The great apes, of whom homo sapiens is one, are closely related genetically. Nevertheless we are the odd man out in that we cook food and eat meat while our cousins are high fiber vegetarians with the exception of the chimpanzees for whom meat may form part of their diet. We therefore fed healthy volunteers three diets for two weeks each where all the food was provided. One was a standard low fat therapeutic diet, another was an early agricultural diet and the third was the Simian diet v high in fruit and veg plus some nuts. All diets were vegetarian the last was vegan and was meant to represent what our ancestors 4 million years ago. To our surprise the simian diet dropped LDL cholesterol by ~ 35%. We have subsequently designed diets that are more manageable in terms of food volume. Our cholesterol lowering diet or dietary portfolio including nuts, vegetable protein from soy and beans, sticky fibers from oats, barley and psyllium, and a plant sterol enriched margarine also lowers LDL cholesterol by 30%, like a cholesterol lowering statin drug. Our data support the value of plant foods for health. Such eating habits that are plant based have a major impact in preventing the creation of greenhouse gases, and the destruction of rain forest homes of other species. The major agencies concerned with health are now also promoting more plant based diets. The message is that we must act now. From a planetary perspective it may already be too late.