Animal protein intake is inversely associated with mortality in older adults | Hacker News Reader

Animal protein intake is inversely associated with mortality in older adults

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79 pointsrsj_hn86 comments

FTA: plant protein is also associated with lower mortality. So... more protein is just better?

I wonder if strength is part of the explanation. We know that there's a strong association between strength and mortality, so maybe a higher protein diet just helps maintain more strength as people age. https://pubmed.ncbi.nlm.nih.gov/18595904/

Malnutrition with seniors is a gateway to many other medical issues. Current guidelines teach seniors to eat the protein and high calorie foods first (even dessert first) before hitting the vegetables. This result is consistent with the current body of knowledge.

From what I recall from seeing mortality curves vs BMI, away from the expected minimum the curve rises much faster for low BMI than high BMI.

Makes one think. In a high-self-control-valuing society, "heavy" is perhaps seen as lacking virtue, but in many societies "skinny" is perhaps seen as lacking utility.

They also tested plant protein (read further down):

> Plant protein intake showed no association with any of the mortality outcomes

So, for whatever reason, it was only animal protein in this study. Previous studies in younger populations have shown benefits of plant protein, though.

Maybe you misread the article. Plant protein is inversely correlated with mortality in middle-aged adults. They focused entirely on patients with a mean age of 75 years.

regarding the group they studied "Plant protein intake showed no association with any of the mortality outcomes"

One interesting remark in one of Joe Rogan's interviews with a former vegetarian, was somewhat like the following ...

He stated most animals can be eaten by humans, but most plants cannot. Because plants cannot move, plants need to have some innate defences to prevent being killed before being able to reproduce and as such many plants are poisonous. Humans apparently have evolved to be able to disregards some poisons in some plants.

Also, in this interview the former vegetarian stated that if humans were to eat pretty much all of the meat of the animal (including liver, heart) they would get most of the vitamins required to stay in good health.

Now I don't know exactly which person Joe interviewed. Might have been Paul Saladino.

I love that the fact that the interviewee was a vegetarian makes them an expert!

Is a plant protein diet associated with lower mortality in the Inuit people?

Protein (well amino acids) is used by the body to repair tissue. Amino acids are more available in animal proteins than in plants. There are scores [1] for ranking protein availability, and the top ones are animal protein (the humble egg ranks very high).

You can get the same proteins from plant sources but you have to eat a lot more of it (which can be difficult to do -- not everyone can eat a lot even if it's fun foods) and also supplement the limiting amino acids. I believe most diets fall short of the recommended amount.

[1] https://en.wikipedia.org/wiki/Protein_quality#Protein_source...

A long long time ago I read a forum post that evaluated mixing various types of plant based protein powders at various ratios to achieve a high PDCAAS score. The only things I can recall are that a 70/30 mix of pea protein and rice protein gave you above a 1.0 score, and mixing hemp protein in with anything made the score worse. You can conveniently buy cheap pea protein powder and rice protein powder in 7 and 3 lb jugs.

This was specifically about protein powder, but I think you could achieve similar results in your diet by combining different plant based foods in a meal.

You can definitely get the right proportions by mixing, though you might have to eat (in this case drink) a lot more plant protein (in terms of volume) to get the comparable amount in g vis-a-vis animal protein.

"Plant protein intake showed no association with any of the mortality outcomes, but an interaction with baseline hypertension was found for all-cause and cardiovascular mortality (p<0.05)."

From what I have read it is actually the completeness of meat protein that is the problem and the interaction certain amino acids have with mTOR.

Plant based diet basically starves mTOR better from the aminos that plant protein lacks.

I basically eat a vegan diet but cheat on the weekends eating meat because I love meat.

The real problem with veganism is that it is so hard to separate biology from the "food religion" of veganism. The idea of being vegan during the week but eating a hot dog on the weekend is literally blasphemous.

That's because you're using the terms incorrectly. I wouldn't say that I'm pacifist during the week, then pick fights with the homeless on the weekends. It doesn't make sense because pacifism, like veganism, describes a philosophical viewpoint. And you can't willingly change your beliefs just on the weekends.

You want to describe your diet? Then just say you don't eat meat during the week.

Interesting, but as the authors state: “Further studies are needed to provide recommendations on dietary protein intake for older adults.”

