Quick answer: Eating more plant foods is a healthy choice with arthritis, and fits the Mediterranean-style pattern NICE suggests for rheumatoid arthritis. A few small trials suggest vegan or vegetarian diets may help some people with rheumatoid arthritis, but a Cochrane review found the effects uncertain. If you go fully vegan, plan for vitamin B12, iodine, calcium, vitamin D, omega-3 and protein, and consider seeing a dietitian.
Evidence checked on 10 October 2026 against a Cochrane review of dietary interventions for rheumatoid arthritis, NICE NG100, the NHS vegan diet guide and the BDA plant-based food fact sheet.
Vegan and plant-based diets are often presented online as a way to "reverse" arthritis. Some people with arthritis say that going plant-based has helped them a lot, while others notice no change. This review explains what the research really shows, what the clear benefits of eating more plants are, and how to make sure a plant-based diet gives you everything you need.
What do the terms mean?
| Term | What it usually means |
|---|---|
| Plant-based | Based mostly on plant foods (vegetables, fruit, wholegrains, beans, nuts and seeds), with few or no animal foods. The BDA uses this broad definition |
| Vegetarian | No meat or fish; usually includes dairy and eggs |
| Vegan | No animal foods at all, including dairy, eggs and honey |
| Flexitarian | Mainly plant-based, with occasional meat or fish |
| Mediterranean | Plant-rich, with fish, olive oil and moderate dairy and poultry |
"Plant-based" does not automatically mean healthy. Chips, crisps, biscuits and many processed vegan products are plant-based but high in salt, sugar or fat. The benefits come from whole or minimally processed plant foods.
What the evidence shows
The Cochrane review
A Cochrane systematic review of dietary interventions for rheumatoid arthritis (Hagen and colleagues, 2009) included vegetarian and vegan diets, as well as Mediterranean, elemental and elimination diets. It concluded that the effects of these diets on rheumatoid arthritis are still uncertain, because the studies were small, single trials with a moderate to high risk of bias. It also noted higher drop-out rates and weight loss in the diet groups, and said potential adverse effects should not be ignored.
Fasting followed by a vegetarian diet
The best-known research comes from Norway. A summary by the lead researcher (Kjeldsen-Kragh, 1999) described trials in which people with rheumatoid arthritis fasted for a short period and then followed a vegetarian diet for a year. Some people improved, and improvements were greater in those who responded to the diet than in non-responders and people who continued to eat meat. The author concluded that some patients with rheumatoid arthritis can benefit from this approach. This is promising but involved a small number of people, a supervised fasting period that is not suitable for many people, and results that varied a lot between individuals.
A more recent vegan diet trial
A randomised crossover trial published in 2022 (Barnard and colleagues) gave 44 adults with rheumatoid arthritis a vegan diet for four weeks, followed by an elimination and reintroduction phase, and compared this with a placebo supplement phase. Disease activity scores and swollen joint counts improved more during the diet phase. However, the trial was small, the diet was combined with elimination of other foods so it is hard to know which part mattered, some people changed medicines during the study, and the authors were linked to an organisation that promotes plant-based diets. When the analysis was limited to people who made no medicine changes, the difference between phases was no longer statistically significant.
Osteoarthritis
There is very little direct trial evidence on vegan or vegetarian diets for osteoarthritis. For osteoarthritis, the clearest diet-related benefit comes from losing excess weight, which NICE guidance (NG226) says improves pain and function. A plant-rich diet high in fibre can help with that.
What NICE says
NICE guidance on rheumatoid arthritis (NG100) says there is no strong evidence that changing your diet will benefit your arthritis, but people could be encouraged to follow Mediterranean diet principles: more bread, fruit, vegetables and fish, less meat, and plant-oil-based products in place of butter and cheese. That is a plant-forward diet, but not necessarily a vegan one. Our Mediterranean diet guide explains how to follow it.
Evidence at a glance
| Question | Honest answer |
|---|---|
| Can a vegan diet cure arthritis? | No. There is no evidence that any diet cures arthritis |
| Can it help rheumatoid arthritis symptoms? | Possibly for some people. Small trials are encouraging, but the evidence is uncertain |
| Does it help osteoarthritis? | Little direct evidence. It may help indirectly through weight management |
| Is eating more plants healthy? | Yes. More fibre, fruit, vegetables and pulses are good for heart health and weight |
| Do I need to go fully vegan? | No. A Mediterranean or flexitarian pattern gives many of the same benefits |
The real benefits of eating more plants
- Fibre. Most UK adults eat about 20g of fibre a day, and the NHS says this should increase to 30g. Beans, lentils, wholegrains, fruit and vegetables are the main sources. Fibre also feeds the bacteria in your gut; see our gut health guide.
