Another diet does just as well, so you don't need to be vegan
Often true, and it settles less than it seems. The diets held up as counterexamples are overwhelmingly plant-based with animal foods as a garnish, which is evidence for the plants rather than against them. And if the health gap really is small either way, then health has stopped being the deciding question and what happens to the animals becomes it.
If the question is what keeps people healthy, several well-studied diets do at least as well as a vegan one. The Mediterranean pattern has the stronger trial evidence, needs less planning and needs no supplements. Cohort studies favouring vegans compare them with average eaters rather than with people eating well. Against a good Mediterranean or Okinawan diet, any vegan advantage is small, and doctors are right to recommend the diet people can actually stick to.
This one arrives with a different diet attached each time: Mediterranean, Okinawan, the Blue Zones, pescatarian. The shape of the argument does not change, so it is worth taking the strongest version of it, which is the Mediterranean one.
Start with what these diets have in common. Almost every long-lived population offered as a counterexample eats overwhelmingly plants, with animal foods as a garnish rather than the centre of the plate. Okinawa was built on sweet potato. The Mediterranean pattern is vegetables, legumes, whole grains, fruit, nuts and olive oil, with a little fish and dairy and very little red meat. Pointing at these populations is pointing at diets much closer to a vegan one than to the diet of almost anyone making the argument.
On health alone, the claim is a fair reading of the evidence. The Mediterranean diet has strong trial support, including the PREDIMED trial, and doctors are taught to recommend it first. Large cohort studies such as EPIC-Oxford and the Adventist Health Study suggest plant-based eaters do well on heart disease, diabetes and obesity. They also show some weak spots for vegans, such as a higher fracture risk in EPIC-Oxford. Direct comparisons between a well-planned vegan diet and a well-followed Mediterranean one are thin, and a modest difference either way is a reasonable guess.
The benefits of these patterns are usually put down to the plant base and to cutting out processed and red meat. That is evidence the plants are doing most of the work.
The two are also not opposites. Lentils, chickpeas, beans, greens, tomatoes, bread, olive oil and nuts are the core of Mediterranean cooking. Dropping the fish and cheese leaves a vegan diet that keeps nearly everything thought to make the pattern healthy. The real extra cost is a B12 supplement and some care over omega-3, iodine and calcium.
Which leads to the main point. If the two diets are close on health, health gives no strong reason to go vegan. It also gives no strong reason to keep eating animals. What separates them is then mostly what happens to the animals: the fish caught, the cows kept in milk, the calves taken away. Better-run farms cause less harm than worse ones, but they do not make that harm necessary, and a small health gap leaves that question entirely open.
- A Mediterranean diet is almost as healthy as a vegan one
- A pescatarian diet beats a vegan one for longevity
- Blue Zone populations all eat some animal foods
- The Okinawans live longest and they eat fish
- You can be just as healthy on a Mediterranean diet
Different wording, same argument. The response above answers all of them.