That is an understatement. There is no causality here; just correlation and many potential confounders—environmental, social, genetic.

To resolve the role of macro- or micro-nutrients in health and lifespan requires either controlled studies of highly diverse but replicable rodent cohorts (e.g. Roy S. et al 2021; https://www.biorxiv.org/content/10.1101/776559v3)

or much more expensive long term randomized clinical trials if large human cohorts (e.g., the NIH Women’s Health Initiative and some of the Framingham studies).

Studies like this one are intriguing and fun, but shallow in the sense that they cannot provide core insight into causality.

I can't extract anything meaningful from this comment. It seems you are repeating a lot of "go to" sayings about how science should be done in a hand wavy way without understanding the why, then using that to dismiss the results.

For example you say

>There is no causality here; just correlation and many potential cofounders...

what does this specifically mean? When A and B are correlated to statistical significance, either A causes B, B causes A, or something else is causing both A and B. So, how could the future act of living longer be causing people to eat more protein? Or, what possible things could be causing people to eat more animal protein and live longer at the same time? I can't think of anything plausible.

It is fair to say that this study is very good evidence, as good as anything can be, that animal protein is important for longevity.

Another comment in this thread points out that a huge confounder could be income. Indeed, as @robwwilliams points out, there could be many potential confounders, including genetics and environment. All that means is that, if drilled into, researchers might find that X (where X is whatever confounder you can think of) might be a better predictor of mortality than protein intake.

It seems to me that the parent comment doesn't aim to "hand wave away" this paper, but instead to suggest that it is a singular datum whose findings should be tested by larger, more in-depth, research (which could test for a whole set of confounding variables that might come to mind). The authors of the original study state the same thing right in their abstract!

I'm not sure why you think that point is not meaningful. IMO, that is exactly how science should be done ---interesting correlations should be stress-tested. If the findings hold up, then we can be especially confident in whatever choices we make. If the findings don't hold up, we then have new avenues to research.

> Or, what possible things could be causing people to eat more animal protein and live longer at the same time? I can't think of anything plausible.

That's a failure of imagination. A plausible example might be socioeconomic status (rich people live longer and also eat more expensive foods such as meat).

An environmental factor that reduces longevity and alters your sense of smell or taste in a way that affects your diet is semi-plausible (heavy metal poisoning such as cadmium can cause anosmia, which will affect food preferences), smaller but more widespread effects are possible.

Arguably we're already the beneficiaries/victims of mutations that make cooked food (that is more easily ingested and digested) taste better, but also make food subjected to combustion processes like smoking, searing, roasting, etc. (which can produce various carcinogenic polycyclic aromatic hydrocarbons as a side effect) smell and taste good.

A fanciful hypothesis would therefore be a mutation that directly increases longevity and also happens to make meat taste better (or vegetables taste worse, like they do to supertasters) and so affect dietary preferences.

Thanks to McDonald's, KFC et al at least the first part can safely be dismissed? Meat is among the cheapest ways to feed yourself if you disregard quality. But I don't think the study mentions they specifically only considered people eating high quality meat.

The study was done in the EU on older adults.. They are very unlikely to eat McDonalds and meat is not as subsidized as in the US. This study might return opposite results in the US, or even elsewhere within the EU like Germany, where obesity is closer to the US.

Also their reference to animal protein might mean they are on average moving higher fat meat/lower quality meat eaters toward the lower animal protein intake than average if this demographic eats a lot of meat but of different quality.

I don't have access to the study itself to check, but it seems like a huge confounder is income. Meat is more expensive on a per calorie basis than plants and poverty is associated increased mortality for many reasons.

This goes backwards to that. Higher meat intake is associated with higher mortality

I think you have it backwards. It says meat intake is inversely correlated to all-cause mortality.

No yeah you're correct, double negative slipped me up haha

20 years of checkins on what people eat, has anyone gotten the PDF and seen how they actually do this follow up?

Most food diaries are basically bullshit, so I'm curious what they had to do with their data to make it actually useful.

When I saw that the method involved questionnaires I took this with a kilo of salt. Considering that people forget what they had or generalize pretty badly this kind of method is only as good as the individuals and what they report accurately.

