Health & Wellbeing

The reason a calorie-restricted diet extends your lifespan is in your genes

The reason a calorie-restricte...
Researchers may have found the answer to why eating less can help you live longer
Researchers may have found the answer to why eating less can help you live longer
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Researchers may have found the answer to why eating less can help you live longer
Researchers may have found the answer to why eating less can help you live longer

You've probably seen some headlines in recent years heralding the correlation between a lowered caloric intake and increased lifespan. The topic has been a rich area of research for decades, but scientists have been unable to successfully explain the phenomenon. New research from a team at Temple University may have finally cracked the puzzle by revealing that epigenetic changes that occur with age can be slowed through a calorie-restricted diet.

The research focused on the process of DNA methylation, a chemical activity that essentially directs when a gene should or shouldn't be expressed. These methylation patterns were found to shift as an animal ages, increasing and decreasing in different genomic areas.

"Our study shows that epigenetic drift, which is characterized by gains and losses in DNA methylation in the genome over time, occurs more rapidly in mice than in monkeys and more rapidly in monkeys than in humans," says senior investigator Jean-Pierre Issa.

Using deep-sequencing technology the team first studied how age-related variations in DNA methylation were correlated with an animal's lifespan. It was discovered that the greater the epigenetic change from methylation, the shorter the animal's lifespan.

Knowing that a great deal of research has already shown how calorie restriction can increase lifespan, the focus of the study then moved on to examining whether reduced dietary calories had a direct effect on epigenetic drift.

Groups of rhesus monkeys and mice fed calorie restricted diets both displayed reduced evidence of epigenetic drift when compared to similar control groups eating an average caloric volume. The rhesus monkeys, eating a diet with 30 percent less calories than normal, displayed a blood methylation age equivalent to animals seven years younger.

The results were even more pronounced in the mice studies, which the researchers suggest is related to the animal's shortened lifespan (allowing for a restricted diet to be imposed over the animal's entire life), and the increased restriction of the diet (which was increased to a 40 percent caloric reduction).

"The impacts of calorie restriction on lifespan have been known for decades, but thanks to modern quantitative techniques, we are able to show for the first time a striking slowing down of epigenetic drift as lifespan increases," says Issa.

As well as offering a key insight into how a caloric restricted diet could increase a person's lifespan, the research highlights how modifying the body's natural epigenetic drift process could have significant impacts on preventing age-related diseases.

Questions over what causes this epigenetic drift to occur more rapidly in some people over others are now primary areas of investigation for the researchers, with the next step to begin examining what other factors could impact on this process.

The study was published in the journal Nature Communications.

Source: Temple University

Brian M
Wonder if this is an evolutionary trait, there could be a Darwinian logic to it: Plenty of food then chances of having surviving offspring increases, so older animal could put the group at a disadvantage.
Conversely, in a time of famine, less chance of your offspring surviving so essential adult creatures survive longer. ?
In 1999 Dr Ron Rosedale wrote a paper called "Insulin and it's Metabolic Effects" where he postulated that 'Insulin' is a substance that "Keeps you alive but kills you". Apparently he accidentally dropped Insulin onto blood vessels in the lab and the Insulin caused plaque buildup similar to hardening of the arteries. In the paper he goes on to say that every time you eat a fast carb (sugar, starch...) that pushes your blood sugar level beyond the toxicity threshold, Insulin is secreted to bring the blood sugar level back down, at the same time converting the excess sugar into body fat. In other words, "Insulin keeps you alive (short term) but kills you (long term)!". Could this be the real reason a calorie-restricted diet extends your lifespan?
Just recently read that eating cooked bean can give similar results as calorie restrictions.
Be interesting to look at the diet fed to these research animals to discern an important factor.