- Heart health. Inflammatory arthritis is linked with a higher risk of heart disease. Diets lower in saturated fat and higher in plant foods support heart health, as part of an anti-inflammatory eating pattern.
- Weight. Plant-rich meals tend to be filling and lower in energy, which helps with weight management.
- Cost. Beans, lentils, oats, frozen vegetables and seasonal fruit are among the cheapest foods in UK shops.
Nutrients to plan for
The NHS says you can get the nutrients you need from a varied and balanced vegan diet, including fortified foods and supplements. But if you do not plan, you could miss out on calcium, iron, vitamin B12, iodine and selenium. Some of these matter especially with arthritis.
| Nutrient | Why it matters | Plant sources and tips |
|---|---|---|
| Vitamin B12 | Healthy blood and nerves. The BDA says it is not available from plants | Fortified breakfast cereals, fortified soya drinks, yeast extract and fortified nutritional yeast. A supplement may be needed |
| Calcium | Bone health, especially if you take steroids or have osteoporosis risk | Fortified unsweetened soya, pea or oat drinks, calcium-set tofu, broccoli, cabbage, okra, and bread (calcium is added to white and brown flour in the UK by law). The NHS notes the body cannot absorb all the calcium in spinach |
| Vitamin D | Bones and muscles | Fortified spreads, cereals and soya drinks. Everyone should consider a supplement in autumn and winter; check it is not animal-derived |
| Iodine | Thyroid function | Some plant drinks are fortified; check labels. Ask a pharmacist or dietitian before using seaweed or iodine supplements |
| Iron | Red blood cells; anaemia is common in inflammatory arthritis | Beans, lentils, dried fruit, dark green vegetables, fortified cereals. The NHS suggests eating vitamin C-rich food at the same time and avoiding tea or coffee with meals |
| Omega-3 | Heart health; fish oil has some evidence in rheumatoid arthritis | Walnuts, ground flaxseed, chia seeds, rapeseed oil; algae-based supplements contain EPA and DHA |
| Protein | Muscle to support joints | Beans, lentils, tofu, soya drinks, nuts, seeds and grains across the day. See our protein guide |
A note on processed vegan products
Supermarkets now sell a wide range of vegan burgers, sausages, cheeses, ready meals and snacks. Some are useful, convenient sources of protein, especially fortified ones. Others are high in salt, saturated fat (for example from coconut oil in vegan cheese) or sugar. The NHS advises adults to have no more than 6g of salt a day. Check the traffic-light labels, and base most meals on beans, lentils, tofu, wholegrains, vegetables and fruit rather than on highly processed alternatives.
A simple plant-based shopping basket
- Tins: chickpeas, kidney beans, baked beans (reduced sugar and salt), lentils, chopped tomatoes
- Dry goods: porridge oats, wholewheat pasta, brown rice, red lentils, wholemeal bread
- Freezer: mixed vegetables, spinach, peas, berries, edamame
- Fridge: calcium-set tofu, hummus, fortified unsweetened soya drink and yoghurt
- Cupboard extras: walnuts, ground flaxseed, peanut butter, rapeseed oil, yeast extract
Medicines and blood tests
- Methotrexate: if you take a B-vitamin or multivitamin supplement, check it does not contain folic acid if you are already prescribed folic acid, as the NHS advises.
- Warfarin: a big increase in green leafy vegetables can affect how warfarin works because of vitamin K. The NHS advises talking to your doctor before making big changes to your diet.
- Weight loss: if you lose weight quickly, tell your rheumatology team, as some doses depend on weight and unexplained weight loss needs checking.
- Blood tests: anaemia and low B12 can cause tiredness that is easily blamed on arthritis. Your GP can check these.
How to start: a step-by-step approach
- Start with additions, not restrictions. Add a portion of beans, lentils or vegetables to meals you already eat.
- Try a few meat-free days a week. Chilli with beans, lentil bolognese, vegetable curry or bean and vegetable soup.
- Swap some dairy if you wish, choosing calcium-fortified, unsweetened plant drinks and yoghurts.
- Keep it simple when joints hurt. Tinned beans and lentils, frozen vegetables, microwave grains and ready-to-eat tofu need little preparation.
