Lifestyle and environmental factors affect health and ageing more than our genes | Hacker News Reader

Lifestyle and environmental factors affect health and ageing more than our genes

ox.ac.uk

55 pointsgnabgib26 comments

I believe/understand it is mostly tied to reproduction and protection and development of offspring.

Dogs (and many other animals) begin reproducing at a much younger age. Their genetics and genetic development evolved to support releasing a number of offspring to continue the species, but beyond that, the biological system had no longer value for the animal, and therefore genetics which enhanced longevity did not promote into the next generation.

People rear children later, and when those children are growing, the human still plays a very active role in the development and maturity of those children. The genes which promoted longer life where therefore selected out as the children who were not reared with parents in reaching late 30s had a lower chance of survival.

In addition, humans have a strong drive to live. Dogs, as they reach the end of their life, seem to be quite happy to find a nice place to lie down and die. They have no concept of "not dying". Not that they won't protect themselves, but they have no idea of medicine, of health, these are not concepts many other species can understand, and even if they could, there is not much they could do for them.

With royalty and family, younger generations cared for the older, which increased lifespan beyond the generally accepted declining years.

For example (I work in sleep), sleep begins degrading in our 30s, and this degradation is linked to all markers of aging and health. Our immune system weakens, our metabolic and cardiovascular systems decline, etc etc. Potentially there was/is some evolutionary selection here as well where the children who cared for their elderly were also more likely to survive longer, but I think that is a weak link.

I'm not refuting the OP, but at one point genetics got us so far, and then lifestyle and environmental factors are now taking over.

(edit) I originally posted this as a response the question about dog lifespan, but then realized it probably stands on it's own as a comment.

How come almost all humans live longer than dogs then. Dogs don't smoke and they are very physically active, yet they generally die before the age of 20*.

The article is a based on a over generalisation from study results that are not applicable in the way that the article claims.

*The dog metaphor is sort of a joke, but it is true for the human case to, due to the fact that you cant factor out the genetic "effect" on behaviour.... ie. behaviour and genes are too intertwined to separate from each other. Smokers smoke in part cause they have the genes that make them more likely to smoke (or exercise, or overeat, or do whatever; just pick any example that is unhealthy).

I think it's fair to assume that we're not talking about the genetics of other species here.

Genetics does not draw neat lines.

In the same way that there is not a neat line where land meets sea, yet any reasonable person can distinguish the difference between the two and understand that they are not the same.

Dog aging is irrelevant. It's well-documented that dogs have a faster biological aging process due at least in part to the telomere caps on chromosomes which protect the DNA. Dogs lose these caps at a rate around ten times the human rate.

https://www.sciencedirect.com/science/article/pii/S221112471...

I remember seeing discourse recently saying telomere shortening is a side effect more than a cause of aging as a function and happens as a function of DNA damage. Important to consider

Sure, but it also has some correlation to body size. Larger animals generally live longer.

Then why do large-breed dogs die around 8 years of age when small-breed dogs can live to twice that easy?

It's pretty obvious that it only applies to the same specie. If you live 100m from a highway, breath brake pad and tire particules all day, smoke 2 packs of cigs a day and drink 1L of vodka every morning you will statistically live a shorter life than your genetic twin who lives in an unpolluted rural area who eat pesticide free food and don't smoke/drink

That's all there is to it, some people smoke and live long, some people don't smoke and die young, but statistically no one smokes a lot and live longer as a result.

Just look at the leading causes of mortality, they're mostly behavior or environment related

The article is talking about genetic variation within humans. The title omits this, making it an incorrect summary of the article (and it’s unclear what it even means)

i understand "affected by genes" to mean exactly "genetic variation". what else could it mean?

People might expect “affected by genes” to be an objective fact not related to the current variation of genes we actually have. For example, let’s say there’s a gene that reduces lifespan by 1 year that half of people have. If this gene spread so that in the future everyone had the gene, lifespan would suddenly be “less affected by genes” than before. (Because variation in this gene no longer exists, genetic variation will have less effect on lifespan.) But of course, lifespan is still being affected by this gene.

I'd think of it in terms of a sort of species normative lifespan and indicators of aging. Let's say it's 80 effective years. What this study is saying that factors other than genes have much more more influence on whether you make it to (or even past) the normative lifespan/age. Not that the length of the generalized normative lifespan isn't a product of genes, or that individuals who appear as severe outliers aren't doing so because of genetic factors. But that the largest factor impacting premature expression of normative age or pre-normal-age death aren't genetically driven at the population level.

