Isoleucine is one of the essential protein amino acids, which means that the human body cannot synthesize it and must obtain it through diet. A new study indicates that reducing it increases life expectancy.
In the constant search for a healthy lifestyle, the saying “You are what you eat” resonates louder than ever. In a world where food options are numerous but not always healthy, the link between diet and health has become a central subject.
In general, it is believed that “a calorie is a calorie”, which refers to the idea that from a body weight perspective, weight loss or gain depends primarily on the balance between calories in and calories out, regardless of the source of those calories. So, if you consume more calories than you burn, you will gain weight, and if you consume fewer calories than you burn, you will lose weight.
However, Following a low-calorie diet can be difficult, and this simplified statement doesn’t take into account other important factors that can influence weight loss or gain. , such as food quality, diet composition, satiety and hormonal response. Research suggests that not all calories are equal in terms of their impact on appetite, metabolism and body composition.
In this line, a new study recently published in the magazine Cellular metabolism, discovered that Reducing the consumption of an amino acid, isoleucine, by two-thirds improved the life expectancy, weight and health of middle-aged mice without the need to reduce their calorie intake.
“We like to say that one calorie No It’s just one calorie.” said Dudley Lamming, principal investigator of the study and professor and metabolism researcher at the University of Wisconsin-Madison (UW-Madison) School of Medicine and Public Health. release.
Isoleucine is one of the nine essential amino acids for humans, meaning the body cannot synthesize it itself and must obtain it through diet. It is a fundamental protein component that plays several important roles in the body, and Lamming and his colleagues are interested in its connection to healthy aging.
“Different components of your diet have value and impact beyond their calorie function, and we studied one component that many people might be overeating.” said the lead author.
In previous research, data from the UW-Madison Wisconsin Health Survey found that people with a higher body mass index tended to consume more isoleucine, which is abundant in foods like eggs, dairy, soy protein and many types of meats and leaner participants tended to follow a diet low in isoleucine.
“It may be that by choosing healthier foods and eating healthier in general, we can reduce isoleucine enough to make a difference,” Lamming said.
To better understand the health effects of isoleucine, researchers from across disciplines at UW-Madison fed three different diets to genetically diverse mice: a balanced control diet containing all 20 common amino acids; a version of the balanced diet with a low content of amino acids; and a diet formulated to eliminate two-thirds of isoleucine from the diet .
The mice began the study at around 6 months of age, which is equivalent to a 30-year-old person, and ate as much as they wanted. “Very quickly, we noticed that mice subjected to a diet reduced in isoleucine lost adiposity: their body learned and lost fat,” Lamming said. Compared to mice that were on a diet low in amino acids, they initially lost weight, but regained weight and fat.
“Previous research has shown that lifespan increases with a diet low in calories, protein or amino acids, starting in very young mice,” said Lamming, whose work is supported by the US National Institutes of Health “We started with mice that were already aging. “It’s interesting and encouraging to think that a change in diet could still make such a big difference in life expectancy and what we call ‘healthy life expectancy,’ even as it begins to decline. closer to middle age.”
According to Lamming, mice on a low-isoleucine diet consumed significantly more calories than their study counterparts, likely in an attempt to compensate for lower isoleucine consumption. But they also burned significantly more calories, lost some, and then maintained a leaner body weight simply by adjusting their metabolism, not by exercising more.
The results indicate that Mice on a diet low in isoleucine lived longer: on average, 33% longer for males and 7% longer for females. And, based on 26 health metrics, including assessments ranging from muscle strength and endurance to tail use and even hair loss, Mice with low levels of isoleucine were in much better shape throughout their long lives.
The mice also maintained better blood sugar control, and the male mice had less age-related prostate enlargement. And although cancer was the leading cause of death in the genetically diverse mice used in the study, males fed low levels of isoleucine were less likely to develop a tumor.
In particular, a diet reducing all amino acids, including isoleucine, has been shown to improve some aspects of lifespan in both sexes and reduce frailty to the same extent as a diet low in isoleucine, but did not extend the lifespan. female mice.
Researchers don’t yet fully understand the big benefits of low isoleucine intake, but Lamming believes that The results of the new study could help future research identify the causes.
Although the results are promising, humans need isoleucine to live. “We can’t just put everyone on a low-isoleucine diet. » Lamming said. “But reducing these benefits to a single amino acid brings us closer to understanding biological processes and perhaps possible interventions for humans, such as an isoleucine-blocking drug.”