Your gut produces a significant share of your body’s serotonin. If serotonin production shapes how you feel, and your gut produces most of it, then what you eat directly shapes your mood. This connection is one of the most practical reasons to move toward vegan or plant-based eating: not for ethics alone, not for the planet alone, but because you’ll likely feel better as a result. Your mental health is partly a direct result of what you feed your gut microbiome.
Here’s the difference between vegan and plant-based, the link between plant foods and mental health, and the practical foods that actually do the work.
Vegan vs plant-based: they aren’t the same thing
Plant-based describes your diet. Vegan describes your entire life. Someone eating a plant-based diet has removed or significantly reduced animal products from their meals. They eat plants, plant-based alternatives and plant-derived foods. Someone living vegan, as defined by The Vegan Society, seeks to exclude all forms of exploitation of animals for food, clothing or any other purpose, as far as is possible and practicable. Every choice aims to exclude animal exploitation and suffering.
Both can be healthy. Neither is inherently better than the other.
The distinction matters because if you’re moving toward veganism, you’re committing to more than food choices. You’re examining every purchase, every product, every decision through the lens of animal welfare. Your clothes, your toiletries, your household cleaners, your shoes. If you’re moving toward plant-based eating, you’re optimising your diet without necessarily changing everything else. You might eat plant-based but still wear leather, use wool, or use products with animal by-products. Both are valid approaches. Know which one you’re aiming for so your expectations match your commitment.
How your gut talks to your brain
The gut-brain axis is a two-way conversation between your digestive system and your central nervous system. Your gut microbiome (the bacteria, fungi and other microorganisms living in your digestive system) directly influences your brain chemistry. A 2015 review in Annals of Gastroenterology summarised the evidence that gut microbiota produce neurotransmitters including serotonin, GABA and dopamine, which communicate with the brain through the vagus nerve.
A significant share of your serotonin is produced in the gut. What you eat directly affects your mood.
Plant-based and vegetarian diets tend to create more stable, varied microbiota with a healthier population of beneficial bacteria. A 2019 study in Nature Microbiology led by researchers at KU Leuven identified specific bacterial species in the gut whose relative abundance correlated with self-reported quality of life, including markers of depression. Plant-based diets are typically higher in fibre, which feeds beneficial bacteria, which in turn produce short-chain fatty acids that support brain function. A 2020 meta-analysis in Neuroscience and Biobehavioral Reviews found that dietary patterns high in fruits, vegetables, wholegrains and legumes were associated with reduced risk of depressive symptoms across a large number of studies.
The effect isn’t small. It’s measurable. People report feeling better, sleeping better and managing stress more effectively.
This doesn’t mean plant-based eating is a cure for mental illness. It means it’s a foundational support for mental health. It works best alongside professional support, therapy and medical treatment when needed. As a baseline intervention, food is one of the more powerful tools you have.
The ‘junk food vegan’ trap
You can eat vegan and eat poorly. Processed vegan ice cream, sugary sweets, refined carbohydrates and ultra-processed alternatives don’t give your gut or your brain what they need. They satisfy cravings but not nutrition. They’re still vegan, but they’re not nourishing.
If you’re moving toward plant-based eating for your mental health, these don’t count. They won’t support your microbiome. They might taste good in the moment, but they leave you crashing later. Focus instead on whole foods: every colour of fruit and vegetable you can fit in, wholegrains, legumes, nuts, seeds and fermented foods. These do the actual work of feeding your microbiome and supporting serotonin production. The difference between vegan junk food and nourishing vegan food is the difference between restriction and genuine change.
What to eat
Start with vegetables. Dark leafy greens (spinach, kale, chard), broccoli, sweet potatoes, bell peppers, leafy herbs. These are nutrient-dense and full of fibre. The darker the green, the more nutrients it tends to contain.
Add fruit. Berries are particularly nutrient-dense, but eat what’s in season and what you enjoy. Apples, pears, bananas, oranges all support your microbiome.
Protein comes from beans, lentils, pulses, tofu, tempeh. These are rich in amino acids and fibre, inexpensive and versatile. Browse the Pulses edit for bulk options.
Healthy fats from avocado, nuts, seeds and olive oil support brain function and help nutrient absorption. Browse the Oils edit and the Nuts and Seeds edit.
Wholegrains. Oats, quinoa, brown rice, and wholewheat bread. Sustained energy and resistant starch that feeds your gut bacteria. Browse The Pantry range for staples.
Fermented foods. Sauerkraut, kimchi, tempeh, miso. These introduce beneficial bacteria directly into your digestive system. A 2021 randomised trial from Stanford University School of Medicine, published in Cell, found that a ten-week high-fermented-foods diet increased microbial diversity and reduced inflammatory markers. Browse the Fermented Foods edit.