I would note, however, that this result is going to be extremely influenced by the society being studied. If famine is widespread, then many genetic factors won't matter. Similar for war, etc. (And this is probably partially why socioeconomic factors have a big influence.)

The Oxford study is big and I am sure well done, but it boils down to what I hope we all knew—human health and healthspan are both mainly about non-genetic factors. Avoid pestilence, famines, wars, and crazy leaders; eat right, exercise, do not smoke. Have a good social network at all ages. Stay active.

The estimate of the magnitude of genetics effects in this study is “silly low”, roughly by an order of magnitude. (Notice the hedging in the PR piece.)

The heritability of a trait is a function of environmental stability and quality. In a stable environment—Sweden or Iceland from 1900 to 2000—-heritability of lifespan is still low; about 15 to 25%. But that is way different than 2%. Claiming 2% is more of a socio-political statement: to focus on what we can influence ourselves.

Re telomere length. I wish it were that simple. Telomere length is not the main cause of aging in mammals. Read the title if the paper that you cite: “correlates with”! My presbyopia correlates beautifully with my age but did not cause me to age.

I would not even rank telomere length among the top ten (the putative “Hallmarks of Aging”). But it is a great story which makes good headline fodder.

I think the comment about dogs is really just highlighting the wide range of differences in maximum lifespan among species.

This indicates that DNA variants indirectly or directly modulate the baseline tempo of aging between a short lived mammal (less than a year) to species like us that live 100 years. There is really no doubt about this.

And of course DNA variants do the same thing but over a much more modest range within a sexually reproducing species. Some mice make it to 500 days, some make it to 1000 days in exactly the same environment. Reduce environmental variance sufficiently and heritability begins to get up to 40%. Out in the wild here almost no mouse dies of natural cause heritability should approach zero.

Aging is highly polygenic. There will be 100s of DNA variants and de novo mutations contributing to aging per se and to disease risks. And many processes.

Incidentally I was just doing some digging through https://en.wikipedia.org/wiki/List_of_the_verified_oldest_pe... recently, and it seems most if not all of them didn't have any particularly healthy lifestyles, so I suspect it is largely genetic.

There are some surprising notes in https://en.wikipedia.org/wiki/Jeanne_Calment#Health_and_life... such as:

Calment continued smoking in her elderly years until she was 117

And https://en.wikipedia.org/wiki/Christian_Mortensen :

Mortensen enjoyed cigars in moderation and drank lots of water

Also some stats on the countries represented in the above list:

    US 38F 27M 65T
    Japan 23F 19M 42T
    France 7F 4M 11T
    UK 5F 5M 10T
    Canada 3F 2M 5T

I am not claiming to be an expert, but as i understand it, there have been instances where someone looses all their paperwork and is reissued after being asked how old they are. A shrewd individual may say an age that is greater than their actual age, in order to claim a state pension earlier than they would otherwise be entitled to. It has been said that this is the cause of the famous “blue zones” in Japan and Spain.

In the case of Jeanne Calment, there is suspicion that her daughter took her place in order to claim her pension.

It is completely unproven despite a thorough investigation, but reaching the age of 122 is so unlikely that some people think that fraud is still the most likely explanation.

I'm pretty surprised they found *correlations between mortality and supplementation. I wonder how they can separate that from socioeconomic status.

Also, I understand why they tested multi-vitamins and fish oil, but I wonder why they asked about glucosamine?

> Also, I understand why they tested multi-vitamins and fish oil,

I don’t see that in the linked article or in the paper. The words vitamin and fish don’t appear anywhere in the paper either. I didn’t see supplement use in the tables.

Where are you seeing this?

In the last 3 lines on the right-side of the graphic.

Fig. 2: Environmental architecture of mortality in the UKB.

https://www.nature.com/articles/s41591-024-03483-9/figures/2

Castaneda's Don Juan says that life is more about what we avoid doing than what we do.

Like, we should not repeatedly go to the shoe store to play with their new x-ray foot measuring device, or use those new glow-in-the-dark radium cosmetics.

You mean clean living pays off?

Say it isn't so . . .

I just need a son who's blood I can siphon

Don't genetics make it more or less likely that you'll live a healthy lifestyle? Say for example if you have depression.

influence ageing and risk of premature death 30-80 years later;

How relevant this study actually is?

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