Eating Less Can Lead To a Longer Life: Massive Study in Mice Shows Why (nature.com) 25
Cutting calorie intake can lead to a leaner body -- and a longer life, an effect often chalked up to the weight loss and metabolic changes caused by consuming less food. Now, one of the biggest studies of dietary restrictions ever conducted in laboratory animals challenges the conventional wisdom about how dietary restriction boosts longevity. From a report: The study, involving nearly 1,000 mice fed low-calorie diets or subjected to regular bouts of fasting, found that such regimens do indeed cause weight loss and related metabolic changes. But other factors -- including immune health, genetics and physiological indicators of resiliency -- seem to better explain the link between cutting calories and increased lifespan. "The metabolic changes are important," says Gary Churchill, a mouse geneticist at the Jackson Laboratory in Bar Harbor, Maine, who co-led the study. "But they don't lead to lifespan extension."
To outside investigators, the results drive home the intricate and individualized nature of the body's reaction to caloric restriction. "It's revelatory about the complexity of this intervention," says James Nelson, a biogerontologist at the University of Texas Health Science Center in San Antonio. The study was published today in Nature by Churchill and his co-authors, including scientists at Calico Life Sciences in South San Francisco, California, the anti-ageing focused biotech company that funded the study. Scientists have long known that caloric restriction, a regimen of long-term limits on food intake, lengthens lifespan in laboratory animals. Some studies have shown that intermittent fasting, which involves short bouts of food deprivation, can also increase longevity.
To outside investigators, the results drive home the intricate and individualized nature of the body's reaction to caloric restriction. "It's revelatory about the complexity of this intervention," says James Nelson, a biogerontologist at the University of Texas Health Science Center in San Antonio. The study was published today in Nature by Churchill and his co-authors, including scientists at Calico Life Sciences in South San Francisco, California, the anti-ageing focused biotech company that funded the study. Scientists have long known that caloric restriction, a regimen of long-term limits on food intake, lengthens lifespan in laboratory animals. Some studies have shown that intermittent fasting, which involves short bouts of food deprivation, can also increase longevity.
Sp you become slow? (Score:2)
This works because calorie restriction "dial's down metabolic rates — a short-term effect thought to signal longer-term benefits for lifespan".
If your body's metabolism slows, everything (including the aging process) slows with it.
But surely it's more fun to "live fast, die young"?
Well that was my plan... but here I am in the second year of my eight decade on the planet and still going. Clearly I need to revise what I'm doing.
Re:Sp you become slow? (Score:5, Informative)
Take the time to TRFS
"The metabolic changes are important," says Gary Churchill, a mouse geneticist at the Jackson Laboratory in Bar Harbor, Maine, who co-led the study. "But they don't lead to lifespan extension."
FTA
However, the effects of dietary restriction on metabolism and lifespan didn’t always change in lockstep. To the authors’ surprise, the mice that lost the most weight on a calorie-limited diet tended to die younger than did animals that lost relatively modest amounts.
This suggests that processes beyond simple metabolic regulation drive how the body responds to limited-calorie regimes. What mattered most for lengthening lifespan were traits related to immune health and red-blood-cell function. Also key was overall resilience, presumably encoded in the animals’ genes, to the stress of reduced food intake.
“The intervention is a stressor,” Churchill explains. The most-resilient animals lost the least weight, maintained immune function and lived longer.
Summary, don't be fat, and fast on occasion, but don't go and starve yourself
Enjoyment (Score:3)
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The ones who weren't balls of fat whose joints weren't destroyed from the excess weight and as a result were able to move around with ease?
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Re:Enjoyment (Score:5, Funny)
The mice in the fentanyl addiction study
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I never claimed it would lead to a long life, just one saturated in endorphins
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Re:Enjoyment (Score:5, Interesting)
I started intermittent fasting a few years ago. My motivation at the time was to lose weight. A friend of mine told me that she had gradually gotten herself into eating just once per day, and it sounded crazy to me. But to start I was just skipping breakfast for the most part and making sure that I don't eat late night snacks. So the "feeding window" was around 5 or 6 hours or so.
And then I tried just eating once per day to see how I'd feel... and I was suprised that I wasn't dying of hunger pangs.
A few years later and now I sometimes do prolonged fasts where I don't eat for up to 5 full days (120 hours). I don't do this often, but I have and I can and I know how I feel when I do.
I learned a few things along the way:
1. Hunger comes in waves. It's caused by the release of a hormone called ghrelin, and your body seems to release it around the times of day that you are accustomed to eating. So I always feel hungry at the same times during the day without fail. For me it's first thing in the morning, noon, 5pm and 9pm ... even if I'm not fasting at all I and have eating throughout the day I will always always always feel hungry at those times. It's like clockwork.
