A new study in mice has shown that limited intake of a certain essential amino acid slows the effects of aging and even extends life. Scientists are now interested in whether these findings could help increase the length and quality of people’s lives.

Isoleucine is one of three branched-chain amino acids that we use to create proteins in our bodies. It is essential for our survival, but since our cells cannot produce it from scratch, we must obtain it from sources such as eggs, dairy products, soy protein and meat.

But there can always be too much of a good thing. Previous research using data from the 2016-2017 Wisconsin Resident Survey found that isoleucine levels in foods were associated with metabolic health, and that people with higher BMIs tended to consume much more of the amino acid.

“Different components of your diet have value and impact beyond their function as calories, so we investigated one component that many people may be consuming too much of,” says Dudley Lumming, a metabolism researcher at the University of Wisconsin in the US who was involved in the study. study. both studies.

“It’s exciting and encouraging to think that a change in diet, even if it starts around middle age, can make such a big difference in lifespan and what we call ‘healthiness’.”

A genetically diverse group of mice were fed a diet containing a total of twenty amino acids as a control, a diet in which all amino acids were reduced by approximately two-thirds, or a diet in which only isoleucine was reduced by the same amount. At the beginning of the study, the mice were about six months old, which corresponds to the age of a 30-year-old human. They could eat as much as they wanted, but only the specific types of food provided to their group.

Dietary isoleucine restriction increased the lifespan and health of mice, reduced their wasting, and promoted leanness and glycemic control. Male mice had a 33 percent longer lifespan than those without isoleucine restriction, while female mice had a 7 percent longer lifespan. These mice also performed better on 26 health parameters, including muscle strength, endurance, blood sugar, tail use and hair loss.

Male mice in this group had less age-related prostate enlargement and were less likely to develop cancerous tumors, which are common in different mouse species. Interestingly, mice fed a diet low in isoleucine consumed significantly more calories than the others. But instead of gaining weight, they actually burned more energy and maintained a lower body weight, even though their activity levels were no different.

Researchers believe that limiting isoleucine in humans through diet or medication could potentially lead to similar anti-aging effects, but as with all mouse studies, we won’t know for sure until it’s actually tested in humans.

This is easier said than done. Although the food given to the mice was controlled, the researchers noted that the diet is an incredibly complex chemical reaction and it is possible that other dietary components played a role in achieving these results.

For example, restricting protein intake in general has harmful effects on mice or humans. Translating this research into the real world in humans is more difficult than reducing high-protein foods; however, this is the easiest way to limit isoleucine intake.

The level of amino acid restriction was constant throughout the experiments and they acknowledge that fine-tuning may be required for optimal effects in mice of different strains and sexes; When it comes to diet, one size does not fit all.

“We can’t just switch everyone to a low-isoleucine diet,” says Lamming. “But distilling these benefits down to a single amino acid brings us closer to understanding biological processes and perhaps potential interventions for humans, such as a drug that blocks isoleucine.” Source