Comment by _zagj | Hacker News Reader

Comment by _zagj | Hacker News Reader

> One of the eight biospherians was Roy Walford, a professor of pathology at the University of California, Los Angeles (ucla). Research by Walford and others had shown that restricting what animals ate could significantly lengthen their lives. The lifespans of nematode worms, fruit flies, rodents and dogs could be extended as much as 50% by laboratory protocols which gave them a diet with all the nutrients they needed in terms of minerals, vitamins and the like but fewer calories than were seen as normal.

Roy Walford died at age 79 of ALS, and there are studies showing both excessive exercise and low-calorie diets (drivers of calorie restriction) increase the risk of ALS, for example: https://www.thelancet.com/journals/lancet/article/PIIS0140-6... https://www.neurology.org/doi/10.1212/WNL.0000000000007861 https://www.thelancet.com/journals/ebiom/article/PIIS2352-39...

I can't believe people are still beating this drum. There's no evidence calorie restriction (beyond not being fat) actually significantly (ie more than a few years) extends human lifespan, let alone can consistently get you to 100 (or even 120, like Walford speculated). And if it did work, we'd probably know already just by looking at existing centenarian populations. And even the best animal studies (where, unlike 99% of the garbage mouse studies, the control group isn't allowed to eat itself into obesity) don't paint an impressive picture: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3832985/

> Our data indicate that under our laboratory conditions, CR does not improve mean survival in rhesus compared to CON monkeys despite clear improvements in overall health and function. Our finding contrasts with previous reports5, 19 and suggests that study design, husbandry, and diet composition are important factors for the life-prolonging effect of CR in a long-lived NHP, similar to what has been shown in rodent studies40–42. It will be valuable to continue to compare findings from on-going monkey CR studies to dissect mechanisms behind the improvement in health that occurred with and without significant effects on survival.

People like to believe in simple solutions for complex systems.

It also becomes easier to believe if you have to sacrifice something, do something hard..

Like eating less :)

If the solution was easy, then we wouldn't be so gullible, we'd have a much harder time believing it works.

> if it did work, we'd probably know already just by looking at existing centenarian populations.

This is a key point. Lots of people follow fasting type diets for cultural/religious reasons. Those groups are not over represented in existing centenarian populations.

Circumstantial evidences does not prove an effect, but if the effect is real then you would expect to see lots of circumstantial evidence that is compatible with the effect. Right now there’s nothing to even suggest that calorie restriction increases lifespan in humans.

The two I know the most, muslims and indians, seem not to follow "fasting type diet". Instead, they eat an enormous amount of fat, grow curry bellies, and look just as unhealthy as the scummiest american atheist...

However, where I live in Hong Kong, they eat a lot of fish, vegetable and low amount of trash food, and live very old. But they're also very rich in general so hard to be sure of the cause.

What culture/religion were you thinking of ?

Anecdotal. You are right about Indians being obese but it’s not because of the reasons you cited I think. Typical Indian diet now a days is extremely carb and sugar rich. Both of which contribute to the obesity.

Ghee on the other hand is expensive and is accessible to a tiny fraction of the population.

Check out that bluezone show on Netflix. https://www.netflix.com/title/81214929

The blue zone stuff has been debunked. It’s caused by poor birth records and pension fraud.

> In the United States supercentenarian status is predicted by the absence of vital registration. In the UK, Italy, Japan, and France remarkable longevity is instead predicted by regional poverty, old-age poverty, material deprivation, low incomes, high crime rates, a remote region of birth, worse health, and fewer 90+ year old people. In addition, supercentenarian birthdates are concentrated on the first of the month and days divisible by five

https://www.biorxiv.org/content/10.1101/704080v2.abstract

To add to your point, even if CR is proven to be beneficial, it would be very difficult for the majority of people to get CR right. More likely they'll end up restricting too much in the short/medium term, feel weak w/ no energy during this period, and will start to compensate by overeating later. Rinse and repeat.

It's such a delicate balance to maintain that without significant investment into monitoring, you're better off just consuming substantial amounts of complete protein and proper omega fat ratios + complex carbs. No need to overcomplicate things for the greater population.

> you're better off just consuming substantial amounts of complete protein

Except restriction of essential amino acids, as well as the total amount of protein, was consistently shown to improve health markers and longevity in many animal models, as well as in human epidemiological studies. It's not even news, the first evidence for methionine restriction in rodents dates to the early 90s.

