Arthritis is the inflammation of joints. It causes joint pain and stiffness which usually worsens with age. The most common types of arthritis are osteoarthritis and rheumatoid arthritis.

Osteoarthritis causes the cartilage that covers joint surfaces to break down. Rheumatoid arthritis (RA) is an autoimmune disorder causing the immune system to attack the lining of joints and degrade it.

A vegan diet has been shown to be able to improve the health of RA sufferers and reduce the pain and stiffness of joints. Research revealed that people suffering from RA have inflammation of the intestinal tract resulting in increased permeability of the gut wall. With increased intestinal permeability, foreign proteins from foods and bacteria can pass into the bloodstream and cause an immune reaction that can harm joint lining. Fasting is known to decrease intestinal permeability and improve the symptoms of patients with RA but when patients return to a diet with dairy products the gut becomes more permeable and the arthritis returns (McDougall, 2002).

Several research teams have studied the impact of fasting followed by a vegan or vegetarian diet on patients with RA. Kjeldsen-Kragh’s trial (1999) was the biggest one and it tested the effect of fasting for seven to 10 days, followed by three and a half months of an individually adjusted gluten-free vegan diet and for the next nine months consuming an individually adjusted vegetarian diet. Compared to the control group of RA patients who didn’t change their diet, the diet change group improved significantly. The level of improvement varied but based on the results, a vegan diet was recommended as a part of RA treatment. Müller et al. (2001) reviewed all available studies with a similar design and reached the conclusion that a vegan diet is more effective than vegetarian.

Hänninen et al. (2000) and Nenonen et al. (1998) studied the effects of a raw vegan diet on people with RA. These people volunteered to follow a diet of berries, fruits, vegetables and roots, nuts, germinated seeds and sprouts for three months. Their intake of antioxidants, fibre and health-protective phytochemicals increased significantly.  In both studies, the rheumatoid patients who followed the diet for at least two months reported significant alleviation of their symptoms (joint pain, stiffness, swelling) but once they returned back to their omnivorous diet, the symptoms got worse.

Apart from the high intake of nutrients helping to improve health and decrease inflammation, the diets in the studies above also led to dramatic positive changes in the intestinal bacteria (Hänninen et al., 2000; Kjeldsen-Kragh, 1999; Peltonen et al., 1997). The bacteria species that thrive on plant-based foods are those that can significantly reduce inflammation and therefore the symptoms of arthritis. On the other hand, bacteria promoted by meat-based and fatty diets can increase the inflammation through toxic by-products of their metabolism. The study authors remarked that the greater the change in the gut microflora was, the better the patients’ health was.

A recent review (Lahiri et al., 2012) agreed that an antioxidant-rich diet can improve arthritis symptoms and can also help prevent the condition from developing. However, it’s the overall diet that matters and the study highlighted that fruit and vegetable consumption is more important than supplements.

Hafström et al. (2001) tested the effects of a gluten-free vegan diet in an effort to eliminate gluten as a potential irritant. They assigned a group of RA sufferers to a diet consisting of fruit and vegetables, nuts, seeds and grains such as buckwheat, millet, corn and rice for one year and followed them throughout. Compared to the control group (who were following their usual, omnivorous diet), patients on the vegan diet achieved improvement in all clinical symptoms. The patients also had regular blood tests and in the vegan group, the levels of antibodies involved in the immune response to food irritants significantly decreased. This can be an important factor in decreasing joint inflammation. 

Because dietary modifications have long been known to improve arthritis but fasting, gluten-free or a raw diet is not always possible or sustainable in the long term, Dr McDougall’s team set out to test what they deemed to be an effective, inexpensive and practical dietary approach – a low-fat vegan diet (McDougall et al., 2002). Plant-based foods consistently prove to be beneficial for people with arthritis but fats are known to have a negative effect so the diet had to be low in fat. They enlisted rheumatoid arthritis sufferers with moderate to severe degree of the illness who previously didn’t follow a vegan or dairy-free diet. These patients were prescribed a wholesome, low-fat vegan diet for four weeks (based on pulses, wholegrains, fruit and vegetables). At the end of the test period, the participants lost on average three kilograms and their symptoms dramatically improved: pain and limitation in ability to function decreased and joint tenderness, swelling and severity of morning stiffness also decreased. Patients with the most active form of disease experienced the biggest improvements while patients with long-standing disease that had already destroyed most of the joint tissues experienced smaller improvements.

People with rheumatoid arthritis have an increased risk of cardiovascular disease. The fat levels in their blood tend to be higher and they have higher levels of cholesterol and LDL (‘bad’) cholesterol – both these patterns are related to inflammation. Elkan et al. (2008) focused on these issues when they tested the long-term effects (one year) of a gluten-free vegan diet as a dietary treatment for RA. The vegan group patients not only improved in terms of RA symptoms but their cholesterol levels improved and they lost weight – both these results are very desirable and are known to be important in the prevention of cardiovascular disease.  

Overall, the research is very supportive of a vegan diet as a part of RA treatment. Some people react better to a gluten-free vegan diet but the exclusion of animal derived foods seems to be more important. McDougall team’s model of a low-fat wholesome vegan diet for RA sufferers (McDougall et al., 2002) was very efficient in terms of health and symptom improvement and is affordable and sustainable in the long term for everyone.

Case study: Emma Bradley, Redditch

I have suffered from two main health problems during my life, rheumatoid arthritis and being overweight. The first, rheumatoid arthritis was diagnosed at just 18 months. I have spent much of my life taking drugs, attending physiotherapy and hydrotherapy just to stay mobile. During 'flare-up' periods I needed help even to get out of bed and yet at quiet periods I was able to walk reasonable distances and even take part in aerobics classes.

My other health problem was being overweight, this was partially due to restrictions in mobility but also poor nutrition. I became a vegetarian aged thirteen but replaced meat with cheese. Later on in my life, having my daughter made me really 'look' at our diet and change it to include plenty of fruit and vegetables. Going vegan was not as difficult as we thought it would be. We learnt to cook new things and found replacements for our favourite foods. A major benefit for me and totally unexpected has been the considerable reduction in pain from my arthritis, so much so that I no longer need any medication. It's fantastic but I can't help but feel annoyed that despite all medical evidence no doctor or specialist ever passed this information on to either myself or my parents. I had a happy childhood but there were things I missed out on - climbing trees, riding a bike - and I'm left with deformed joints. I can't help but wonder, would it have been a different story if I'd stopped having dairy as a child?

For references and more information, see The Incredible Vegan Health report. Or visit Nutrition News for latest studies on diet and health.