ITIS: A Supercharged Mediterranean Diet for RA
A new approach to a popular diet shows a positive effect on the microbiome, a key player in inflammatory arthritis severity and outcomes.
By Linda Rath
Diets fall in and out of favor, but the Mediterranean diet has stood the test of time. Decades of research have shown that a plant-based mix, including vegetables, fruit, legumes, olive oil, fish and whole grains, can improve or prevent many chronic diseases, including heart disease, type 2 diabetes and arthritis.
Scientists trace the diet’s benefits in part to its positive effect on the microbiome — the rich ecosystem of microbes, or microorganisms, that inhabit our bodies, especially the gut.
What you eat can encourage or inhibit the growth of certain types of gut bacteria, increase or decrease overall diversity and influence metabolites the microbes produce, which are key players in activating inflammation. An unhealthy microbiome — one that’s less diverse and unbalanced — is associated with autoimmune diseases like rheumatoid arthritis (RA) in susceptible people.
Mediterranean Diet 2.0
“We know the Mediterranean diet is good for patients with rheumatoid arthritis,” says Monica Guma, MD, a rheumatologist and researcher at the University of California, San Diego. “But there also might be something better.” That something is what she calls the ITIS diet. It’s the Mediterranean diet supercharged with anti-inflammatory foods and herbs that may improve gut health and arthritis symptoms.
She and her colleagues spent a year designing the diet. At four different stages, they consulted patients to make sure the diet was affordable and was one they could stick with for the two-week study period. They made a few changes as needed.
The diet includes a lot of things the standard Mediterranean doesn’t, including:
- A home-made green drink (green vegetables and fruit) every morning
- Oily fish such as sardines, salmon or tuna at least twice a week
- A high daily intake of monounsaturated fatty acids (MUFA) from avocado, nuts, sesame seeds or sesame butter (tahini)
- Daily chia seeds and flaxseed oil
- Unsweetened yogurt and miso, a fermented soybean paste
- Fruits high in enzymes, such as pineapple and papaya
- Daily green tea
- Turmeric (used with black pepper for better absorption) and ginger
It also excludes some things the Mediterranean diet allows:
- Wheat flour and gluten
- Tomatoes, potatoes and eggplant, which may worsen arthritis symptoms in some people
- Combining protein with grains (spaghetti and meatballs, for example)
Red meat, sugar, soda and processed or fast foods are out of bounds in both the Mediterranean and ITIS diets.
ITIS Diet Study Results
Twenty-two highly motivated patients with doctor-diagnosed RA followed the ITIS diet for two weeks. They continued taking prescribed medications during the study. Half experienced a 50% improvement in pain and swelling as well as in subjective measures such as fatigue, often in three or four days. A few patients went into complete remission.
“They got better really quickly,” Dr. Guma says.
What about the 50% of patients who didn’t respond? Dr. Guma says everyone felt better, had more energy and less fatigue. But it’s not clear why some didn’t have less pain and swelling, too.
Dr. Guma says the patients who saw the most improvement had better diets and microbial diversity to begin with. It’s possible the others may have needed more time. It’s also possible a subset of people may never respond due to certain conditions that inhibit the microbiome from changing as quickly or as much. This is especially true if the microbiome gets off track early in life. Caesarean birth, for example, prevents infants from picking up healthy microorganisms in the birth canal. Antibiotics in infants and kids can wipe out most gut bacteria, which may never completely repopulate in a healthy way. Many other factors influence gut health, too, including childhood stress, trauma or poor diet.
Despite the remarkable success of the diet for some people, Dr. Guma emphasizes she’s not suggesting it can replace arthritis drugs.
“Many patients need meds to slow out-of-control disease. But diet can complement regular medical care; it can decrease the need for nonsteroidal anti-inflammatories and other drugs and may make it possible to taper off them at some point.”
The study has several important limitations: There was no control group for comparison. It’s also impossible to know if ITIS has long-term benefits. In studies of the Mediterranean diet, the benefits disappeared when people stopped following it.
Dr. Guma plans to conduct longer trials with more participants who will work closely with dietitians.
“People often want to change their habits, but it’s difficult to change them all at the same time,” she says. “This was a short trial just to see if people could follow the diet. About 80% of the participants said it was easy to make these dietary changes. Some are continuing to follow the diet on their own, but there will be times when they don’t. We just tell them to do the best they can.”