In 2014, Dudley Ramming was reading a book. Study from Australia It looked at how mice responded to dozens of controlled diets, and what caught his attention was that the mice with the lowest protein intake were the healthiest.
“This was really interesting because it goes against a lot of the health information people get,” said Ramming, a metabolic researcher at the University of Wisconsin School of Medicine’s School of Public Health.
Since then, Ramming and his lab graduate students have been trying to answer the questions posed by Australian studies. Why does a low-protein diet make animals healthier?
They have found lesser-known but certain patterns in both animal models and humans. A diet high in BCAAs, the three branched-chain amino acids, is associated with diabetes, obesity, and other metabolic disorders. Conversely, a diet low in BCAAs can combat these metabolic disorders and even extend healthy life expectancy in rodents.
It’s not yet entirely clear how BCAAs regulate metabolism, but limiting BCAAs seems to accelerate metabolism and promote healthier glycemic control. Also, diet-related studies in humans. Is so complex that the full impact of BCAA restrictions on humans is not yet known.
But a series of studies provide an interesting new way to think about what we eat. Studies have shown that a low-protein diet reprograms metabolism even when animals eat the same or more calories.
“There is a growing awareness that calories are more than just calories, they mean more than just the content of calories,” says Lamming. “Our research shows that protein calories are not the same as other calories.”
It’s better to have less
Scientific evidence of the benefits of both calorie restriction and protein restriction dates back almost a century, and the field has grown in recent years. In 2009, Researchers at the University of Wisconsin-Madison We have shown that rhesus monkeys on a long-term calorie-restricted diet live longer. Study with other animals It shows similar results.
A protein-restricted diet did not receive much fanfare. However, there is evidence that many of the benefits of calorie restriction can be achieved simply by limiting protein intake. These benefits last as long as the animal eats as much as it wants.
In two studies published earlier this year, Lamming and his colleagues, including graduate students Nicole Richardson and Deyang Yu, focused specifically on branched-chain amino acid restriction. BCAAs make up three of the nine essential amino acids that humans can’t make and eat. As the name implies, their chemical structure has tree-like branches. is included.
In a series of experiments published in January, Richardson tested mice with a diet containing only one-third of the normal BCAAs. It was not a calorie restricted diet. I could eat as many animals as I wanted.
Male mice that ate this diet lived on average about 30% longer and about 8 months longer. Other studies suggest that female mice may require a slightly different diet to benefit from reduced BCAA intake, but why female mice are effective. It’s not clear if it wasn’t shown.
Gender differences were “very amazing to us,” says Lamming. “Most of the studies so far have been done in male mice, which demonstrates the importance of doing these studies in both sexes.”
However, male mice showed reduced activity in a biochemical pathway known as mTOR activated by BCAAs. Many experiments have shown that treatments that reduce mTOR activity tend to improve metabolic health and prolong lifespan.
In another treatise Issued in May, Yu and Richardson dig deeper. They asked if the three individual BCAAs, leucine, isoleucine, and valine, had their own effects in the body, or if they all worked the same.
“We have found that isoleucine restriction has a much stronger effect,” says Lamming. Mice fed a low isoleucine diet were leaner and showed healthier glycemic metabolism. A valine-restricted diet had a similar effect, but a weaker effect. Lowering leucine levels has no benefit and may even be harmful.
To study how the three BCAAs affect obesity, researchers gave mice a so-called Western diet high in both fat and sugar. After several months of Western diet, mice become obese.
When Lamming’s group began feeding these obese mice a western diet low in isoleucine, mouse or rat I started eating more food, but I still lost weight. The main cause of weight loss is the speed of metabolism, and the body burns more calories as heat at rest.
Turning to human health, Ramming’s lab worked with SMPH Group Health professor Kristen Mareki and her colleagues to analyze the dietary diary and weight of participants in the Wisconsin Health Survey. public health Studies supported by the Wisconsin Partnership Program.
By calculating the number of amino acids each person ingested, they found that increased isoleucine intake was associated with increased anthropometric index. This was predicted based on rodent studies.
Rethinking the diet
Lamming recognizes that his research results are counterintuitive. Much of modern dietary advice recommends adding protein rather than limiting it. Protein promotes satiety and helps control calories.And for athletes who are building and repairing muscle, these are essential amino acid Is certainly essential.
However, because most of the U.S. population tends to be overweight and sedentary, Ramming sees an opportunity to rethink his diet: “Human beings are generally poor at adhering to a calorie-restricted diet for long periods of time. “He says. However, evidence from animal models suggests that a low-protein diet helps to lose fat even at normal caloric intake by reprogramming metabolism.
Many questions remain, especially when it comes to human low-protein diets. Studies of long-term controlled diets that ramming can do with rodents are almost impossible in humans. However, Ramming’s lab and other groups are working to test low BCAA diets in small human studies.
It is even difficult to develop a realistic low BCAA diet. Vegan diets are usually low in BCAAs and high in animal protein. However, more nutritional research is done, especially to make a low isoleucine diet. is needed. And because Americans usually consume more protein than they need, it can be difficult to change their habits.
“We have learned that the dietary composition of what you eat is really important for healthy life expectancy and longevity,” says Ramming. “And I think we’re on track. diet If you can protect your calories without limiting them, you can live a healthy and long life. ”
Samantha M. Solon-Biet et al, the ratio of major nutrients rather than caloric intake determines the health, aging, and longevity of cardiac metabolism in ad-lib-fed mice. Cell metabolism (2014). DOI: 10.1016 / j.cmet.2014.02.009
Deyang Yu et al, the adverse effects of branched-chain amino acids on metabolism are mediated by isoleucine and valine. Cell metabolism (2021). DOI: 10.1016 / j.cmet.2021.03.025
University of Wisconsin-Madison
Quote: Elucidating how a low-protein diet reprograms metabolism (June 11, 2021) June 11, 2021, https://medicalxpress.com/news/2021-06-uncovering-low-protein- Obtained from diets-reprogram-metabolism.html
This document is subject to copyright. No part may be reproduced without written permission, except for private research or fair trade for research purposes. The content is provided for informational purposes only.
Reveal how a low-protein diet reprograms metabolism
Source link Reveal how a low-protein diet reprograms metabolism