A Unique Study Design Looked at Rheumatoid Arthritis Symptoms and Food
While previous studies have already found positive connections between plant-based, anti-inflammatory diets and reduction of RA joint pain, this study differs in that it also included a crossover section, in which the diet participants and the placebo group (which believed it was getting special supplements) switched places after the first trial run was completed.
An Elimination Diet Systemically Removes, Reintroduces Suspect Foods
A vegan diet is the strictest form of a vegetarian diet. In addition to limiting meat, vegans refrain from eating all animal products. After four weeks on a vegan diet, the diet groups took another dramatic step — an elimination diet. Participants also individually eliminated known trigger foods, such as gluten-containing grains, soy products, white potatoes, sweet potatoes, chocolate, citrus, fruit, nuts, peanuts, onions, coffee, alcohol, and sugar. After three weeks on a combination vegan and elimination diet, participants reintroduced the potential trigger foods one by one over nine weeks to see specific foods were problematic. If a certain food caused joint pain, it was eliminated again. If the food didn’t cause them any problems, they kept it in their diet. “Diet is a very important part of treating an inflammatory condition like RA. If you can control the diet, it makes sense that the patients would have less inflammation. If you are already on a vegan or vegetarian diet and then also eliminate your trigger foods, you have an even better chance of improvement,” says Nilanjana Bose, MD, rheumatologist at Lonestar Rheumatology in Houston, who was not part of the study.
A Plant-Based Diet Reduces Pro-Inflammatory Foods, Increases Anti-inflammatory Foods
Two factors appear to be at work in the vegan diet that facilitates symptom reduction. “One is, when you go with a plant-based, vegetarian, or vegan diet, you have a lower saturated fat intake. You’re not eating animal fats, or adding butter, cheese, and milk fat. When you take out those saturated fats, that can be pro-inflammatory, and replace them with plant-based fats from things like nuts and seeds, you have healthier types of fats in general, that are less inflammatory, or even anti-inflammatory,” says Lona Sandon, PhD, RDN, associate professor and program director for the department of clinical nutrition in the School of Health Professions at the University of Texas Southwestern Medical Center in Dallas. “The other possibility is when you eat a plant-based diet, you’re getting more of the phytochemicals from plants that are also anti-inflammatory,” she says. “It’s not just vitamin D and vitamin C but all these smaller plant compounds, such as anthocyanin, that have some impact in the body in terms of inflammation.”
More Research Is Needed
There are drawbacks to this study, which merits further research. The study included a fairly small sampling: only 44 people with rheumatoid arthritis, some of whom did not follow the protocol. “While this is a decent, well-designed study, we need to take into account to what degree can you extrapolate these findings to a bigger population. I would also like to see some biomarkers added to the measurement, as opposed to more of clinical observation of disease activity. Clinical biomarkers [such as blood levels of proteins that indicate systemic inflammation] would help strengthen the studies and result,” cautions Landon, who has rheumatoid arthritis. Dr. Kahleova agrees that the research is an intriguing start: “This was basically a pilot study. While no study like this has ever been done before, more studies like this would be needed to confirm the findings in different populations and in bigger populations as well. We believe that other research groups may find it inspiring to start new studies along those lines.”
Vegan Diets Are Challenging to Follow Long-Term
Another drawback, says Dr. Sandon, is that a vegan diet is difficult to maintain. Many people just try it and give up. “If not approached correctly, many may end up with nutrient deficiencies. People with rheumatoid arthritis are already at risk for nutrient deficiencies; they don’t need to put themselves at greater risk. They need adequate protein. They need adequate vitamins and minerals.” Dr. Bose suggests, “We tell our patients wishing to go vegan to take it step by step, especially if they were not previously vegetarian. First, cut out the red meat, and then all meats and fish. Do it slowly, because going vegan can be a little overwhelming. If you can’t maintain it, try eating a vegetarian diet, because a diet you can stick to is better than one you can’t.” If you do wish to adopt a vegan diet, plan on where you will get your nutrients that you’re now giving up: protein, calcium, B vitamins, and iron. It is best to consult a registered dietitian (RD) or a registered dietitian-nutritionist (RDN) on how to create a balanced, healthy diet.
