Grab your nose plugs - the smell of food could be ageing you

The smell of food could interfere with the body’s anti-ageing processes‚ much like eating does‚ a new laboratory study shows.

Limiting how much you eat without starving extends the lifespan in more than 20 species‚ scientists have proven. What's not known is how this works.

The latest research suggests that it’s not just what you eat‚ but even whether you smell food‚ which could affect the ageing process.

The worm experiment reinforces previous results of research on fruit flies. This found fruit flies lived longer on a restricted diet but not as long when they were allowed to smell the food.

While fruit flies and worms are far down the evolutionary chain from humans‚ what’s happening to them at a molecular level could shed light on human ageing.

The study's corresponding author‚ Professor Kailiang Jia from the Brain Institute at Florida Atlantic University in the US‚ said: “When people are on a diet‚ they might say something like 'I didn't eat a lot of food.'

“Except it's not only the calories that count‚ but also the smell of food that can influence the function of the brain and the GI tract.”

The scientists were investigating the process of autophagy — how the cells consume the garbage they produce through metabolism‚ which impacts on ageing.

Autophagy works in the brain and the intestine‚ and smell influences this‚ these scientists have reported.

Increasing autophagy combats disease and decreasing this process exacerbates it.

Professor Valter Longo‚ director of the Longevity Institute at the University of Southern California‚ in 2015 released results on a five-day semi-fast‚ which he reported boosted longevity.

He found that fasting for more than three days appeared to switch the body into anti-ageing and repair mode and to lead to the burning of abdominal fat.