Posted on 03/25/2024 1:09:47 PM PDT by Red Badger
Research in mice shows limited intakes of one particular essential amino acid can slow the impacts of aging and even lengthen their lifespan.
Scientists are now wondering if these findings could help people improve their longevity and quality of life.
Isoleucine is one of three branched-chain amino acids we use to build proteins in our bodies. It is essential for our survival, but since our cells can't produce it from scratch, we have to get it from sources like eggs, dairy, soy protein and meats.
But there can always be too much of a good thing. Earlier research using data from a 2016-2017 survey of Wisconsin residents had found dietary isoleucine levels were linked with metabolic health and that people with higher BMIs were generally consuming much greater quantities of the amino acid.
"Different components of your diet have value and impact beyond their function as a calorie, and we've been digging in on one component that many people may be eating too much of," metabolism researcher Dudley Lamming from the University of Wisconsin, US, who was involved in both studies, explained in November when the new findings were published.
"It's interesting and encouraging to think a dietary change could still make such a big difference in lifespan and what we call 'healthspan,' even when it started closer to mid-life."
In the most recent study, a genetically diverse group of mice was fed either a diet containing 20 common amino acids as a control, a diet where all amino acids were reduced by about two-thirds, or a diet where only isoleucine was reduced by the same amount.
The mice were around six months old at the start of the study, which is the equivalent age of a 30-year-old person. They could eat as much as they wanted, but only from the specific kind of food provided to their group.
Restricting dietary isoleucine increased the lifespan and healthspan of the mice, reduced their frailty, and promoted leanness and glycemic control. Male mice had their lifespans increased 33 percent compared to those whose isoleucine was not restricted, and females had a 7 percent increase.
These mice also scored better in 26 measures of health, including muscle strength, endurance, blood sugar levels, tail use, and hair loss.
The male mice in this group had less age-related prostate enlargement, and were less likely to develop the cancerous tumors that are common in the diverse mice strains.
Curiously, the mice given low isoleucine food also ate significantly more calories than the others. But rather than gaining weight, they actually burned more energy and maintained leaner body weights, even though their activity levels were no different.
Graphical abstract shows dietary isoleucine was restricted by 67%, charts showing blood glucose and body weight declining over time / age respectively, reduced frailty and cancer, increased lifespan (survival improved by 33 percent)
A visual summary of the impact the reduced isoleucine diet had on mice in the study. (Green et al., Cell Metabolism, 2023)
The researchers think restricting isoleucine in humans, either by diet or pharmaceutical means, has the potential to yield similar anti-aging effects - although, as with all mice studies, we won't know for sure until it's actually tested in humans.
This is easier said than done. Although the food provided to the mice was controlled, the researchers noted that diet is an incredibly complex chemical reaction, and there may be other dietary components involved in producing these results.
Restricting protein intake in general, for instance, has detrimental effects on the body, mouse or human. Translating this research for real-world human use is more complicated than just reducing intake of high-protein foods, even though this is the simplest way to limit isoleucine intake.
The amino acid restriction level was constant in all experiments, and they acknowledge that more fine-tuning may be required for optimum effects across different mice 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," Lamming said.
"But narrowing these benefits down to a single amino acid gets us closer to understanding the biological processes and maybe potential interventions for humans, like an isoleucine-blocking drug."
The research was published in Cell Metabolism.
An earlier version of this article was published in November 2023.
That's nice :)
I remember your name from the Walter Reed National Military Medical Center posts, I think...
This is awesome... If you’re a mouse 😄
“LOL you are confusing deaths from predators versus longevity based on diet.”
????????
Mice and deer do not live long lives. Period. Most do not die from predators. However, most lions die at about 1/3 of their lifetime in captivity due to starvation and/or injuries from fighting or from damage while hunting.
“However, humans stand apart from all apes in some features of the gut proportions (Fig. 1). In humans, more than half (56%) of the total gut volume is found in the small intestine whereas all apes have by far the greatest total gut volume (>45%) in the colon (9,10). In addition, the overall size of the human gut in relation to body size is small in comparison to that of apes (9,10).
Hindgut dominance in apes suggests adaptation to a diet lower in quality than that consumed by humans, a diet containing considerable bulky plant material, such as insoluble fiber and seeds. In contrast, the proportions of the human gut, dominated as it is by the small intestine, the principal site of nutrient digestion and absorption, suggests adaptation to a high quality diet, one that is nutritionally dense and highly digestible relative to that of any wild ape “
https://www.sciencedirect.com/science/article/pii/S0022316623025518
Fire and the Brain: How Cooking Shaped Humans
“Compared to chimps, our nearest living relatives, and to australopithecines, the ancestors of our genus, Homo, humans have puny digestive systems. We have smaller teeth, weaker chewing muscles, and shorter gastrointestinal tracts. But we also have higher energy needs. Our bigger bodies require more calories to run. We travel farther than chimps as we go about our days (or at least we did, before modern societies invented the couch potato). And we have far bigger brains, about three times the volume of those of Australopithecus, and even more than that compared to chimps’. Big brains make a big difference, because brains use more energy than any other human organ—up to 20 percent of our bodies’ total energy use. So how do we get enough calories to support our energy-hungry bodies and lifestyles?”
https://www.amnh.org/explore/science-topics/microbiome-health/fire-cooking-human-evolution
That’s me. Those were great times!
I have read through #45, the last one at present, and I think I see the problem.
All posters so far are young.
Those of us who are older remember when coffee was poison. It would cause cancer, tumors in women’s breasts, ....
Butter would kill you. You must use a substitute.
Salt will kill you....
Beef will kill you....And eggs were as bad as the worst.
Now we are told that all are better for you than their substitutes.
The main lesson here is that there is an expert who has found something, but has no idea what.
My definition of a fool: One who knows everything but knows not what to do with what he knows.
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