Do Vegetarian and Vegan Diets Get Riskier as You Age? What Two New Studies Reveal

In this episode we discuss:

• How aging changes nutritional requirements 
• Micronutrient concerns in vegetarian and vegan diets 
• Why protein quality matters
• Why long-term vegetarian and vegan diets may leave older adults particularly vulnerable to inadequate protein
• Whether vegetarianism increases longevity
• Approaches for prioritizing protein and nutrient density

Show notes:

• “Mortality in vegetarians and comparable nonvegetarians in the United Kingdom” by Appleby, P. N., et al.
• “Evidence-based recommendations for optimal dietary protein intake in older people: A position paper from the PROT-AGE Study Group” by Bauer, J., et al.
• “Eliminating animal products from the diet puts Dutch older adults at risk of micronutrient deficiencies: A simulation study” by Borkent, J., et al.
• “A vegan dietary pattern is associated with high prevalence of inadequate protein intake in older adults; a simulation study” by Borkent, J. W., et al.
• “Vitamin B-12 status, particularly holotranscobalamin II and methylmalonic acid concentrations, and hyperhomocysteinemia in vegetarians” by Herrmann, W., et al.
• “Vegetarian diet and all-cause mortality: Evidence from a large population-based Australian cohort – the 45 and Up Study” by Mihrshahi, S., et al.
• “How prevalent is vitamin B12 deficiency among vegetarians?” by Pawlak, R., et al.
• “Risks of ischaemic heart disease and stroke in meat eaters, fish eaters, and vegetarians over 18 years of follow-up: Results from the prospective EPIC-Oxford study” by Tong, T. Y. N., et al.
• “Long-term vegetarian and vegan diets in older adults are associated with inadequate intakes of protein and micronutrients” by Wildemast, S., Verlaan, S., & Grootswagers, P.
• A deeper dive on whether vegetarian and vegan diets are better for the environment
• Learn more about the Adapt Naturals Core Plus Bundle or take our quiz to see which products best suit your needs
• If you’d like to ask a question for Chris to answer in a future episode, submit it here
• Follow Chris on Instagram or Facebook

Hey everybody, Chris Kresser here. Welcome to another episode of Revolution Health Radio. Today we’re going to talk about something I’ve been asked about for the better part of two decades, and that has taken on a new urgency in the last few years: What happens to people on vegetarian and vegan diets as they get older? If you follow health news at all, you’ve seen the push. Dietary guidelines in the Netherlands, Germany, Denmark, and Canada have all shifted toward plant-forward eating. The EAT-Lancet Commission wants the whole world eating a lot less meat. Every other longevity influencer seems to be telling you that the path to a long life runs through a plate of lentils. If you’re in your 60s or 70s, or you’re helping a parent who is, you may have wondered whether you should be eating less meat or not at all, and whether the answer changes with age.

I have a somewhat unusual vantage point on this. Over my 15 years in clinical practice, I worked with a lot of vegetarians and vegans. I respected their reasons, and I still do. But I also ran comprehensive blood work on every new patient before our first visit, and it got to the point where I could tell from the labs alone, before the patient ever told me what they ate, that I was looking at a vegetarian or a vegan. The pattern was that consistent. I’ll get into what that pattern looked like later in the episode.

What prompted this particular show is two new studies out of the Netherlands, both published in 2026 that look specifically at older adults. One is a large simulation using national food survey data on more than 600 people over 65. The other one is one of the very few studies ever done on people in their 70s who have been vegetarian or vegan for around 40 years. Not new converts, but lifers. Together, they paint a clearer picture than we’ve had before of what happens to protein and micronutrient intake when older adults remove animal foods, and it’s not a reassuring picture. I’ve argued for years that vegetarian and vegan diets fall short of a whole-food, omnivorous diet at any age because they lack the nutrients that animal foods supply in the most bioavailable forms. What these new studies add is that the gap widens as we get older. Aging changes how much protein we need, how well we absorb nutrients, and how much margin for error we have. So the shortfalls the younger body can partly paper over start showing up as lost muscle and bone in someone in their 70s. This is happening at the same time public health advice is pushing everyone at every age toward eating fewer animal foods.

