Diet May Help Reduce Inflammation in RA

Editor’s note: ACR on Air, the official podcast of the ACR, dives into topics important to the rheumatology community, such as the latest research, solutions for practice management issues, legislative policies, patient care and more. Twice a month, host Jonathan Hausmann, MD, a pediatric and adult rheumatologist in Boston, interviews healthcare professionals and clinicians on the rheumatology front lines. In a series for The Rheumatologist, we provide highlights from these relevant conversations. Listen to the podcast online at acronair.org, or download and subscribe to ACR on Air wherever you get your podcasts. Here we highlight episode 22, “The Impact of Diet on Rheumatic Conditions,” which aired on May 18, 2021.

People with rheumatoid arthritis (RA) often want to know if, or how, the foods they eat affect their disease. Yet many rheumatologists are not entirely sure how to answer this question. There’s not enough evidence and related studies are small, they say; or their own lack of education on diet and nutrition makes them feel uncertain.

During an episode of the ACR on Air podcast, Monica Guma, MD, PhD, a researcher and rheumatologist in the Department of Medicine, University of California, San Diego, addressed findings related to RA and diet. She also shared her own research in the area of nutrition and diet, including work on the anti-inflammatory diet (ITIS).¹

Dr. Guma discussed her findings with Dr. Hausmann, podcast host and a pediatric and adult rheumatologist in Boston. She pointed out that diet changes for those with RA are complementary to traditional treatments and do not involve changes to standard of care.

Patient Questions

Often, patients ask questions about diet after their initial diagnosis, when they are still coming to terms with having RA. “They always ask about something they can control. If you change your diet, that’s something you can control,” Dr. Guma says.

The challenge: Physicians—traditionally—have not had much training in nutrition, which can make it hard to answer diet-related questions.

An interest in diet and joint inflammation, as well as synovial tissue, has helped spur much of Dr. Guma’s research. She says research finds circulating mediators in the blood, such as cytokines and lipid mediators, increase or decrease inflammation and many are secondary to a patient’s diet.

“It made a lot of sense to try to see if by modifying the diet, you are also modifying these circulating inflammatory mediators,” she says.

In the course of her research, Dr. Guma and fellow investigators asked patients what they were eating. They found many are well educated, having already done some research about diet because it might help their RA. Many of these same people were rarely eating meat or gluten if those foods led them to experience more inflammation.

Nutrition research within RA has not always had a strict study design, making it harder to interpret the results, Dr. Guma says. Some trials focus on supplements, such as curcumin and omega 3 as anti-inflammatory. Some of these studies have good results, but the number of studies available to analyze is small, she says.

Another problem with the research is that it can be hard to change what people eat because it involves changing habits, Dr. Guma says. This difficulty in changing habits may be why literature results are sometimes contradictory.

The Microbiome

A major focus in diet and RA, as well as health in general, is examining the role of the microbiome. This area is ripe for research and exploration for people with RA.

Although some general perceptions of foods as good or bad for the gut exist, Dr. Guma explains to patients that each individual may react differently to a food because of the way each person metabolizes that food. “You are giving the same ingredient to different people, and they’re going to respond differently,” she says.

In some patients, it’s easy to modify the microbiome and make changes within a month or so. In others, the microbiome seems to be very fixed, Dr. Guma says.

These types of results indicate the potential need for a personalized medicine approach to changing diet, Dr. Hausmann says.

The ITIS Diet

During the podcast episode, Dr. Guma addressed the ITIS diet she helped design.¹ The information for the ITIS diet came from patient feedback, a dietitian on their study team and research findings. The goal was to build a diet that removed pro-inflammatory ingredients, such as meat and sugar, and added as many anti-inflammatory ingredients as possible in a way that was easy for patients.

The ITIS diet is similar to the Mediterranean diet, with some modifications. It focuses on not eating meat, but does not tell patients they have to completely avoid it. “[Patients] have some flexibility. Otherwise, it’s difficult for somebody to follow the diet,” Dr. Guma says. Instead of red meat, the diet encourages eating fatty fish, chicken and turkey.

Patients following the ITIS diet are encouraged to avoid gluten and dairy, but can have fermented dairy products, such as yogurt.

Although vegetables are considered healthy, potatoes and tomatoes are pro-inflammatory for some patients with arthritis and not encouraged on the diet.

Spices, such as turmeric, and anti-inflammatory oils, such as olive oil, are encouraged in the diet, as well as seeds and nuts. The ITIS diet discourages patients from eating fried foods. If a patient is going to fry their food, they should do it for a shorter amount of time and use olive oil.

Another goal of the diet is to encourage the consumption of more omega 3 fatty acids and less omega 6 fatty acids.

In a pilot study published by Dr. Guma and co-authors, 22 patients with RA followed the ITIS diet for two weeks while also using their prescribed medications.² Fifty percent of the patients cut their pain and swelling in half. They also improved their fatigue. The remaining patients felt better but did not have a measurable difference in their pain and swelling. This finding may be due to changes in the way people respond to the diet, or these patients may have needed more time to respond to it, she says.

At the time of the podcast, a trial was underway to track results over three months.

During the pilot trial with this diet, researchers provided many of the necessary ingredients. In the longer-term trial, the dietitian is meeting with study participants to help them find healthy options at their economical level.

Dr. Guma acknowledged that some of the healthy choices can get more expensive than normal diets.

Practical Implications

Dr. Hausmann asked for nutritional guidance rheumatologists can share with patients with RA.

The Arthritis Foundation has reliable information on food and nutrition, including background on ITIS, Dr. Guma says.³

“If a patient tries a diet like this and physically notices a difference, whether it’s less stiffness, pain or swelling, it’s going to be a huge motivator to keep going,” she says.

Dr. Hausmann emphasized that the diet changes some people may want to try should be done in conjunction with medications and traditional treatments for rheumatic disease.

“We are not telling people to replace their TNF inhibitors with a better diet,” he says.

References

1. Bustamante MF, Agustin-Perez M, Cedola F, et al. Design of an anti-inflammatory diet (ITIS diet) for patients with rheumatoid arthritis. Contemp Clin Trials Commun. 2020 Mar; 17:100524.
2. Coras R, Martino C, Gauglitz JM, et al. Baseline microbiome and metabolome are associated with response to ITIS diet in an exploratory trial in patients with rheumatoid arthritis. Clin Transl Med. 2022 Jul; 12(7):e959.
3. Rath L. ITIS: A supercharged Mediterranean diet for RA. Arthritis Foundation. 2022