A vegan diet can significantly lower your risk of heart disease and type 2 diabetes, and it carries a fraction of the environmental footprint of a meat-heavy diet. Those are the two big categories of reasons people go vegan: personal health and the planet. How much each one matters to you is personal, but the data behind both is substantial.
Heart Disease and Cardiovascular Risk
People who eat the most plant-based foods have a 16% lower risk of developing cardiovascular disease compared to those who eat the least, after adjusting for factors like smoking, exercise, and alcohol. The gap widens when you look at dying from heart disease specifically: those with the highest plant-based diet adherence had a 31% to 32% lower risk of cardiovascular mortality. A large study published in the Journal of the American Heart Association tracked middle-aged adults over time and found these reductions held up even after accounting for other lifestyle differences.
The mechanisms are straightforward. Plant-based diets tend to be lower in saturated fat and cholesterol, which keeps blood pressure and LDL cholesterol in check. They’re also higher in fiber, potassium, and antioxidants, all of which support healthy blood vessels. You don’t need to be perfectly vegan to see benefits, but the more consistently plant-based your eating pattern, the stronger the association with lower cardiovascular risk.
Type 2 Diabetes Prevention
The diabetes data is striking. In a long-term cohort study, the prevalence of type 2 diabetes was 49% lower among vegans and 46% lower among lacto-ovo vegetarians compared to non-vegetarians. That’s roughly half the rate of diabetes in people who avoid animal products entirely.
This makes sense biologically. Plant-based diets improve insulin sensitivity, partly because they tend to be lower in calories and higher in fiber, which slows sugar absorption. People eating vegan also tend to carry less body fat, and excess body fat is the single biggest modifiable risk factor for type 2 diabetes. If you have a family history of diabetes or you’ve been told your blood sugar is trending upward, shifting toward plant-based eating is one of the most effective dietary changes you can make.
The Climate and Land Use Case
A vegan diet produces about 75% less heat-trapping gas than a meat-rich diet, defined as one that includes at least 100 grams of meat per day (roughly one steak the size of a deck of cards). Put another way, a plant-based diet has one-fourth the climate impact of a high-meat diet. That’s a massive difference from a single lifestyle change, and it’s one reason environmental organizations increasingly point to food choices as a meaningful lever for individuals.
The land use math is even more dramatic. Livestock accounts for 80% of all agricultural land when you combine grazing land and cropland used to grow animal feed. Yet meat, dairy, and farmed fish provide only 17% of the world’s calories and 38% of its protein. That’s an enormous amount of land dedicated to a relatively small share of our food supply. If more people shifted toward plant-based eating, vast areas of land currently used for grazing or feed crops could be restored to forest or wild habitat, which would absorb carbon and support biodiversity.
Water Use and Resource Efficiency
Producing one pound of beef requires about 1,850 gallons of water. One pound of soybeans requires about 283 gallons, and soybeans actually deliver more protein per pound (163 grams versus 118 grams for beef). That means beef uses roughly six and a half times more water per pound and still provides less protein. Pulses, lentils, and other plant proteins follow a similar pattern: dramatically lower water requirements for equal or greater nutritional output.
In a world where freshwater scarcity is a growing concern in many regions, the water efficiency of plant protein is a practical argument that goes beyond personal health. Every meal you shift from animal to plant protein frees up water for other uses.
What About Longevity?
This is where the picture gets more nuanced. While the heart disease and diabetes benefits are well-established, the evidence on whether vegans live longer overall is mixed. A large prospective study tracking over 117,000 participants in a National Cancer Institute cohort found no statistically significant difference in all-cause mortality between vegans and omnivores. Pesco-vegetarians (people who eat fish but no other meat) showed the most favorable trend, with a 19% lower mortality risk, though even that didn’t reach statistical significance.
This doesn’t mean a vegan diet is unhealthy. It means that when it comes to total lifespan, the advantage of going fully vegan over a generally healthy omnivorous diet isn’t clearly established. You can eat poorly as a vegan (processed foods, refined carbohydrates, low nutrient density) just as easily as you can eat poorly as an omnivore. The quality of your overall diet matters more than the label you put on it.
Nutrients to Plan For
Vitamin B12 is the one nutrient you genuinely cannot get from a fully plant-based diet without supplementation or fortified foods. Adults need 2.4 micrograms per day, and older adults may need 10 to 12 micrograms to absorb enough. B12 deficiency can cause fatigue, nerve damage, and cognitive problems over time, so this isn’t optional. A daily supplement or regular consumption of B12-fortified foods like plant milks, nutritional yeast, or fortified cereals covers it easily.
Beyond B12, the nutrients that require some attention on a vegan diet include iron, zinc, calcium, omega-3 fatty acids, and vitamin D. None of these are impossible to get from plants, but they take more deliberate planning than on an omnivorous diet. Dark leafy greens, fortified plant milks, seeds, nuts, and legumes cover most of the gaps. Pairing iron-rich foods with vitamin C (like spinach with lemon juice) improves absorption significantly. Algae-based omega-3 supplements provide the same long-chain fatty acids found in fish oil.
Ethical Considerations
For many vegans, the primary motivation isn’t health or the environment but a moral objection to using animals for food. Modern animal agriculture involves practices that most people would find uncomfortable if they saw them firsthand: intensive confinement, separation of mothers and offspring, and slaughter at a fraction of the animal’s natural lifespan. Whether this constitutes a sufficient reason to change your diet depends on your personal ethical framework, but it’s the reason veganism is a philosophy for many people rather than just a dietary pattern.
This distinction matters because it shapes how sustainable the change is for you. People who go vegan for ethical reasons tend to stick with it longer than those motivated purely by health, possibly because the moral commitment provides a stronger anchor when convenience pulls in the other direction.
Making It Work Practically
The most common reason people quit a vegan diet isn’t nutrient deficiency or health problems. It’s inconvenience. Eating out, traveling, attending social events, and cooking for mixed households all become more complicated. Planning ahead makes the difference: learning a rotation of 10 to 15 meals you enjoy, identifying vegan-friendly restaurants in your area, and keeping staples like canned beans, frozen vegetables, tofu, and whole grains stocked at home.
You also don’t have to go fully vegan overnight to capture most of the benefits. The cardiovascular research shows a dose-response relationship: the more plant-based your diet, the lower your risk. Replacing even a few meat-based meals per week with plant-based alternatives moves the needle on both your health markers and your environmental footprint. Some people find that starting with a few vegan days per week builds the skills and habits that make a full transition feel natural over time.