'inversely associated' means people who ate more of it lived longer or the opposite? I'm hella confused

Double negatives are hard to read but yeah more meat less chance of death.

woohoooo more steak and burgers for me!

Isn't there like a 100% chance of death?

I mean only 93% of humans have died so who knows for certain....

https://www.prb.org/articles/how-many-people-have-ever-lived...

> Isn't there like a 100% chance of death?

Not, just 99.99999%.

Clonal cell lines are basically immortal.

(And the chance of death at a given age is not 100% necessarily)

"inverse association" is a standard way of saying that when X goes up or down, Y does the opposite.

I have never seen mortality used to mean lifespan.

I assume it is a clickbait title technique intentionally misusing words to pique interest.

It's not being used to mean lifespan. It's being used to mean death.

Mortality is often used when talking about the likelihood of dying.

A lot of other studies with better research say the opposite.

My take:

The amino acid profile in animal vs. plant proteins is the reason, with excess Methionine being the culprit. It's needed in greater quantities during your growth phase of life, not as much as you get older

Methionine increase homocysteine levels, leading to greater heart disease, and it's been implicated in cancer too (esp tumor growth)

Something called "recombinant Methioninase" is making the rounds in cancer research actually -- it lowers Methionine levels.

For the curious, my medline saved search

https://pubmed.ncbi.nlm.nih.gov/?term=%22l+methionine+gamma+...

My girlfriend is studying aging in her masters and I read some papers with her that said that more protein help your body grow muscle mass, but not repair damage in cells, and lower protein intake allows your cells to fagocite, destroying damaged cells, leading to better health overall and more longevity.

This is completely opposite from what this paper is saying.

Maybe I can help clear something up for once in these comments! My focus is on substance abuse and not aging, but I've been following the literature and what has been gaining prominence is the "cold wet hungry" hypothesis. That is to say, our ancestors were often cold, wet, and hungry, and our body evolved defenses to deal with those endemic conditions. Though we live past infancy in much larger numbers, our resilience to aging is decreased by sedentary lifestyles and high carbohydrate, high protein, and high fat diets.

If you're meeting your protein requirements, things like intermittent fasting can help your body better regulate inflammation and thus aging (which can better be thought of as disregulated inflammation)

Big meat lobby fighting against chik'n. ;)

There are laws in 6 US states where there are penalties for criticizing meat agriculture, so-called "ag gag" laws, as Oprah found out in the 90's.

If you are worried about big meat than surely you acknowledge there is at least as big an agenda of shoving soy and bugs down people's throats. Democrats, UN, WEF, lots of NGOs all have thrown their weight hard behind it. What makes you think "science" against meat is any less pressured?

Yes, industry people who want to protect their income no matter the moral cost are interchangeable with non-profit entities.

I do not have access to the article so difficult to say but they do specify "community-dwelling" which I believe means they were in something like assisted living facilities.

This would make data collection on food intake much easier since the specific meals would be prepared by the facility and they must have records of which resident had which meal.

While these are super interesting headlines, I think the chances of some hidden driver affecting animal protein intake is very likely. E.g., it is not uncommon for geriatric individuals to be unable to consume specific foods or have doctors specifically restrict their diets due to heart disease, blood pressure, cholesterol or any number of other factors.

Without detailed analysis of confounding health factors, I would not read this as prescriptive. In fact, animal protein intake may be even be a trailing indicator.

This is just anecdotal but my grandfather is nearly 90 years old. He has been eating goat meat, chicken, fish and prawns at least 4 days a week his entire life. Although he raised his own goats and fish as a farmer. And he has eaten "organic" food most of his life. He is quite healthy. Whereas many vegetarian members of my family and close family have lots of health issues. Granted many of them are living in the cities and are dependant on processed foods, refined oils and fresh produce laden with chemicals. I know that there are a lot more variables affecting the outcome not just eating animal protein. But I don't doubt this study, although that's confirmation bias for me!

Survivorship bias may also be a factor

Does that really apply here? Seems to just be anecdotal as they suggested

We don't know. What do the grandchildren of the grandfather's siblings say about their grandparents?

How much does he eat? There is an inverse relationship between caloric intake and mortality; the less you eat, the longer you live. Also, keep in mind that animal protein is not necessarily meat, meat would be a subset of animal protein, which means this study does not remotely conclude that meat intake is inversely proportional to mortality.

