Eating less slows the ageing process

Recent research offers one glimpse into how cutting calories impacts aging inside a cell. The researchers found that when ribosomes – the cell’s protein makers – slow down, the aging process slows too. The decreased speed lowers production but gives ribosomes extra time to repair themselves.

Ribosomes can be ‘expensive’ for the body to maintain – they use 10-20% of the cell’s total energy to build all the proteins necessary for the cell to operate. Because of this, it’s inefficient for the body to destroy an entire ribosome when it starts to malfunction. Instead individual parts of the ribosome are repaired on a regular basis to enable them to continue producing high-quality proteins for longer than they would otherwise and to keeps cells and the entire body functioning well.

Price likens them to cars: “The ribosome is a very complex machine, sort of like your car, and it periodically needs maintenance to replace the parts that wear out the fastest,” said Brigham Young University biochemistry professor and senior author John Price.

Younger for longer

So what causes ribosome production to slow down in the first place?

In a study published in Molecular & Cellular Proteomics Price and his team observed two groups of mice. One group had unlimited access to food while the other was restricted to consume 35% fewer calories, though still receiving all the necessary nutrients for survival.

“When you restrict calorie consumption, there’s almost a linear increase in lifespan,” Price said. “We inferred that the restriction caused real biochemical changes that slowed down the rate of aging.”

This study isn’t the first to make the connection between fewer calories and lifespan, but they were the first to show that general protein synthesis slows down and to recognize the ribosome’s role in facilitating those youth-extending biochemical changes.

“The calorie-restricted mice are more energetic and suffered fewer diseases,” Price said. “And it’s not just that they’re living longer, but because they’re better at maintaining their bodies, they’re younger for longer as well.”

The next step, say the researchers, will be to see if humans respond similarly, at a metabolic level, to calorie restriction. However, there is already good evidence in humans that reducing calorie intake can lead to better long term health. For instance in 2015 researchers found that reducing calorie intake by 25% below one’s regular intake  reduced the risk of several factors that influenced longevity, such as blood pressure, cholesterol, and insulin resistance.

“Food isn’t just material to be burned – it’s a signal that tells our body and cells how to respond,” Price said. “We’re getting down to the mechanisms of aging, which may help us make more educated decisions about what we eat.”