A recent study in mice has revealed that consuming limited amounts of a specific essential amino acid can actually slow the aging process and extend the lifespan of the animals.
Now, researchers are considering how this discovery could potentially be used for human health and longevity.
Isoleucine, one of the three branched-chain amino acids that are essential for building proteins in the human body, is considered vital for our survival. However, since our cells do not produce it naturally, we must obtain it from dietary sources such as eggs, dairy, soy protein, and meats.
Previous research, based on data from a survey of Wisconsin residents conducted between 2016-2017, found that levels of isoleucine were associated with metabolic health. Notably, individuals with higher body mass indexes tended to consume larger quantities of this amino acid. (source)
Dr. Dudley Lamming, a metabolism researcher from the University of Wisconsin, who was involved in these studies, points out that the findings underline the significance of considering various aspects of the diet beyond just calorie content. (source)
A diverse group of mice was fed different diets in the study—some with a reduced intake of all amino acids by about two-thirds, and some with a reduction only in isoleucine content. The outcome is that the mice with restricted isoleucine experienced an extension in lifespan, improved health, reduced frailty, and significant metabolic benefits.
Moreover, these mice showed improvements in various health markers such as muscle strength, endurance, blood sugar levels, tail use, and hair retention. Curiously, the mice also consumed more calories while remaining lean and energetic compared to the control group.
Despite these promising findings, the researchers caution that directly applying these results to humans is complex due to the multifaceted nature of diet and nutrition. They also acknowledge that further adjustments in the levels of amino acid intake might be necessary to optimize health benefits across different population groups.
While more studies are needed to fully comprehend the implications of these findings in humans, Dr. Lamming and his colleagues believe that this research brings us a step closer to understanding the potential health benefits of amino acid restriction in humans, and the development of drugs that can target specific amino acids.
The study has been published in Cell Metabolism 2023.