Though some will claim otherwise and I envy them, it is not easy to eat vegetarian, so your anecdotal insinuation that vegetarianism is less healthy could be due to the fact that readily available options, if they exist, are vanishingly slim. For one, there seems to be meat or meat byproduct in everything. No major restaurant chain caters to vegetarian diets, unless you count Subway with all the exposed deli meat and preps touching meat, it can kill appetites, and I wouldn't call Taco Bell's bean burrito catering to the vegetarian diet. Vegetarian restaurants are incredibly rare, and I don't understand why. Most restaurants will have a single dish that is vegetarian on a menu that is 4-5 oversized pages long. And if you're in the sticks, forget it everything has meat, and often it is causing trouble to ask the meat be left out.

And when you do find a vegetarian restaurant, the entrees are often exotic and bizarre (even if delicious, they just don't need to be that complicated or expensive). I don't get why there isn't a restaurant that prepares and serves everything Americana except the gratuitously included meat in every single entree. If I had any startup money, I'd open a chain of vegetarian fast food restaurants that serves all vegetarian entrees, with plenty of calories and nailing all the nutrition metrics, but made only with familiar food resulting in familiar, non-intimidating dishes with prices compatible with those of any fast food place.

> If I had any startup money, I'd open a chain of vegetarian fast food restaurants that serves all vegetarian entrees...

What kind of entrees are you thinking of? I notice more vegetarian and vegan restaurants coming up in the bay area atleast. But the prices seem a bit higher.

> What kind of entrees are you thinking of?

I'm not all that creative with food, grilled cheeses would be on the menu, as well as cucumber sandwiches, various fresh raw fruits (apples, pears, citruses, berries, melons, tropicals and exotics), all major forms of how a potato can be prepared, corn on the cob, actually any corn preparation, lot of breads and bakery items (ideally made fresh on site if practical), beans and rice dishes, and just rice and veggie dishes, and pasta dishes with various primavera sauces maybe served in a cup at the drive thru so could be eaten with one hand without utensils, probably would have to have a fryer, so any vegetable would be available fried (I know it's not good, but tastes ok, and can be vegetarian), salads salads salads, all the lettuces and cabbages and spinaches, vegetarian chili (did you know Chili's doesn't serve any vegetarian chili? I mean, come on), veggie tamales, fajitas, tacos, burritos, veggie Chinese dishes (apparently, not yet invented), veggie Japanese dishes, all the cheeses available on anything, maybe a few types of butter, also available on anything, and likely all the various ways to prepare eggs, definitely including fried egg sandwiches with tomato & mayo, but also sim egg preparations if preferred. Meatless breakfasts all day and all night. I can't stand tofu, but some people like it and it can be prepared to taste like anything, though I've had these great veggie burgers before that do not taste or look at all like burgers or meat, just a veggie formulation in a patty on a bun with tomato, lettuce, ketchup & mayo that tasted like what it was, and veggies taste really good, so I'd ban any and all meat flavoring and meat simulations. You can get meat taste anywhere else. Also, chick pea formulations, various ranges of humus (I made a humus once without tahini, and mixed in banana and used strawberry rather than pimento, and no one who tasted it could believe how amazing it was... gave away about 20 sandwiches that day). The thing that would be great about this restaurant is that I wouldn't have to make the food, pros would do it. Also, pretty sure there'd be a juicer somewhere... ever had real juice? It is a crime what passes for juice in a grocery store (I guess the orange juice is ok, little else). Also would have to serve all the gourmet coffees. And shakes, ice creams, frozen yogurts, sorbets and ices. And fresh nuts, all the nuts there are... would probably have a dedicated nut menu, but also available garnished on anything.

I honestly know nothing of the business, but I expect it would have to have reliable and just in time suppliers, and over time inventory would stabilize, reducing waste.

I think you have pretty good ideas. I have not seen a place that does all of those things but a little it here and there. Seen places that just do grilled cheese, or baked potatoes or just corn on the cob.

> veggie Chinese dishes (apparently, not yet invented)

There are all veggie Chinese restaurants around. This one I've tried it was okay but not top notch Chinese food.

https://www.veggieleehaywardca.com/

I've been thinking of trying this one myself.

https://instore.rawasf.com/?location=11ea381cde02ae71891d54a...

