Vegan Diet

Understand

Overview

A vegan diet excludes all animal products — meat, fish, eggs, dairy and honey — building the diet entirely around vegetables, fruit, legumes, whole grains, nuts and seeds. It differs from vegetarianism, which usually allows dairy and eggs.

The scientific evidence comes mainly from large cohort studies (such as EPIC-Oxford) linking plant-based diets with lower cardiovascular disease risk and lower BMI, plus a smaller but concrete body of randomized trials — including Barnard's 2006 study, in which a low-fat vegan diet improved glycemic control in people with type 2 diabetes more effectively than standard dietary recommendations. This is a solid but narrower evidence base than for the Mediterranean or DASH diets, which rest on large interventional trials.

Who can this realistically help, and who probably shouldn't bother? People with elevated cardiovascular or metabolic risk who are willing to plan meals deliberately can see measurable improvements in their lipid profile. Ethical or environmental motivation is an equally valid reason to choose this diet, independent of any health benefits. Children, pregnant and breastfeeding women, and competitive athletes should exercise the greatest caution — not because a vegan diet is contraindicated for them, but because covering the increased need for protein, iron, zinc and vitamin B12 in these groups requires especially careful planning, ideally with a dietitian.

History of use

The term "vegan" was coined in 1944 by Donald Watson, co-founder of the UK's Vegan Society, to describe a diet and lifestyle excluding all animal products — as distinct from vegetarianism, which allows dairy and eggs. Scientific interest in plant-based diets as a health intervention intensified from the 1990s onward, driven in part by Dean Ornish's work on reversing atherosclerotic changes and by large cohort studies such as EPIC-Oxford, which has tracked the health of vegans, vegetarians and meat-eaters for decades.