The recommendations
As for the recommendations themselves, we wanted to start off by emphasizing weight loss and what can be called weight-loss support. There’s a link between obesity and the risk of developing rheumatoid arthritis, and also psoriatic arthropathy. And the more overweight a patient is, the more active their disease. In other words, patients with obesity are going to experience more pain, more instances of wakefulness, and more morning stiffness than their normal-weight peers. They’re also going to show symptoms that suggest that disease activity is not controlled well.
Several randomized controlled studies have shown that weight loss will improve systemic joint symptoms. In one particular study, patients with psoriatic arthropathy were started on [tumor necrosis factor] inhibitor therapy and one group followed a prescribed diet and the other had no restrictions on eating. More patients in the diet group than in the no-diet group achieved minimal disease activity. Of course, in some cases – for example, patients with complicated morbid obesity – it might be necessary to have a discussion about bariatric surgery.
But practically speaking, how does one proceed? First of all, patients should be weighed at each visit and, if they’re overweight or obese, the subject should be broached. But even after that conversation, the reality remains that it’s not easy to lose weight. So in the recommendations, we focused on the fact that it shouldn’t be left to the rheumatologist or treating physician alone to handle this challenging aspect of treatment. They should incorporate dietary and nutritional care by reaching out to a dietician or, in the case of complicated obesity – especially when the BMI is higher than 35 kg/m2 – they can refer patients to a nutrition expert who can manage the patient’s obesity, come up with a weight-loss plan, and handle any complications that might arise.
We don’t speak about a low-calorie diet in the recommendations because a diet has a beginning and an end and, quite often, patients regain weight after stopping a diet. Instead, we speak about weight-loss support to point out that weight loss maintained through dietary changes brings about long-term control of disease activity.
In addition, we make two positive recommendations, which overlap, that can help patients control their disease: a Mediterranean diet and omega-3 supplements. One study showed that after participants with rheumatoid arthritis followed the Mediterranean diet for 1 year, those who also took omega-3 fish oil supplements were twice as likely to achieve remission (40% vs. 20%). This explains the interest in having omega-3 as part of the diet. Other studies have shown a broad benefit of the Mediterranean diet.
We know this diet: Fish, especially fatty fish; meat, but not every day, and white meat is best; and fruits and vegetables. In addition, exercise and stay hydrated. All of this can help patients who want to use diet as a means to control their disease. And, as I said earlier, studies have shown that omega-3 supplements have beneficial effects. These are essential polyunsaturated fatty acids, which can help control the disease and joint symptoms.
We also provide some exclusionary recommendations. Not all studies are done well, but it’s clear that there are no major benefits – in fact, no benefit at all – from vegan diets, gluten-free diets, or dairy-free diets. And with these diets, patients run the risk of developing deficiencies, so it’s important that patients are aware of this. We also have to keep in mind that exclusion diets can increase social isolation. Patients need to take part in meals; such gatherings are times for sharing and having social interactions. And I would say that they must be told that there are no data in the literature in support of these diets. But if they ever insist on this kind of intervention, I think that it’s better to advise them to do it under the supervision of a dietician and nutritionist, especially to prevent the development of deficiencies. We’re talking about deficiencies in things like calcium, vitamin B12, and selenium.
Conclusion
As you can see, we have positive recommendations when the patient wants to do something beyond pharmacologic treatment: the Mediterranean diet and omega-3 supplements. And we have negative recommendations, marked by a warning about the risk of developing deficiencies. But I think we all understand the importance of paying close attention to how our patients are experimenting with food. Their diets and eating habits can give us ideas for research and reviews that could allow us to deepen our understanding of the effect of diet on disease, because currently, the quality of the data on some of the diets and types of dietary interventions out there is rather tenuous.
Thank you for listening. I’d also like to thank Claire Daien, MD, PhD, for conducting this project with me so that we could come up with all of these recommendations. I’m also grateful to the following nutrition societies and associations who were our partners: the French Society of Nutrition, the French-Speaking Society of Clinical Nutrition and Metabolism, the French Association for the Study of Obesity, and the French Association of Dieticians and Nutritionists. And patient associations, too, must be recognized, as some of their members participated: the French National Association Against Rheumatoid Arthritis, the French Spondyloarthritis Association, and the French Association for Polyarthritis and Chronic Inflammatory Rheumatic Diseases.