By the end of this episode, you’ll understand why the nutritional weakness of plant-only diets matter more as you age, what the two new studies found about protein and micronutrients in older adults eating plant-only diets, why the standard lab tests used to check nutrient status can miss real problems, what the best mortality studies say about whether vegetarians live longer than meat eaters, and what I’d recommend whether you eat meat or not. Let’s dive in.

Okay, let’s start with why age raises the stakes, because this is the piece that most of the plant-based longevity conversation skips over entirely. The nutrient gaps in vegetarian and vegan diets are the same at any age. What changes is how much room your body has to absorb those gaps. When you’re young, your body is typically good at building and maintaining muscle in response to protein. As we age, that response gets blunted. Researchers call this anabolic resistance, and what it means in practice is that an older adult needs more protein per meal, and more protein per day, to get the same muscle-building signal a younger person gets from less. At the same time, appetite tends to decline, total food intake drops, and stomach acid production falls, which impairs the absorption of B12, iron, zinc, and calcium. So you have a body that needs more of certain nutrients at exactly the moment it’s eating less food and absorbing it less efficiently.

This is why the protein recommendations for older adults have been revised upward. The official RDA of 0.8 grams per kilogram of body weight was never designed for aging bodies. A 2013 position paper from the PROT-AGE Study Group, an international panel of geriatric and nutrition researchers, recommended at least 1 to 1.2 grams per kilograms for healthy people over 65, 1.2 or more for those who are active, and 1.2 to 1.5 for those dealing with acute or chronic illness. In my own work, I have long recommended 1.2 to 1.6 grams per kilogram for most older adults, with the higher end for anyone who’s exercising, which of course everyone over 60 should be. For a 150-pound person, that’s roughly 80 to 110 grams of protein a day. It’s a lot of protein, and it’s hard to get from plants alone. Plant proteins are lower in total protein per calorie, and they’re often short on one or more essential amino acids, particularly lysine and methionine, and they’re less digestible because of the fiber and antinutrients that come along with them. Those are limitations at any age, but a younger person with a big appetite and a responsive metabolism has more room to compensate. At 75, that room is mostly gone.

The same logic applies to micronutrients. Older adults on an ordinary mixed diet are already falling short on several nutrients. In the Dutch simulation study I’ll get to in a minute, the baseline diet of these older adults, which included meat, fish, dairy, and eggs, was already low in riboflavin, vitamin B6, folate, and calcium, and vitamin A and selenium were also low in women. That’s the starting point. When you take a population that’s already running thin on nutrients and remove the most nutrient-dense foods from their diet, you’re starting from a deficit and digging a deeper hole.

That brings us to the first of the two new studies. A 2026 paper in Current Developments in Nutrition took data from the Dutch National Food Consumption Survey, 607 community-dwelling adults age 65 and older, and asked a simple question: If these people swap their animal foods for plant-based alternatives, food by food, what would happen to their micronutrient intake? The researchers modeled five scenarios: Replacing 40 percent of meat and fish, replacing 80 percent, going pescatarian, going vegetarian, and going fully vegan. They used realistic substitutions, the kind of products sold in Dutch supermarkets, including fortified meat replacers and fortified plant milks. In the 40 percent replacement scenario, nothing new fell below the threshold. Intakes of most micronutrients dropped a little, but no additional nutrients became inadequate. That’s maybe the one piece of good news in this episode, and it’s consistent with what I’ve said for years. Eating a little less meat is often fine, especially if you consume organ meats and shellfish, which are far more nutrient dense than muscle meats, and some people can cut back moderately and be no worse off nutritionally. I say “some people” deliberately because how well anyone tolerates a lower intake of animal foods depends on individual variation, and that variation is enormous. Genetics and epigenetics play a role. So do lifestyle factors like stress, sleep, and physical activity, and so does gut health, which determines how much of what we eat we absorb.

