Vegetarian, Pescatarian, or Meat-Eater — The Data-Driven Answer on Who Lives Longer

When researchers want to compare eating patterns and lifespan, a few landmark studies do most of the heavy lifting. The headline finding comes from the Adventist Health Study-2, which followed more than 73,000 people and was published in JAMA Internal Medicine in 2013. In that data, pesco-vegetarians — people who skip other meat but eat fish — had the lowest death rate of any group, about 19 percent lower than non-vegetarians, with vegans and lacto-ovo vegetarians close behind.

That sounds decisive until you look at a second, equally serious study. A 2016 analysis of more than 60,000 adults in The American Journal of Clinical Nutrition found almost no difference in overall mortality between vegetarians and comparable meat-eaters. Same question, two excellent datasets, two different answers. That tension isn't a flaw in the research — it's the whole story, and we'll untangle it shortly.

First, here's how the patterns stack up across the major outcomes. Think of this as the scorecard, then we'll talk about why the columns don't all point the same way.

All figures are from observational studies and reflect associations, not proof that diet alone caused the difference. (A "Group 1" classification reflects the strength of the scientific evidence that something can cause cancer, not the size of the risk.) "Meat-eater" covers everything from a fast-food diet to a vegetable-rich Mediterranean one — a major reason results vary between studies.

Before we go further, it helps to be precise about what these labels actually mean, because two of them are tidy and one is a catch-all that hides enormous variety.

A vegetarian eats no meat or fish. Within that, a lacto-ovo vegetarian still includes dairy and eggs, while a vegan avoids all animal products. A pescatarian skips meat but eats fish and seafood, and tends to build the rest of the plate around vegetables, grains, and legumes. Both are reasonably well-defined: you can picture the fridge.

The meat-eater category is where things get slippery. It's the loosest of the three by far, because it describes someone living on fast food and white bread and someone cooking a vegetable-forward Mediterranean dinner with fish twice a week and a steak once a month. Those two people share a label and almost nothing else.

That heterogeneity matters more than it sounds. When a study's meat-eaters happen to eat well, the gap with vegetarians shrinks or disappears entirely — which is exactly what happened in the UK data. So when you read "meat-eaters die sooner," the fair question is always: which meat-eaters? The answer usually explains most of the disagreement between studies.

Here's the surprise tucked inside the data. The pescatarian pattern keeps surfacing near the top, and there's a sensible reason why: it pairs a plant-heavy diet with the one animal protein that has decades of solid cardiovascular research behind it.

In the Adventist study, pesco-vegetarians didn't just post the lowest overall death rate — they also had roughly a 35 percent lower risk of dying from heart disease than non-vegetarians. That's the combination that makes the pattern compelling: plants doing what plants do, plus fish providing long-chain omega-3 fatty acids that have been associated with cardiovascular benefits. It's less a single hero food than a well-balanced team.

The fish piece has its own backing. The American Heart Association recommends one to two seafood meals a week, with an emphasis on fatty fish like salmon, sardines, or trout, to lower the risk of heart disease, ischemic stroke, and sudden cardiac death. That's a modest, specific target — not a "more is always better" prescription — and it lines up neatly with what the longest-lived diet groups were already doing.

Now for the fact that resolves the contradiction we hit earlier — and it's the single most important idea in this entire topic.

When researchers compared UK vegetarians not to the general population but to health-conscious meat-eaters — people who also exercised, smoked less, and watched what they ate — the overall mortality difference essentially vanished, landing at a rate ratio of 1.02. Read that again, because it's easy to skim past. A lot of what looks like "vegetarians live longer" isn't the absence of meat at all. It's that people who choose vegetarian diets tend to do a whole bundle of other healthy things at the same time.

Researchers call this the healthy-user effect, and once you see it, you can't unsee it. The Adventist cohort makes the same point from the other direction: even the non-vegetarians in that study smoked little, moved more, and drank less than the average American, which is part of why vegetarian-type diets looked so good there. The comparison group quietly drives the result.

This is also why a study like the one comparing UK vegetarians to similarly health-minded omnivores is so valuable. It strips out a lot of the noise and asks a fairer question: holding lifestyle roughly equal, how much does the food itself move the needle? It's a reminder that the habits clustering around a diet can matter as much as the diet — many of the same ones that turn up in 12 things people who age well have in common.

Once you accept that lifestyle does a lot of the work, a clearer pattern comes into focus: it's less about whether you eat meat and more about what fills the plate overall.

