N=133,000 over 40 year time period
Observational study so limitations may apply but the findings do hold after adjusting for a large list of factors I will quote here:
educational attainments, family history of dementia, menopausal status with hormone use status, total energy intake, regular antidepressant drug use, history of depression, BMI, moderate-to-vigorous physical activity, neighborhood SES [socioeconomic status], marital status, living arrangement, smoking status, histories of hypertension, diabetes, and hypercholesterolemia and intakes of sugar-sweetened beverages, fruits, vegetables, whole grains, poultry, fish, eggs, nuts and legumes, low-fat dairy products, high-fat dairy products, and alcohol
Luckily we now have populations that eat only animal sourced food and populations who only eat plant foods
It’d be really good to get a prospective study comparing those groups, but in the last 20 years that there have been both of those, no one has compared either to the other. Both have been found to be better than the standard American diet, but just about anything is
I think the problem is there’s religious need behind the effort to make meat look dangerous so more people go vegetarian, but there’s no organisation behind the meat eaters