One of the clearest examples is nutrient conversion. Plants don’t contain vitamin A. They contain beta-carotene, which your body has to convert into retinol, the active form of vitamin A. And some people do that conversion efficiently, while others, because of common genetic variants, convert very little. The same is true for the omega-3s. Flax and walnuts give you alpha-linolenic acid, or ALA, and the conversion into EPA and DHA. the forms your brain and heart use, ranges from small to almost non-existent. This is why one person can do reasonably well on a vegetarian or vegan diet for years, at least for a while, and another person declines within months. It’s also why following an influencer is a poor strategy. Someone like Rich Roll is running ultramarathons on a vegan diet and thriving, and thousands of people watch that and assume they’ll get the same result. Some might, many won’t, and the difference has nothing to do with willpower and everything to do with the body they were born with.

Once you go further, the picture changes. In the 80 percent replacement, pescetarian, and vegetarian scenarios, nearly every micronutrient declined, and several new ones crossed into inadequate territory. Niacin became low across the board. Vitamin A and thiamin became low in men. Vitamin B6, which was already marginal in the baseline diet, was now inadequate in more than half of older adults. B6 in particular is directly tied to physical function and mobility in older people, and the researchers themselves pointed to that connection. In the vegan scenario, to use the author’s own phrasing, nearly all micronutrient intakes were low. The exceptions were a handful of nutrients that legumes, grains, and fortified replacers happened to supply, like thiamin, folate, copper, iron, vitamin E, magnesium, phosphorus, and potassium in men. Everything else, including vitamin A, riboflavin, niacin, B6, B12, calcium, zinc, and selenium fell below adequacy for a substantial share of the population.

Do vegetarian and vegan diets become harder to maintain nutritionally as we age? This episode offers practical considerations for meeting protein and micronutrient needs —including strategies for people who eat animal foods as well as those who choose to remain vegetarian or vegan. #ChrisKresser #plantbaseddiets #aging

The iron numbers deserve a closer look here. Iron stayed high in the vegan scenario, and even increased, but only because of where it came from. The plant-based meat replacers in the Netherlands are heavily fortified with iron, often containing more than the meat they replace, and soy milk has about a milligram of iron per glass that dairy milk doesn’t. But every bit of that iron is non-heme iron, which the body absorbs at anywhere from 1 percent to about 23 percent compared to 15 to 35 percent for the heme iron in meat and animal products. The researchers were candid that despite the higher numbers on paper, it’s unclear whether enough iron would be available. I’d go further than that. In my experience, it usually isn’t. The second detail is zinc. Zinc dropped substantially in the vegan scenario, and it dropped for a specific reason: Those same meat replacers are fortified with iron and B12, but almost never with zinc. Meat naturally provides a whole spectrum of micronutrients, and its replacements provide two of them, added back artificially.

This same research group published a companion paper in 2024 in the Journal of Nutrition, Health, and Aging, using the same 607 older adults, but looking at protein. In the vegan scenario, utilizable protein, meaning protein adjusted for digestibility and amino acid quality, dropped by nearly 50 percent, and 83 percent of participants fell below the estimated average requirement, which is a lower bar than the RDA and covers the needs of only half the population.

Now, a simulation is a model, not a measurement. You can reasonably ask whether real vegetarians eat like a computer swapping out a hamburger for a soy patty. The authors raise this limitation themselves and noted that people who choose plant-based diets often eat more legumes, vegetables, and whole grains than their models assumed. So this is a fair objection. That objection is exactly why the second study we’re going to talk about today is so valuable. A 2026 paper in the Journal of Nutrition went out and found the real people. The researchers recruited residents of a vegetarian retirement community in the Netherlands called Ommershof, where every resident has been vegetarian for at least three years. They ended up with 26 people, 20 vegetarians and six vegans with a median age of 76. The vegetarians had been vegetarian for a median of 42 years. The vegans had been vegan for 10 years, after an average of 31 years as vegetarians. These are people who have organized their entire adult lives around this way of eating, and they’re living in a community built to support it. If anybody should be getting it right, it’s them. The researchers had them keep three-day weighed food records, then compared them to 771 omnivorous Dutch adults of the same age and body weight from the national survey. On protein, 83 percent of vegans and 40 percent of vegetarians fell below the RDA, compared with 25 percent of omnivores. Half the vegans didn’t even reach the estimated average requirement. Median protein intake was one gram per kilogram in omnivores, 0.9 in vegetarians, and 0.6 in vegans. Not a single vegan reached the 1.2 gram per kilogram target for older adults, and only 10 percent of the vegetarians did.