These guys have pretty good vegetarian bowls.

https://www.thehummusrepublic.com/

California has some decent restaurant options for vegetarians, more so than the rest of the US. I lived in Southern California a few times, and though I've never been, I would love a long sabbatical in Northern California. I kind of wish I lived at Skywalker Ranch (maybe not in the main digs, but a little cabin in the woods) and worked at Skywalker Sound, and I could get down to the Bay for the culinary vegetarian delights. I also wouldn't mind living in Cupertino and working for Apple at hq, though I'm not sure what I'd do. I believe most of their systems engineers are spread out thin across the country rather than concentrated at any Apple offices. Instead I contract around Tidewater VA, and it suits me, but for the deficit of restaurants with vegetarian dishes.

I don't think he is healthy just because of eating meat. He is healthy because of a number of factors.

1. He ate good quality food, that includes both meat and vegetables that he grew for consumption. 2. Farming is hard work so he physically quite fit. In fact even at this advanced age he still rides bike around. 3. Portion control: He never eats more than he needs. 4. He is quite stoic and usually doesn't give shit in the face of adversity.

It's important to eat a lot of vegetables along with meat. I don't think eating anything in excess is good for health.

>> Also, keep in mind that animal protein is not necessarily meat, meat would be a subset of animal protein..

Yes, I understand what animal protein means. I also understand that you're possibly a vegetarian. I was a vegetarian for 13 years but I'd to start eating meat again for personal reasons. I think I feel a lot healthier with a meat based diet. Also, I didn't insinuate that vegetarianism is less healthy. I only reported by observation in my family circle. Most of the people who're eating a pure vegetarian diet have serious ailments. And most people who grew up eating meat are comparatively healthier.

Although, in the current times I don't think it matters much. Most of the food produced are full of toxic shit. And it could be the reason for their ailments not just meat or vegetarian diet. Just to clarify, my family is in India. The quality of food has gone down drastically in the recent years.

I would recommend you pay very close attention to how you feel in the first three hours after eating, say, a nice sized filet minion. One day it just hit me that meat always kicks my ass. I used to love going to Outback for the steak. Then it occurred to me, every single time I ate meat, digesting it would exhaust me. I'd usually lose consciousness within an hour after eating, and it is ordinary to feel sleepy after eating, but I'm talking about an overwhelming, irresistible tiredness that lasted hours. I'd be out for 2-3 hours, and always woken by GI discomfort. Without fail, meat ultimately puts me on the toilet. Once I realized the result was always the same, quitting meat was an easy decision, yet being a vegetarian is hard (because this society makes it hard, not only to be a vegetarian, this society makes it hard to find anything but crap to eat).

> A prospective cohort study including 1,139 community-dwelling older adults (mean age 75 years, 56% women) living in Tuscany, Italy, followed for 20 years

Doesn’t seem like the type in d population that would have a usual vegetarian

It’s very complicated to eat plant based proteins properly. There’s so many “gotchas”, if you don’t get it right and keep eating that way for a long time you’ll do serious damage. Better to just eat good animals.

Not really? People across the planet have had predominantly or exclusively vegetarian (not necessarily vegan) diets since forever and have been perfectly healthy.

I think there are - might be misrembering - more credible studies that you can live on a diet of exclusively potatoes without ill effects aside from, well, that kind of diet itself.

I looked over the article and was expecting to see something on it like "Funded by [Tuscany's version of the Beef Producers Council]."

Another people, like the Inuit, exclusively carnivorous diet and and been perfectly healthy.

There is no diet for everyone. All diets are fundamentally dictated by our genetics.

As people age they tend to eat less, so intuitively it makes sense to me that people that eat more meat live longer due to meat having pretty good nutrient profile.

Everyone seems to be making this assumption, but animal protein is not necessarily meat, thus, the study is not concluding meat intake is inveresly proportional to mortality. Also, those that eat the least of anything live the longest. And regardless if meat has a good nutrition profile (granted, there's protein, iron, zinc and vitamin B12), eating meat increases risk of premature death. Consuming two servings or more a week of red or processed meats is associated with an increased risk of heart disease and mortality. IOW even consuming something nutritious can be very unhealthy. To be clear, the scientific consensus is actually that eating meat is relatively unhealthy. [1] I'm not sure what to say about your intuition, but this study doesn't say what you think makes sense, and some of your premises are in error.

