15 Vegan Myths Debunked by Science

Veganism has gone mainstream, but the myths haven't gone away. From "you can't get enough protein" to "soy gives you man boobs," these misconceptions persist despite overwhelming scientific evidence to the contrary. Here are 15 of the most common vegan myths — and the facts that debunk them.

Myth 1: Vegans don't get enough protein

This is the most persistent myth about veganism, and the most thoroughly debunked. The American Dietetic Association, the British Dietetic Association, and the Academy of Nutrition and Dietetics have all confirmed that well-planned vegan diets provide adequate protein for all stages of life, including pregnancy and athletic performance.

Lentils contain 9g of protein per 100g cooked. Tofu contains 10g. Tempeh contains 19g. Seitan contains 25g. A varied vegan diet easily meets the WHO recommendation of 0.83g of protein per kg of body weight. Most vegans in Western countries actually exceed their protein requirements — a 2019 EPIC-Oxford study found that UK vegans consumed an average of 13% more protein than the minimum recommendation.

Myth 2: Plant protein is inferior to animal protein

Plant proteins contain all essential amino acids. Some individual plant foods are lower in specific amino acids (lysine in grains, methionine in legumes), but eating a variety of plant foods throughout the day provides a complete amino acid profile. The outdated idea of "protein combining" at every meal was debunked by the American Dietetic Association in 2009 — your body pools amino acids over the course of a day. Soy, quinoa, buckwheat, hemp, and amaranth are complete proteins on their own.

Myth 3: Soy causes estrogen problems in men

Soy contains phytoestrogens (isoflavones), which are structurally similar to human estrogen but behave very differently in the body. A 2010 meta-analysis published inFertility and Sterility (Messina, 2010) analysed 15 placebo-controlled studies and concluded that neither soy protein nor isoflavones affect testosterone or estrogen levels in men. Asian populations have consumed soy for millennia with no evidence of feminising effects. The "soy boy" myth has zero scientific support.

Myth 4: B12 only comes from animal products

Vitamin B12 is produced by bacteria, not by animals. Animals get B12 from bacteria in soil and water — and most farmed animals are actually supplemented with B12 because modern farming practices have depleted these natural sources. When vegans take a B12 supplement, they're cutting out the middleman: getting the same bacterially-produced B12 directly. Fortified plant milks, nutritional yeast, and a simple weekly supplement (the NHS recommends 10 micrograms daily) fully cover B12 needs.

Myth 5: Vegan diets are expensive

A 2021 study published in The Lancet Planetary Health by researchers at Oxford University found that vegan diets were on average 30% cheaper than omnivorous diets in high-income countries when based on whole foods. The staples of a vegan diet — rice, beans, lentils, pasta, oats, potatoes, seasonal vegetables, and frozen produce — are among the cheapest foods available anywhere in the world. Vegan specialty products (plant-based burgers, vegan cheese) can be expensive, but they're optional luxuries, not necessities.

Myth 6: You can't build muscle on a vegan diet

Patrik Baboumian (World's Strongest Man competitor), Nimai Delgado (professional bodybuilder, vegan since birth), and Clarence Kennedy (Olympic weightlifter) all prove this wrong at the elite level. A 2021 systematic review in Sports Medicine found no significant difference in strength or muscle mass gains between plant-based and omnivorous diets when total protein intake was matched. The protein source does not matter — the total amount and training stimulus do.

Myth 7: Vegan diets don't provide enough calories

Plant foods span the entire caloric spectrum. Nuts and seeds are calorie-dense (almonds: 576 kcal/100g). Avocados provide 160 kcal per fruit. Grains, legumes, and starchy vegetables are calorie-rich. The idea that vegans are perpetually underfed comes from imagining a diet of only raw salads. In reality, many vegans struggle to not overeat — exactly like everyone else.