Hydration matters more than people realise. Your brain needs water to function properly. The NHS recommends six to eight glasses of fluid a day, with water, lower-fat milks and sugar-free drinks contributing to the total. Dehydration affects mood, cognitive function and energy. Herbal teas count too.
Nutrients worth paying attention to on a vegan diet
The British Dietetic Association notes that well-planned vegan diets are healthful and nutritionally adequate, but they do require attention to several specific nutrients that are harder to get from plants alone.
Vitamin B12 is the most important. B12 is produced by bacteria and is found reliably only in animal products and fortified foods. Vegans need to either eat B12-fortified foods daily (fortified plant milks, nutritional yeast, some breakfast cereals) or take a supplement. Long-term B12 deficiency causes fatigue, nerve damage and cognitive issues, so this isn’t optional.
Vitamin D, iron, calcium, iodine and omega-3 fatty acids (specifically the long-chain DHA and EPA forms) also need attention. Vitamin D is harder to get in the UK through skin synthesis in winter and is worth supplementing October to March regardless of diet, per NHS guidance. Iron from plants (non-haem iron) is absorbed less efficiently than iron from meat, so pairing iron-rich foods with vitamin C helps. Algae-based supplements provide DHA and EPA without fish oil. Browse the Supplements edit for B12 and omega-3 options.
What your body also needs
Food is foundational, but not everything. Movement matters. The NHS recommends at least 150 minutes of moderate exercise a week. A 2023 umbrella review in the British Journal of Sports Medicine synthesising 97 meta-analyses found that regular physical activity produced reductions in symptoms of depression and anxiety comparable in magnitude to psychotherapy for many populations. Walking, cycling, swimming, dancing all count. Consistent movement matters more than intensity.
Time with people does work too. Connection matters to mental health. Fresh air and sunlight regulate your circadian rhythm and support vitamin D production. Journalling and meditation give your nervous system a chance to down-regulate. These aren’t optional add-ons. They’re essential components of wellbeing.
Plant-based eating is an accessible lever to pull, but it works best alongside everything else. Food, movement, connection, sleep and sunlight work together to create mental health. No single factor carries the whole burden.
For more on the specific food-mood link, read our how food affects mood guide, and our plant-based diet and mental health deep-dive.
Every brand in the Food and Drink category on Ziracle has passed the same standard: honest ingredients, transparent sourcing, and production that takes ethics seriously. For products that fit a vegan diet specifically, filter by Vegan or Organic.
Ready to start? Browse the Eat Well edit and pick one meal a day to shift toward whole, plant-based food.
FAQs
Plant-based describes what you eat: mostly or entirely plants, with animal products reduced or removed. Vegan describes a whole lifestyle: avoiding animal products in food, clothing, cosmetics, household items and anywhere else practicable, framed around excluding animal exploitation. Both can be healthy. The distinction matters for setting expectations. A plant-based eater might wear leather and use wool. A vegan won’t. Know which one you’re aiming for.
The evidence is moderately strong. A 2020 meta-analysis in Neuroscience and Biobehavioral Reviews found that dietary patterns high in fruits, vegetables, wholegrains and legumes (which describes well-constructed vegan and plant-based diets) were associated with reduced risk of depressive symptoms across many studies. The mechanism involves gut microbiome diversity, fibre intake and the fatty acids produced by beneficial bacteria. It’s not a cure for diagnosed mental illness, and it shouldn’t replace professional support. It is a foundational layer for everyday mental wellbeing.
Vitamin B12 is the most important. B12 is only reliably found in animal products and fortified foods, so vegans need either fortified foods daily or a supplement. The British Dietetic Association also flags vitamin D, iron, calcium, iodine and long-chain omega-3 fatty acids (DHA and EPA) as nutrients that need specific attention. Most of these can be covered with a well-planned diet plus a B12 supplement and a vitamin D supplement through UK winters, but it’s worth taking seriously rather than assuming the diet covers everything by default.
Nothing, if they’re occasional. The issue is relying on them as the bulk of a vegan diet. Ultra-processed vegan foods (sweet snacks, meat alternatives high in saturated fat and salt, refined carbohydrates) are still vegan but don’t deliver the microbiome or mental health benefits that come from whole plant foods. If you’re moving to vegan or plant-based eating partly for how you feel, the whole-food version is what does the work. Processed vegan junk food satisfies a craving but leaves the fibre, diversity and nutrient-density out.
Two to four weeks for most people, if the shift is toward whole foods rather than processed vegan alternatives. The Stanford fermented foods study measured meaningful microbial changes over ten weeks, but digestive differences and energy changes often appear earlier. Giving any dietary shift at least a month of consistency before judging it is the realistic approach. If you feel worse after two to three weeks, check that you’re getting enough protein, iron, B12 and calories, and consider a consultation with a dietitian.
