has "remarkable anti-ageing effects in mice" - and could also work on humans.
The researchers, who have started clinical trials involving a small group of people, said older mice given the compound, called NMN, in their water saw an array of beneficial effects. Their level of physical activity increased, bone density and muscles improved, the immune system and liver performed better, their eyesight improved and they even lost weight.
The researchers began investigating the properties of a protein called NAD, which is involved in energy production in the body.
As animals get older, they produce less NAD and it is thought this is a part of the ageing process. Attempts to add extra NAD failed, so the researchers looked for a way to boost its production in the body.
They gave mice NMN, also found in cabbage and edamame, in their drinking water to see if this would boost levels of NAD and have a rejuvenating effect.
Asked if this worked, lead researcher Professor Shin-ichiro Imai, of Washington University in St Louis, said: "The answer is basically yes. As a matter of fact, NMN has remarkable anti-ageing effects in mice.
"Those NMN [fed] mice definitely have longer health-span - entire lifespan, we're not sure, but if this keeps working in this way they could have a longer lifespan as well.
"We have shown a way to slow the physiologic decline that we see in ageing mice. This means older mice have metabolism and energy levels resembling that of younger mice."
And he expressed optimism that the clinical trials with human subjects, underway in Japan, would produce similar results.
"Since human cells rely on this same energy production process, we are hopeful this will translate into a method to help people remain healthier as they age," he said.
However, while there was no sign of it in the study, there could be a significant catch - NAD might also give an energy boost to cancer cells.
"Some tumour cells are known to have a higher capability to synthesise NAD, so we were concerned that giving NMN might increase cancer incidence," Professor Imai said. "But we have not seen any differences in cancer rates between the groups [of mice]."
The researchers, who reported their results in a paper in the journal Cell Metabolism, added the benefits were only experienced by older mice.
"When we give NMN to the young mice, they do not become healthier young mice," said Professor Jun Yoshino, who also took part in the research. "NMN supplementation has no effect in the young mice because they are still making plenty of their own NMN.
"We suspect that the increase in inflammation that happens with ageing reduces the body's ability to make NMN and, by extension, NAD."
A statement about the research issued by Washington University said "high-grade NMN" for human consumption was not commercially available at present, but added "there's always broccoli".
Earlier this year, a different team of scientists revealed they had managed to extend the lifespan of mice by 35 per cent by removing "worn out" cells from the body that have a destructive effect.