- Plan the key nutrients in the table above, particularly B12, calcium, vitamin D and iodine if you go fully vegan.
- Keep a symptom diary for a few months so you can judge honestly whether it helps your joints.
- Do not stop prescribed treatment. Even if you feel better, talk to your rheumatology team before changing medicines.
A sample plant-based day
| Meal | Example |
|---|---|
| Breakfast | Porridge made with fortified soya drink, topped with berries and ground flaxseed |
| Lunch | Lentil and vegetable soup with wholemeal bread and hummus |
| Snack | Fortified soya yoghurt with walnuts, or an apple and a small handful of nuts |
| Evening meal | Tofu and vegetable stir-fry with brown rice, or chickpea curry with spinach and tinned tomatoes |
This is an example only. Portion sizes and the right balance depend on your needs. A registered dietitian can help, especially if you have other health conditions.
Possible downsides
- Unplanned weight loss, which the Cochrane review flagged as a possible adverse effect. This matters if you are already underweight or frail.
- Low B12, iron, calcium or iodine if the diet is not planned.
- Wind and bloating when fibre increases quickly. Increase gradually and drink plenty of fluids.
- Feeling guilty or anxious about food. Very strict rules can be stressful and hard to stick to. A flexible approach is fine.
When to see a dietitian
Ask your GP or rheumatology team about a referral to a registered dietitian if you plan to go fully vegan, are underweight, have lost weight without trying, take warfarin, have kidney disease, diabetes, coeliac disease or gout, or are pregnant or planning a pregnancy.
When to get medical help
See your GP if you feel very tired, short of breath, dizzy or notice pins and needles, as these can be signs of anaemia or low B12. See your GP if you lose weight without trying. Do not stop or change prescribed arthritis medicines because of a diet change. Get same-day advice from your GP or NHS 111 if a joint suddenly becomes hot, swollen and very painful, especially with a fever.
Frequently asked questions
Can a vegan diet help rheumatoid arthritis?
A few small trials suggest it may help some people, but a Cochrane review found the effects uncertain because the studies were small and at risk of bias. It should not replace your medicines.
Is a plant-based diet good for osteoarthritis?
There is little direct evidence. It may help indirectly by supporting a healthy weight, which NICE says improves osteoarthritis pain and function.
Do I need to cut out all animal foods?
No. NICE suggests Mediterranean diet principles for rheumatoid arthritis, which include fish and some dairy. Eating more plants and less meat gives many of the benefits.
What supplements do vegans need?
Vitamin B12 is essential, as it is not available from plants. Many vegans also need vitamin D, and may need iodine and calcium depending on what they eat. A pharmacist or dietitian can advise.
Will a plant-based diet affect my arthritis medicines?
Most medicines are not affected, but big changes in green leafy vegetables can affect warfarin, and some supplements contain folic acid, which matters with methotrexate. Tell your team about diet changes.
How long should I try a plant-based diet to see if it helps?
The trials ran for several months. If you want to test it, keep a symptom diary for at least two to three months, and discuss the results with your rheumatology team.
Sources and further reading
- Hagen KB et al. Dietary interventions for rheumatoid arthritis. Cochrane Database Syst Rev 2009 (PMID 19160281)
- Kjeldsen-Kragh J. Rheumatoid arthritis treated with vegetarian diets. Am J Clin Nutr 1999 (PMID 10479237)
- Barnard ND et al. A randomized, crossover trial of a nutritional intervention for rheumatoid arthritis. Am J Lifestyle Med 2022 (PMID 39981557)
- NICE NG100: Rheumatoid arthritis in adults – recommendation 1.8.8 (diet)
- NHS: The vegan diet
- BDA: Vegetarian, vegan and plant-based diet food fact sheet
- Arthritis UK: Eating well with arthritis
Educational information for people in the United Kingdom — not personal medical or dietary advice. Food and supplements can interact with medicines, so check with your GP, pharmacist or rheumatology team before changing your diet significantly or starting a supplement, and ask for a referral to a registered dietitian for individual advice. Charity no. 1218461. Pending clinical and editorial review. If you feel very unwell, call 999 or go to A&E. For urgent advice, contact NHS 111.
Continue with related help
- Anti-inflammatory diet guide — the evidence-based pattern
- Mediterranean diet — plant-rich, with fish
- Protein requirements — getting enough on any diet
- Gut health and arthritis — fibre and the microbiome
- Arthritis diet myths — claims that do not stand up