July 19, 2024
Obesity, Amino Acid, Health, Mice, low-isoleucine diet

New Study Shows that Eating Less of an Obesity-Associated Amino Acid Extends Lifespan and Improves Health in Mice

A recent study conducted by researchers at the University of Wisconsin School of Medicine and Public Health has found that reducing the consumption of a specific amino acid called isoleucine can have significant health benefits in mice. Published in the journal Cell Metabolism, the study showed that mice who ate fewer calories but consumed a diet low in isoleucine experienced longer lifespans, reduced frailty, and a lower risk of cancer and prostate problems.

Lead author of the study, Dudley Lamming, explains that while many people believe that all calories are the same, scientific evidence suggests that the different components of our diet have varied impacts on our health beyond their caloric value. The researchers focused on isoleucine, an essential amino acid found in eggs, dairy, soy protein, and meat, which was found to be consumed in excess by overweight individuals.

To investigate the effects of isoleucine on health, the researchers fed genetically diverse mice a balanced control diet, a low-amino-acid diet, or a diet that eliminated two-thirds of the isoleucine content. Despite being allowed to eat as much as they desired, the mice on the low-isoleucine diet quickly lost body fat and became leaner. These mice also lived longer, with male mice experiencing a 33% increase in lifespan and female mice living 7% longer.

The mice on the low-isoleucine diet also showed significant improvements in health compared to the other groups. They exhibited greater muscle strength and endurance, had better tail use, experienced less hair loss, and maintained stable blood sugar levels. Additionally, male mice on the low-isoleucine diet had a reduced risk of age-related prostate enlargement, and both genders were less likely to develop tumors.

Previous studies have shown that restricting calories and protein intake can increase lifespan in young mice. However, this study demonstrated that even when initiated in midlife, a dietary change, specifically reducing isoleucine intake, can still have substantial benefits on both lifespan and “healthspan.”

Interestingly, the mice on the low-isoleucine diet consumed more calories than the other groups, likely due to their bodies compensating for the reduced isoleucine content. However, these mice also burned more calories, resulting in the maintenance of a leaner body weight through metabolic adjustments rather than increased exercise.

The researchers believe that the effects of isoleucine on longevity and health could be attributed to its connection to a gene called mTOR, which plays a role in the aging process in animals. Furthermore, isoleucine is linked to a hormone that regulates the body’s response to cold and has been considered as a potential candidate for diabetes treatment. However, the specific mechanism behind the benefits of reducing isoleucine intake requires further investigation.

While the results are promising, the researchers note that humans still require isoleucine for survival. Implementing a low-isoleucine diet in humans is challenging as it would involve extensive dietary modifications. Nonetheless, understanding the biological processes associated with isoleucine intake may eventually lead to interventions, such as isoleucine-blocking drugs, that can improve health outcomes in humans.

The researchers also observed that lean individuals tend to consume lower levels of isoleucine compared to overweight individuals. This suggests that making healthier food choices and adopting a healthier eating pattern may naturally lower isoleucine intake, potentially providing similar health benefits observed in the study.


  1. Source: Coherent Market Insights, Public sources, Desk research
  2. We have leveraged AI tools to mine information and compile it