Protein quality was even worse than quantity. The researchers used a measure that accounts for whether each meal delivers enough of every essential amino acid to trigger muscle building in an older body. Every vegan meal in the study had at least one limiting amino acid, usually lysine or methionine. Over the full day, 100 percent of the vegans and 83 percent of the vegetarians fell short of adequate protein quality. The median vegan score was 0.5, meaning they were covering roughly half of their daily protein requirement in a form their bodies could use. On micronutrients, both groups fell short on calcium, zinc, vitamin B12, and vitamin D, and the vegans also fell short on iron and folate. Vegan B12 intake from food was 0.1 micrograms a day, against a Dutch requirement of 2.8. That’s essentially zero, and these were people who mostly took supplements. Two-thirds of the vegans took calcium, half took vitamin D, and a third took B12. Even with supplements added in, calcium and folate requirements still weren’t met, and the vegans over 70 still didn’t reach adequate vitamin D.

Now, 26 people is a small study. Six vegans is a small group, and the authors say so plainly. What makes it meaningful is that it points in exactly the same direction as the simulation, and as decades of earlier research in younger vegetarians. The people with the most experience and the most support were still coming up short on protein and on the same short list of nutrients we’ve been talking about for 20 years. That short list is exactly what I used to see on the lab reports.

When I was in practice, every new patient had blood drawn before our first appointment, so I’d sit down with the results before I’d met the person. Over time, a pattern emerged that I came to recognize almost instantly: low or borderline serum B12, and when I’d ordered it, elevated methylmalonic acid and homocysteine, which are the functional markers that tell you B12 isn’t doing its job at the cellular level. Low ferritin, sometimes with hemoglobin still in the normal range, which is what iron depletion looks like before it becomes anemic. Low zinc, often with high copper. Low vitamin D, low omega-3 index. When I saw three or four of these together, I’d write “vegetarian?” in the margin of the intake form. If the deficiencies were more severe, I could often predict it was a vegan, and I was rarely wrong. Patients would sometimes be startled that I’d guessed before they’d told me.

Conventional lab reference ranges are designed to detect frank deficiency, the level at which you develop clinical disease. They are not designed to identify optimal levels. A serum B12 of 250 picograms per milliliter is “normal” on most lab reports in the U.S., and in my clinical experience and in the research, patients at that level very often had elevated homocysteine and early symptoms like fatigue, numbness, and brain fog. There are some studies showing irreversible nerve damage at B12 levels ranging from 250 to 400 picograms per milliliter, which are in the normal lab range at most labs. The same goes for ferritin, vitamin D, and zinc. Normal means you don’t have scurvy or pernicious anemia, which is a long way from thriving.

Serum B12 in particular is a poor marker because it measures total cobalamin in the blood, including forms your cells can’t use, and it doesn’t drop until deficiency has been developing for a while. A 2003 study in the American Journal of Clinical Nutrition compared serum B12 to holotranscobalamin, which is the fraction of B12 that’s available to your cells. Using the standard serum test, a modest number of vegetarians looked deficient, but using holotranscobalamin, 77 percent of vegetarians and 92 percent of vegans were deficient, compared with just 11 percent of omnivores. A 2013 review in Nutrition Reviews that pooled studies using these more sensitive markers found B12 deficiency rates among elderly vegetarians ranging from 11 percent all the way up to 90 percent. Apply that to the two Dutch studies. They measured intake against the estimated average requirement and the RDA, which are themselves set to prevent deficiency, not to promote optimal function. If those thresholds are already conservative, and the people falling below them are already a large share of the population, then the true proportion of older vegetarians and vegans who are functionally short on these nutrients is almost certainly higher than what these studies report, and the numbers are already very high. So, if anything, these papers are understating the problem, especially once you stack a diet with near-zero B12 on top of an aging gut that absorbs B12 poorly to begin with.