2. If you ignore that cyclic hunger, it goes away on its own. We assume that if we get hungry and don't eat that we'll just keep getting hungrier and hungrier but that's not what happens. In fact, I find that the less I eat, the more I want to eat. It's really strange that way.
3. I'm becoming convinced that eating is not even what makes that cyclic hunger go away. I mean, if time itself will cause it to pass.. and eating takes time.. and it takes time after you've eaten for the hunger to go away ... did the eating even do anything directly as far as the ghrelin hormone goes? Maybe, but I'm starting to think that maybe the two are actually not that correlated.
4. When I fast .. if I start to experience light-headedness, it is NOT low blood sugar but an electrolyte deficiency. Having some salt (and I've since bought electrolyte supplements which are just sodium, magnesium and potassium) makes it go away instantly without eating a single calorie.
Now, I do love food .. and I am a stress eater. But I feel the happiest when my diet, sleep and exercise is on point. Diet here doesn't necessarily mean that I'm actively fasting, it really just means that I'm not eating foods that are going to trigger a major insulin spike and cause me to feel tired afterwards and to start putting on weight. Sleep and exercise are the other two key factors. I'm not a gym rat by any means (I work out at home and some mornings I need to really force myself to) but I find that a daily exercise regimen is the best thing I've ever introduced for stress management. And if I don't get enough sleep then diet and exercise go out the window and I'm grumpy. When all 3 have been tended to I feel happiest.
The occasional slice of cheesecake or alcoholic cocktail makes me feel happy too but only when it's occasional. Do it every day and the fatigue, depression, brain fog and low energy all starts to creep back.
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In fact, I find that the less I eat, the more I want to eat.
Self-replying to fix a typo for clarification. I mean to write "the less I eat, the LESS I want to eat."
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To be fair, hunger is a great motivator for physical activities in environments where food is not readily available.
I remember watching a documentary on New Guinea where even the village elders were sporting six-packs and could likely have outperformed most westerners of similar age.
Most modern humans have circumvented this with the ready availability of food, which only requires a short drive to the market or drive through (not to mention online ordering)
People who run zoos, have found that their charges a
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Re: Enjoyment (Score:2)
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Hunger comes in waves.
Yes.
No, I get hunger pangs every few hours.
No, the pangs become physical pain.
A few months of that was all I could endure. But it taught me to eat less, eat slower and eat less meat. Many people want to move away from the high-carb. diet that became standard in the 1970s/1980s but a mostly carnivore/paleolithic diet is too many calories for me. Plus, my body seems to have difficulty absorbing calories from many wheat-based foods (gluten intolerance?): That allows me to eat more, avoid the physical pain
Update TFS (Score:3, Insightful)
Why does TFS skip the conclusion of the study?
The existing position, that fasting increases longevity, was overturned. Instead new factors: immune health, genetics, resilience, better explain the longevity. So how do the new factors explain the correlation between fasting and longevity? You skipped the one point in all this that was really interesting.
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I don't get the conclusion anyway; it really seems to say that caloric restriction does work, but results will vary based on your genetics.
We are no closer to understanding the mechanism, we just know it's not universally uniform in results when triggered.
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Caloric restriction works up to a point, but the mice who lost the most weight died young, and the ones who lived longest lost the least amount of weight
I think that the most important thing they identified is "immune health and red-blood-cell function" because your immune system can really mess you up if it turns against you, and red blood cells are a must-have so anything that prevents them from generating properly will end your life in a rapid manner
For myself, I have added three things to my regimen, re [nih.gov]
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Another interesting mouse study relates to Hardiness, and is not dependent on genetic advantage
As a matter of fact, most mice in studies are fairly similar genetically due to intentional inbreeding, but epigenetic studies have shown the baby mice that are nurtured have better Hardiness because the serotonin produced during nurturing protects their folded DNA, resulting in less damage at the folded "knees" of the DNA
While we cannot go back and be re-nurtured, we can provide for our own young and give them ad
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Caloric restriction works up to a point, but the mice who lost the most weight died young, and the ones who lived longest lost the least amount of weight
From the article:
40% is a significant calorie reduction.
You'll live longer (Score:3)
but you will like it less!
Next, castration (Score:2)
Castration is claimed to do this also. Is it because energy is no longer spent on masturbation and looking for sex? Or because, removing the energy boost of testosterone means eunuchs move slower and rest more (like 50-something males): Doing less damage to muscles and recuperating more.