A 2016 study in JAMA Internal Medicine that followed more than 130,000 people found that higher intake of animal protein — particularly from processed and red meat — was linked to higher mortality, while higher plant-protein intake was linked to lower mortality. Even more telling, swapping a small share of calories from processed red meat for plant protein, like beans or nuts, was associated with lower risk. The protein source, not just the protein, seemed to matter.

The cancer picture points the same way. The World Health Organization classifies processed meat as a known cause of colorectal cancer and unprocessed red meat as a probable one — a distinction that matters more than most headlines let on.

The broader cancer data tells a consistent story. In a 2022 analysis of nearly half a million people in BMC Medicine, low-meat eaters, fish-eaters, and vegetarians all had a lower overall cancer risk than regular meat-eaters — with vegetarians also showing lower rates of colorectal and prostate cancer specifically.

Notice what's doing the work in all of this. It isn't the vegetarian label; it's the steady drumbeat of more plants and less processed meat. A vegetable-rich omnivore and a thoughtful vegetarian end up looking a lot alike on these charts. If the protein side of that is what's nagging at you, our breakdown of protein timing vs. protein total gets into how much the source and amount really matter.

Honesty means including the finding that complicates the plant-based story, not just the ones that flatter it.

One large UK study, published in the BMJ and following participants for 18 years, found that vegetarians had about a 20 percent higher rate of stroke than meat-eaters — equal to roughly three extra cases per 1,000 people over a decade — driven mostly by hemorrhagic (bleeding) stroke. Fish-eaters, notably, didn't show the same increase. The researchers floated possible explanations, including lower circulating cholesterol and lower intake of certain nutrients, but they were careful not to overstate it.

It's worth keeping this in proportion. The absolute numbers are small, the finding comes from a single cohort, and it hasn't been reliably reproduced elsewhere. The sensible reading isn't "stop eating plants" — it's that a plant-based diet works best when it's nutritionally complete, with attention to the nutrients that are easy to come up short on.

Time to put it together honestly, with the confidence each claim deserves.

At the top, by a nose, sit the pescatarians. Theirs is the most consistent association with the lowest mortality, strongest in the Adventist data. Call that moderate confidence — one strong cohort, pointing the same direction as the broader evidence on fish and plants.

Just behind them, and often indistinguishable, are vegetarians and vegans. They show generally lower heart-disease and cancer risk, but their overall-mortality edge depends heavily on who they're compared against, and it carries the stroke asterisk. That's moderate but conflicting confidence — real benefits, genuinely mixed results.

Then there are meat-eaters, who span the widest range of outcomes precisely because the category is the widest. A plant-rich diet with modest, mostly-unprocessed meat looks far more like the groups above it than like a processed-meat-heavy diet does. The one thing we can say with strong confidence is the narrow part: high intake of processed and red meat is reliably linked to worse outcomes.

So if you want the single most defensible answer the data supports: a plant-forward diet with fish as the main animal protein — the pescatarian pattern — has the most consistent link to a longer life. But the gap between that and a careful vegetarian, vegan, or even a vegetable-rich omnivorous diet is small, and most of it comes down to the same handful of habits. If you're curious how these patterns stack up against other popular eating styles, we line them up in 7 diets ranked by what the longevity science actually supports.

You don't need to pick a tribe to borrow what worked. Here's what the longest-lived groups in these studies tended to have in common — framed as options, because the right plate looks a little different for everyone.

They built meals around plants and legumes. That's the common thread running through every group that did well, vegetarian and pescatarian alike, and it's the easiest place to start. When fish was on the menu, it tended to be the default animal protein rather than an occasional treat — the American Heart Association's one-to-two-meals-a-week target is a simple, evidence-backed anchor if you want one.

They also leaned away from processed meat more than anything else. If a single change carries the clearest signal in this entire article, it's trimming bacon, deli meats, and hot dogs. And reassuringly, it doesn't have to be all-or-nothing: the UK Biobank data found that even low meat-eaters had a lower cancer risk than regular meat-eaters, so cutting back genuinely counts. For anyone eating fully plant-based, the longevity edge holds up best when the diet stays nutritionally complete — vitamin B12 above all, with an eye on omega-3s, iron, and vitamin D.

If you want a closer look at the plants that keep showing up on the longest-lived plates, foods for longevity: what long-lived populations eat is a natural next read.

This article is for general information and is not a substitute for medical advice. Diet is one piece of a long, healthy life — not a replacement for medical care. If you have a chronic condition, take prescription medications, are pregnant, or are considering a major change to how you eat, talk with your doctor or a registered dietitian first.

Angela Nightingale writes about everyday health for Active Living, covering nutrition, prevention, and the evidence behind the choices that show up on most people's plates.