So, given all this, you’d hope vegetarians and vegans at least live longer, because if they did, the nutrient trade-offs might be worth it. The idea that vegetarians live longer comes mostly from studies of Seventh Day Adventists, and those studies compared Adventist vegetarians to the general population. The trouble is that Adventists also don’t smoke, don’t drink, exercise regularly, sleep well, and have strong social ties. Every one of those independently predicts a longer life. When you compare people who make one health-conscious choice to people who make none, the health-conscious group will always win, and you can’t tell which choice did the work. Epidemiologists call this the healthy user bias, and it’s the single biggest reason that the vegetarian longevity story got as much traction as it did. The better studies compare vegetarians to health-conscious omnivores, people recruited from the same health food store and the same social circles. A 2016 paper in the American Journal of Clinical Nutrition pooled two large British cohorts, more than 60,000 people, including over 20,000 vegetarians, about 2,000 of whom were vegan, followed for over a million person-years. There was no significant difference in all-cause mortality between vegetarians and regular meat eaters. The hazard ratio for vegetarians was 1.02, which is a statistician’s way of saying identical. These were all health-conscious people to begin with, which is exactly the comparison that matters.

The largest single study, published in Preventive Medicine in 2017, followed 243,000 Australians over age 45 for six years. After adjusting for smoking, exercise, alcohol, weight, and existing disease, there was no significant difference in mortality between vegetarians and meat eaters. The same was true for pesco-vegetarians and semi-vegetarians. A 2019 analysis in BMJ adds a wrinkle that rarely makes it into the headlines. It followed 48,000 people in the EPIC-Oxford cohort for 18 years. Vegetarians did have a 22 percent lower rate of ischemic heart disease, which is real and worth acknowledging. But they also had a 20 percent higher rate of stroke, mostly hemorrhagic stroke, and that association did not go away when the researchers adjusted for the usual risk factors. Lower B12, higher homocysteine, and lower intake of certain fats and amino acids have all been proposed as possible reasons. Whatever the mechanism, you’re trading one risk for another rather than eliminating risk. Put the mortality evidence together, and health-conscious vegetarians and health-conscious omnivores live about the same length of time. There is no longevity bonus for giving up animal foods. You’d be paying the nutrient costs we just walked through, costs that only grow as you age, in exchange for a benefit the best evidence says doesn’t exist. Longevity is not a good reason to choose a plant-only diet. Ethics or environment are another matter, and I’m not going to get into those in the context of this show. But if you’re doing it because you believe it will help you live longer, the science isn’t on your side.

So let’s talk about what to do with all of this, because I know I have listeners on both sides of this question. If you eat meat and you’re over 60, the first priority is protein. Aim for 1.2 to 1.6 grams per kilogram of body weight per day, and spread it across your meals, because your muscles can only use so much at once. In practical terms, that’s 30 to 40 grams at each meal, and breakfast is where almost everyone falls short. In the Dutch study of long-term vegetarians, protein quality was lowest to breakfast in every group, including the omnivores, because breakfast in most of the Western world is bread and something sweet. Eggs, Greek yogurt, leftover fish or meat, a protein-rich smoothie, whatever works for you, but get 30 grams in at least before noon. Second, lean into the most nutrient-dense animal foods rather than just eating more of everything. Eggs for choline and B12. Fatty fish and shellfish for EPA, DHA, zinc, iodine, and selenium. Full-fat dairy, if you tolerate it, for calcium and protein. Liver or other organ meats or shellfish once a week, because nothing else comes close for vitamin A, B12, copper. You don’t need a lot. A few ounces a week, a few servings of seafood, an egg or two a day, and muscle meats as you wish, and you’ve covered most of what the vegan scenario in the simulation lost. Third, if you want to eat less meat for whatever reason, that’s fine. The 40 percent replacement scenario in the simulation study caused no new deficiencies, at least according to the RDA. But you have to keep in mind that that’s kind of the minimum and not configured for optimal health. So I’m still a little dubious of that finding. But if you cut your meat intake, let’s say by a third, you can replace it with fish, eggs, dairy, and legumes rather than highly processed meat analogs, and you’ll still probably be in good shape.

