Eating less can boost healthier ageing by protecting the body’s cells from harmful deterioration and the risk of cancer
Scientists know an extreme diet does not appeal to many people but say their discovery could lead to ways of mimicking its effects and pave the way for an “anti-ageing pill”.
Evolutionary biologist Dr Margo Adler, who led the research, said that cutting back on food leads to increased rates of “cellular recycling” and repair mechanisms in the body.
believes this evolved to help animals continue to reproduce when food is scarce. Their bodies adapt by recycling and reusing nutrients stored in the cells.
“This is the most intriguing aspect from a human health standpoint. Although extended lifespan may simply be a side effect of dietary restriction, a better understanding of these cellular recycling mechanisms that drive the effect may hold the promise of longer, healthier lives for humans.”
The process, known as autophagy, is essential to the survival of newborn babies when they suddenly lose their supply of nutrients from the placenta, but have yet to drink milk.
They bridge the gap by feeding on their own cells, breaking them down and releasing essential nutrients.
Increased cellular recycling could account for the longer lifespan of laboratory animals on very low diets.
“This effect has been demonstrated in laboratories around the world, in species ranging from yeast to flies to mice. There is also some evidence it occurs in primates.”
it may be possible to develop drugs that mimic the effect.
Writing in the journal Bio Essays, she said the most widely accepted theory is that it evolved to improve survival during times of famine. But “Most animals in the wild are killed young by parasites or predators.
“Since dietary restriction appears to extend lifespan in the lab, it is unlikely to have the same effect on wild animals, which generally do not live long enough to be affected by cancer and other late life pathologies.”
Scientists have known for decades that severely restricted food intake reduces the incidence of cancer and can even reverse diabetes.
People who restrict calories or combine diets with exercise usually improve their blood pressure, body fat and cholesterol levels, heart rate and weight.
These factors cut the risk of chronic diseases. But the side effects can include reduced bone density, memory loss, dizziness and depression.
In 2012, a study found that a low calorie diet can slow down ageing and ward off diabetes, cancer and dementia. Other studies have pointed to the need to cut food intake by about 40 per cent to live 20 to 30 per cent longer.