[1] https://www.webmd.com/diet/news/20200203/meat-still-isnt-hea...

Do you consider seafood meat?

Meat generally means red meat, as opposed to pork, poultry or fish. Seafood was probably once very healthy, but now the oceans are continuously poisoned, mercury content is an issue. If you eat a lot of fish, choose farmed fish. I used to love shellfish until I was poisoned by broiled lobster, then again a year later with another broiled lobster. Also, there were incidents with both a piece of fish from Applebees (bad judgement), and a fried catfish prepared by a girlfriend's mother. There's no sick like that. In all four instances, I don't think I could keep anything down for two weeks afterwards. If you caught a fish today, I'd probably eat it, but I won't touch a fish more than a half-hour's drive from the ocean.

Pork is a red meat BTW.

Thanks. ><

All-cause mortality is so multivariate, and so easily confounded, that an uncontrolled study of only 1,139 people in one region is meaningless.

As others have pointed out, food diaries are BS. Did all 1,139 people weigh their meat before they ate it? They mention "food frequency questionnaires" ("let's see, that's 157 grams of chicken today").

not surprising because eating properly plant-based can be challenging, especially in old age which is less forgiving. Eating animals is a decent hedge. But my money is where my mouth is that my proper plant-based diet will win out.

Except that's contradicted by this study. An example of witchcraft over science - believing what you want to believe, even when presented with its contradiction.

There are dozens of studies that support plant-based diets as reducing all-cause mortality. THIS study is the outlier, and thus demands a pretty high burden of proof.

Is it really much of an outlier? I eat a plant-based diet but most of what I have seen has been quite mixed

Food studies are always all over the place.

The only real consistency is that eating loads of processed food (think chips/soda) is strongly correlated with health issues.

Food studies are all over the place because they never account for genetics.

Look up Nutrigenomics to understand more, But a great example is changes in the FADS genes and how they impact the intake of long and short chain Omega 3s

https://www.mdpi.com/2072-6643/10/6/758

Unless they are testing people with the same genetics, a meat versus plant diet will continue to result in different outcomes.

I think what they are saying is that animal meat has nearly everything a human body needs in terms of mineral, vitamin, fats, etc. On the other hand unless you take extreme care a plant based diet will often be lacking one or more critical resources for the body.

This study cannot be used to contradict or support hypotheses. The study is too small, local (do you live in Tuscany?), and is highly confounded. What other traits covary incidentally with eating more or less meat? Hundreds. This is a paper that may advance a few careers but it will not advance our understanding of aging and health span.

I tend to feel this is true. If anything this study shows that for many people the efforts they put into living longer via steering their diet might not pan out in the long run as other factors probably have more effect.

Why ignore the other articles the conclude the opposite?

This study is just a prospective cohort study, not a gold standard RCT or anything close to it.

Also just one region in one country. How do you extraplote that globally?

Those eating more animal protein must have also been eating more animals fat. Is there a particular reason protein gets the credit in this study?

The idea that a wholly vegetarian or vegan diet is healthier than sometimes eating meat is extremely questionable.

It completely flies in the face of common sense and only really makes any headway at all due to the "everyone should do less" variety of environmentalism.

The population used for this study doesn’t seem ideal for studying the impact of being vegetarian

> A prospective cohort study including 1,139 community-dwelling older adults (mean age 75 years, 56% women) living in Tuscany, Italy, followed for 20 years

Big surprise, meat consumption and generally better nutrition correlates with longer life expectancy over the centuries. It's only in very recent times that overconsumption has become a problem.

In order for meat to be considered healthy, it could only be consumed in relatively strict moderation, though you'd have to eat a heck of a lot of fruit for it to kill you (I expect the lethal dose is an estimation). Even two servings of meat a week measurably increases risk of mortality and increases risk of heart disease and stroke. Eat what you like, but don't kid yourself. What the meat lobby says is generally a lie.

Sleeper (1973): "No deep fat, or steak, or cream pies?"

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