Patients with rheumatoid arthritis are often eager to try dietary interventions in an effort to improve their symptoms. For guidance, they turn to their rheumatologists, who typically can offer little in terms of concrete evidence-based recommendations. That’s because their training didn’t emphasize the role of nutrients in rheumatic diseases, the scientific evidence has historically been sketchy, and the topic of diet and disease is rife with fad diets, inflated Internet claims, and hucksterism.
Bruce Jancin/MDedge News
Dr. Orrin M. Troum
But that’s changing. Indeed, recent annual meetings of the American College of Rheumatology have featured randomized, controlled trials that bring welcome rigor to the field and provide findings of practical interest to clinicians and their patients, Orrin M. Troum, MD, said at the 2021 Rheumatology Winter Clinical Symposium.
He highlighted some of this work, including positive randomized trials of the dietary supplements Biqi – a traditional Chinese herbal medicine – as well as turmeric, along with reported progress in efforts to design a palatable anti-inflammatory diet that favorably alters the gut microbiome and systemic metabolome while improving clinical outcomes in patients with RA.
Dr. Troum, a rheumatologist at the University of Southern California, Los Angeles, and in private practice in Santa Monica, described a typical patient encounter in his clinic that appeared to resonate with his audience from throughout the country: “You can tell people to take another medicine and they’ll start shaking their head no before you’re finished. But when you say there are natural supplements that can help you, they’re saying ‘Yes!’ ”
RA improvement on an ITIS diet
Many physicians recommend a Mediterranean-style diet, first popularized in the landmark Seven Countries Study launched by the late Dr. Ancel Keys. This familiar plant-based regimen emphasizes liberal consumption of extra-virgin olive oil, legumes, fruits and vegetables, whole grains, fish, nuts, and moderate alcohol intake, with very limited intake of red and processed meats, refined grains, and sugar. There is strong evidence that the Mediterranean diet is cardioprotective, which is relevant to patients with RA since they are known to be at elevated cardiovascular risk.
However, investigators at the University of California, San Diego, became convinced that the Mediterranean diet is lacking in key anti-inflammatory ingredients from other parts of the world. These include ginger, green tea, black pepper, turmeric, miso, flax seeds, and tahini, all of which are backed by evidence – from animal models and/or interventional diet studies in patients – that suggests beneficial effects in pain and joint swelling in RA. The researchers also suspected that certain vegetables embraced in the Mediterranean diet – notably eggplant, tomatoes, and potatoes – might be problematic for RA patients because they contain solanine, thought to increase intestinal permeability, which might have arthritogenic effects on the gut microbiome.
The investigators set out to develop an anti-inflammatory diet they call the ITIS diet, essentially tweaking the Mediterranean-style diet by incorporating these additions and subtractions. Importantly, they designed the ITIS diet in conjunction with a multiracial local group of RA patients strongly enthusiastic about the potential for dietary interventions aimed at improving their symptoms. The patients provided feedback that enabled the investigators to fine-tune the anti-inflammatory diet so as to boost palatability and acceptance.
As an illustrative example of the ITIS diet, a typical day might start off with a homemade smoothie of parsley, pineapple, strawberries, and water, followed by a breakfast consisting of one or two corn tortillas spread with avocado, linseed oil, and sesame seeds, accompanied by green tea. Following a mid-morning snack of plain Greek-style yogurt, lunch might be a choice of a large salad, legumes with vegetables, or whole grains with vegetables. For the afternoon snack: four walnuts plus mango, banana, pear, papaya, apple, or pineapple. And for dinner, the options are vegetable soup and a protein; salad plus a protein; or miso soup, cooked vegetables, and a protein.
At the 2020 ACR annual meeting, Roxana Coras, MD, presented the positive findings of an open-label, pilot study of the ITIS diet in which 17 patients with active RA involving at least three tender and three swollen joints adopted the diet for 2 weeks . The ITIS diet turned out to be not too much of a stretch for Southern California RA patients interested in dietary complementary and alternative medicine. Many had already adopted some elements of the anti-inflammatory diet. Dietary adherence in the study was good, as monitored in food logs and by mass spectrometry metabolic profiling of fecal and plasma samples.
Eleven patients were categorized as responders to the anti-inflammatory diet as defined by at least a 50% improvement in pain scores from baseline to 2 weeks; six patients were nonresponders. In the overall study population, mean pain scores on a 0-10 visual analog scale improved from 3.9 to 2.45. Scores on the Clinical Disease Activity Index (CDAI) also improved significantly on the ITIS diet, from 29 to 12.7, reported Dr. Coras, a rheumatologist at the University of California, San Diego.
The mechanisms for the clinical improvement on the diet are under study. Significant differences in the gut microbiome and metabolome were seen between the responders and nonresponders. For example, Mollicutes were increased and Coriobacteriales decreased in clinical responders versus nonresponders. A significant increase in circulating levels of anti-inflammatory oxylipins was also seen in responders. Longer-term controlled studies of the ITIS diet are planned.