A low-calorie diet is the key to youth, scientists claim

Researchers at the University of California, Irvine, analyzed how aging affects our circadian rhythm - the body's 'clock' - and slowly derails metabolism over time.

A low-calorie diet may be key to youth, scientists claim after finding the link between the body's biological clock and aging.

Researchers at the University of California, Irvine, analyzed how aging affects our circadian rhythm - the body's 'clock' - and slowly derails metabolism over time.

Ultimately, they found a low-calorie diet was the best thing to keep the cells' energy-regulation process 'humming', keeping the body younger. 

Lead author Dr Paolo Sassone-Corsi said the study presents a 'molecular holy grail' that clearly shows the cellular pathway that controls aging.   

Researchers at the University of California, Irvine, looked at how aging affects the control of metabolism and found a low-calorie diet helps keep the body younger (stock image)

Researchers at the University of California, Irvine, looked at how aging affects the control of metabolism and found a low-calorie diet helps keep the body younger (stock image)

'The findings provide a clear introduction on how to go about controlling these elements of aging in a pharmacological perspective,' Dr Sassone-Corsi explained. 

The clock-controlled circuit that directly connects to the process of aging is based on the cells efficient metabolism of energy.

The researchers tested the same group of mice at six months and 18 months, drawing tissue samples from the liver, the organ which operates as the interface between nutrition and energy distribution in the body.

They found that older cells processed energy inefficiently.   

RESEARCHERS SUCCESSFULLY MAKE OLD CELLS YOUNGER

Researchers have developed technology to reverse the ageing of cells.

The breakthrough came as a surprise to researchers who were investigating a cure for progeria, a genetic disorder that causes children to age rapidly and die before they reach their late teens. 

Experts insist the findings could transform our understanding of - and approach towards - treatment of ageing.  

Lead investigator Dr John Cooke, department chair of cardiovascular sciences at Houston Methodist Research Institute, said it was like night and day. 

'We looked at many cellular markers of aging and weren't expecting to see such a dramatic effect on them. Our approach had a much greater effect on all the markers of cellular aging,' he said.

'We markedly improved the ability of cells to multiply and reversed the production of inflammatory proteins. Those markers of cell aging we looked at were all reversed with the treatment in our study.' 

They focused on progeria since the disease can offer insight into the way all human cells age, but on an accelerated basis.  

But in a second group of aged mice that were fed a diet with 30 percent fewer calories for six months, energy was processed in a more stable way. 

More simply put, researchers found that calorie meals help the body metabolize energy more efficiently and keep people looking and feeling younger.

Dr Sassone-Corsi, director of the Center for Epigenetics and Metabolism at the university, said: 'This mechanism works great in a young animal, but it basically shuts off in an old mouse.'

He also explained that by restricting caloric intake, the biological clock was rejuvenated. 

Things that can be done to reduce daily calorie count are switching out fried foods for things that are baked, opting for fruits and vegetables over starches and carbs, and avoiding sugary drinks in favor of water.  

'In this context, a good clock meant good aging' Dr Sassone-Corsi said. 

In a companion study, also published in Cell, a research team from the Barcelona Institute for Research in Biomedicine collaborated with the Sassone-Corsi team to test body clock functioning in stem cells from the skin of young and older mice.

They too found that a low-calorie diet conserved most of the rhythmic functions that preserve youth.

Professor Salvador Aznar Benitah, who co-led the Spanish study, 'The low-calorie diet greatly contributes to preventing the effects of physiological aging.

'Keeping the rhythm of stem cells "young" is important because in the end these cells serve to renew and preserve very pronounced day-night cycles in tissue.

'Eating less appears to prevent tissue aging and, therefore, prevent stem cells from reprogramming their circadian activities.'

Both groups of researchers said the studies can help explain why a calorie-restricted diet slows down aging in mice.

And they say that implication for humans could be far-reaching.

The scientists said it's important to further examine why metabolism has such a dominant effect on the stem cell aging process. 

Then once the link that speeds up or slows down the human body clock is found, to develop treatments that can regulate the link.

It has been shown in previous fruit fly studies that low-calorie diets can extend longevity, but the new research is the first to show that calorie restriction influences the body's circadian rhythms' involvement with the aging process in cells. 

Dr Sassone-Corsi and his colleagues first showed the circadian rhythm-metabolism link some 10 years ago, identifying the metabolic pathways through which a circadian enzyme protein called SIRT1 works.

The SIRT1 protein senses energy levels in cells and its activity is adjusted by how many nutrients a cell is consuming.

It also helps cells resist oxidative and radiation-induced stress, and has been tied to the inflammatory response, diabetes and aging.