I can't figure out what motivates some people to go online and assert their baseless suggestions with so much authority.

https://www.cell.com/article/S1043-2760(14)00127-1/fulltext

https://www.thelancet.com/journals/ebiom/article/PIIS2352-39...

https://nyaspubs.onlinelibrary.wiley.com/doi/abs/10.1111/nya...

https://www.cell.com/cell-metabolism/pdf/S1550-4131(23)00374...

Valid point about methionine restriction. I didn't mean to come across as making authoritative claims. I am simply cautioning people against jumping into dietary changes that would cause them more harm than good.

First things first, different groups of humans have different protein requirements (pregnant women, elderly, athletes, sedentary non-active adults etc) so generalizations in nutrition science are always dangerous.

Secondly, the studies you cited have been experimental on yeast and mice, but observational and correlational with humans - nothing conclusive about how a practical reduction in methionine and leucine in the real world for real humans would work, and how it would affect them long term. Those are two completely different scenarios, with the former being highly controlled studies of non-human species.

Thirdly, even if methionine reduction did positively affect lifespan/healthspan, the reality is that most people are simply not equipped to take on such a dietary change, leading to more harm done than good.

The reality is that, yes, many animal foods contain much more methionine than plant based. However, you also have to consider that if regular people tried to switch to plant-based (aside from lacking general education about plant-based diets), in order for them to consume sufficient amounts of protein from plants, they'd end up consuming a lot more calories (not only fibre but other simpler carbs) due to the higher calorie-to-protein ratio. This, especially if they don't live very active lives, would contribute to weight gain, all the while them thinking they're being healthier by being plant-based.

I understand that these are promising studies that have been around for a while, and I was a vegetarian for 5 years before switching back to omnivore due to becoming more disillusioned by the vegetarian diet, especially as I was trying to build muscle while on veggie+fasting, and failing.

But context matters, real world conditions matter.

Correlational/observational studies don't mean shit because they cannot possibly account for the diverse lifestyle practices of the participants living in the real world, try as they might.

Hence why I'm advocating for people to simply consume more protein, because, even though there might be benefits to restricting certain AAs, a lot of other implications to this dietary change might be overlooked, causing more harm to the health long term.

Let me know if I'm missing something crucial.

> nothing conclusive

It's true that conclusive lifelong human trials with appropriate controls are not available; but neither will they be, they're impractical.

The mechanistic basis for the health benefits of protein restriction is established to be conserved across species; they key aspects are mTor suppression, reduced IGF-1 levels and a shift from anabolic hypertrophy to catabolic autophagy.

This now famous study [1] showed that people in a large cohort who shifted to plant foods did manage to achieve lower mortality rates, perhaps challenging your assumption about the ability of the "regular person" to plan an effective diet that restricts protein.

In contrast to your experience, I am obtaining all micronutrients on a plant-based, whole foods diet, at under 1.5kcal/day; I drink one pea protein shake, for a total of 1.4 * bw. I'm happy with this, it's a form of "dietary restriction with optimal nutrition", but I'm not looking to increase muscle mass, because anabolic hypertrophy is detrimental to my longevity goals. I do exercise regularly and strength continues to increase, albeit modestly; this is consistent with a recent human trial that showed dietary restriction can lead to loss of muscle mass, yet without loss of strength.

[1] https://pubmed.ncbi.nlm.nih.gov/27479196/

Thanks for elaborating. I hope you're right, and after I'm finished with hypertrophy I'll try to tip the balance more in the direction of plant-based again. Cheers.

Anecdote:

My grandma is 92 (will be 93 in February), has always eaten a lot and never did any exercises except walking on the street. She used to be a school teacher and walked to work.

I don't know how many calories she takes, but always eats until full Here's an example of what a typical breakfast looks like:

- 2 eggs fried with butter - 2 breads with butter and cheese - couscous - cooked bananas - coffee with milk and sugar

She's somewhat above weight, but otherwise seems pretty OK. Has some dementia, but nothing out of ordinary for a 92

OTOH, my grandma is a bit older and has eaten oatmeal for breakfast for the last 50+ years. All that we can establish from these anecdotes is that neither fried eggs nor oatmeal will definitely kill you before you reach 90.

This tells you absolutely nothing, because you include no quantities nor any other meals.

I could literally eat this every day of my life and be either obese or underweight.

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