Myth 8: Vegans have weak bones

This myth comes from the association between dairy and calcium. But calcium is abundant in plant foods: kale (254mg per 100g cooked), fortified plant milk (typically 120mg per 100ml — the same as cow's milk), tofu set with calcium sulfate (350mg per 100g), tahini (426mg per 100g), and almonds (264mg per 100g). The EPIC-Oxford study found that vegans who consumed at least 525mg of calcium daily had no increased risk of bone fractures compared to omnivores. Vitamin D and weight-bearing exercise are equally important for bone health — and those are independent of diet.

Myth 9: Humans are designed to eat meat

Human anatomy is not clearly optimised for either a purely carnivorous or purely herbivorous diet. We are omnivores — meaning we can eat meat, not that wemust. Our long intestines, flat molars, and limited ability to synthesise vitamin C are more characteristic of herbivores than carnivores. The question is not whether humans evolved eating meat, but whether we need it now — and every major dietetic organisation in the world says we do not.

Appropriately planned vegetarian, including vegan, diets are healthful, nutritionally adequate, and may provide health benefits for the prevention and treatment of certain diseases. These diets are appropriate for all stages of the life cycle.

Myth 10: Vegan diets are nutritionally deficient

The only nutrient that requires supplementation on a well-planned vegan diet is B12 (and arguably vitamin D, but most omnivores are deficient in that too). Iron, zinc, omega-3, calcium, and iodine are all obtainable from plant sources with basic dietary awareness. Meanwhile, vegan diets tend to be higher in fibre, vitamin C, potassium, magnesium, and folate than omnivorous diets — nutrients that the majority of Western populations are deficient in.

Myth 11: Children can't thrive on vegan diets

The American Academy of Pediatrics, the British Dietetic Association, and the Canadian Paediatric Society all state that well-planned vegan diets can support healthy growth in children. The key word is "well-planned" — the same applies to omnivorous diets for children. A child eating chicken nuggets and chips every day is not well-planned either. Vegan children need adequate calories, B12, iron, calcium, zinc, and iodine — all of which are achievable with dietary awareness and supplementation where needed.

Myth 12: Vegan food is boring and tasteless

Indian cuisine — one of the most flavourful and complex in the world — has been largely vegetarian for centuries. Ethiopian, Thai, Japanese, and Middle Eastern cuisines all feature extensive plant-based traditions. The idea that removing meat from a dish makes it bland reflects a lack of culinary imagination, not a limitation of plant foods. Spices, herbs, fermentation, roasting, smoking, and umami-rich ingredients like miso, nutritional yeast, and mushrooms create depth and complexity that rivals any meat-based cuisine.

Myth 13: One person going vegan makes no difference

A 2023 study by researchers at Oxford University estimated that one person going vegan reduces their food-related carbon emissions by 75%, saves approximately 30 animal lives per year (based on average UK consumption), and reduces their land use footprint by 76%. Individually, these numbers are meaningful. Collectively — with over 80 million vegans worldwide and growing — the economic and environmental impact is enormous. Consumer demand drives supply: every plant-based meal purchased signals to producers, retailers, and restaurants.

Myth 14: Veganism is a first-world luxury

The cheapest diets in the world are already plant-based. Billions of people in Africa, South Asia, and Central America subsist primarily on rice, beans, lentils, maize, and vegetables — not because they're following a trend, but because these foods are affordable and available. It is animal products — particularly meat and dairy — that are the luxury items in most of the world. The framing of veganism as elite or privileged is a Western-centric perspective that ignores global dietary reality.

Myth 15: Crop farming kills more animals than livestock farming

This argument, sometimes called the "crop deaths" argument, claims that harvesting crops kills more field mice and insects than livestock farming. But it ignores a crucial fact: livestock eat crops. Roughly 36% of the world's crop calories are fed to livestock (Cassidy et al., 2013, Environmental Research Letters). A vegan world would require far fewer total crops, resulting in fewer total field deaths. A 2018 analysis by researchers at Oxford found that the total animal deaths (including field deaths) associated with a vegan diet were significantly lower than those associated with any diet containing animal products.