For patients that wanted to do this when I was in practice, I would suggest a serving or two of organ meat and a serving or two of shellfish per week. Those are so nutrient dense that you could probably remove muscle meats almost entirely from your diet, and if you just ate shellfish, organ meats, egg yolks, dairy, and maybe some fish, you would get what you need from a nutritional perspective.

If you’re a vegetarian or vegan and you plan to stay that way, what I’d ask is that you take the nutritional side of it far more seriously than most people do, and more seriously with every passing decade. Start with testing, and insist on the right tests. Not just serum B12, but methylmalonic acid and homocysteine if you’re in the U.S., or holotranscobalamin if you’re in Europe. That test is unfortunately difficult to get in the U.S. outside of research settings. Ask for ferritin rather than just hemoglobin, and a full iron panel, along with serum zinc, vitamin D, and an omega-3 index. Then interpret the results against optimal functional ranges, not the lab’s flagged range. If your B12 is in the low 200s, it will show up on LabCorp request as normal, and your doctor may say it’s fine. But in my experience, and again according to the research, it’s usually not.

Supplement B12 at a meaningful dose, not a token one. For maintenance, the doses I used to recommend range between 250 micrograms to 1,000 micrograms a day of methylcobalamin or hydroxocobalamin. And if your markers show you’re already deficient, you can work with your practitioner to target a higher dose. Take vitamin D, and get your level checked. Consider an algae-based EPA and DHA supplement, because the conversion from plant-based omega-3s with alpha-linolenic acid, like from flax or walnut, is too low to rely on. Zinc and iodine are worth considering as well, especially for vegans.

On protein, treat every meal as a protein opportunity. The Dutch study found that some plant-based meals did hit full protein quality, and they all followed the same pattern: A substantial serving of legumes combined with grains, nuts, or seeds, with tofu or tempeh doing a lot of the heavy lifting because soy is one of the few complete plant proteins. Don’t rely on bread with hummus for lunch, which is what the vegans in that study were eating when they ate lunch at all, and only half of them did. Be honest with yourself about portion size too. A 76-year-old who eats 500 fewer calories a day than her omnivore neighbor, which is what the study found for vegans, has very little room to hit protein targets unless a large share of those calories is protein. If your ethics allow it, consider adding eggs, dairy, or fish back in. The vegetarians in that study did meaningfully better than the vegans on almost every measure, and dairy was the main reason. I’ve seen many longtime vegans in their 60s make peace with eating eggs or fish, not because they stopped caring about animals, but because they realized they also needed to care about staying strong enough to hold their grandchildren. We have spent a decade treating dietary advice as if it were one-size-fits-all, first with the idea that one diet is optimal for everyone, and now with the idea that one diet is optimal for the planet and therefore for every person on it. The idea that a plant-based diet is better for the planet is widely accepted as dogma in the mainstream establishment. But as I have written and spoken about at length in other venues, that is not necessarily true. And in fact, there’s a lot of evidence that suggests otherwise. Again, I’m not going to talk about that in the context of this show today, but I’ll put some links in the show notes where you can read a little bit more about that.

Regardless of your beliefs about the environmental impact of eating animal foods on the planet, a 75-year-old body is not a planet. It has thinner margins and less time to recover from slow deficiency. Whatever your reasons for eating the way you do, your nutritional strategies should get more careful as you age, not less. Longevity is more than a number of years. It’s whether you can still carry your own groceries and get up off the floor at 85, and whatever else your diet does for you or the planet, it has to do that first.

Thanks for listening. You can find show notes and links to all the studies I mentioned at ChrisKresser.com. If you have questions about this episode or suggestions for future topics, head over to ChrisKresser.com/podcastquestion and leave me a message. I read all of them, and your questions help shape the content I create. Until next time, be well.