Fasting with Rheumatoid Arthritis: What Studies Show About Inflammation, Joint Pain and Gut Flora

Just after six. Maybe you know this moment.

If you recognize yourself in this scene, you are not alone. Many people with rheumatic disease ask about diet and fasting. A single account is not proof. But it is a good reason to ask an honest question.

When I talk about rheumatic disease here, I mainly mean rheumatoid arthritis, RA for short. It is the condition with the most fasting studies. I am writing as a physician who values fasting and respects rheumatological therapy. Three questions interest me: What do the studies show in the short term? Why do the symptoms return so often? And how are the gut, the immune system and the joints connected?

Can fasting lower inflammation and joint pain in rheumatoid arthritis?

In short: In several small studies of rheumatoid arthritis, pain, stiffness and inflammatory markers fell during a fasting phase of seven to ten days. In a randomized trial from Oslo, the improvements lasted for a year when fasting was followed by a vegetarian diet. The studies are small, and some are old. Promising, but not conclusively proven.

Maybe you are feeling two things at once right now. Hope, because there is something you can do yourself. And skepticism, because you have already tried so much. Both are allowed to be there.

The idea is old. As early as 1979, a team led by Sköldstam described what a fasting week can change in rheumatoid arthritis. The results were encouraging and sobering at the same time.

Twelve years later, a team at the University of Oslo asked exactly this question about the time afterward. The researchers themselves write that most people with RA relapse once they start eating again. That is why they combined fasting with a long change in diet.

The guideline on fasting therapy, written by an expert panel in fasting medicine, also assigns rheumatic diseases the highest level of evidence among the indications for fasting. That sounds impressive. Compared with drug trials, however, the numbers of participants are small, and most of the studies are decades old.

What does this mean for you? If the topic appeals to you, bring it up at your next rheumatology check-up. Don't just ask: Am I allowed to fast? Also ask: How do I eat afterward, and how will we recognize together whether it is doing me good?

And now you know why your acquaintance's account can be true and still be only the beginning of the story.

Why do symptoms often come back after fasting?

In short: A systematic review of 70 human studies describes the improvements from fasting in rheumatoid arthritis as clear, but temporary. In older studies, they were often lost once people returned to their usual diet. After Ramadan, the values slowly rose again over a good three months. Effects lasted longer mainly when fasting was followed by a change in diet.

Imagine your fasting week went well. Your fingers were more flexible, your mornings easier. Three weeks later, the stiffness is back. That feels like a setback, maybe even like a personal failure.

It is not a failure. It is a pattern that research has been describing for decades.

Ramadan provides a more recent example. A team from Tunis followed people with rheumatoid arthritis beyond the month of fasting.

This comparison summarizes the studies in this article. Not every study measured every point.

Why is that? Nobody knows for sure. One plausible explanation: for a while, fasting takes away stimuli from food and the gut that reach the immune system. When the old diet returns, these stimuli probably return too. That is a hypothesis that fits the data, not proof.

The Oslo group checked what happened after the study year. Afterward, participants were free to choose their diet and medication.

Plan the time afterward before you begin. Together with your doctor, think about which diet you can realistically keep up after fasting. You can read about how the transition from fasting back to eating can go well in the article Breaking your fast the right way.

And now you know why a relapse after fasting is not a coincidence, but a clue.

What happens to your immune cells when you fast?

In short: In rheumatoid arthritis, immune cells in the blood released fewer inflammatory substances during a fasting week. In one study, their ability to kill bacteria even increased. In healthy people, the number of monocytes in the blood fell after 19 hours of fasting. So fasting does not seem to switch the immune system off, but rather to throttle its constant operation.

Maybe you are worried that fasting weakens your immune system. Especially if you already take medication that dampens the immune system. That concern is legitimate and deserves an honest answer.

Imagine your immune system in rheumatoid arthritis as a fire department that never goes off duty. Even without a fire, trucks keep heading out. Neutrophil granulocytes are the fast first responders. Monocytes are the reinforcements that stream from the bone marrow into the tissue and mature there into scavenger cells. In the inflamed joint lining, it is mainly monocytes and the scavenger cells derived from them that shape the picture.

A Berlin study, which you will read more about in the next section, saw a similar picture in people with RA. Its most striking finding was an increased turnover of monocytes, which improved within a few days after bowel cleansing and fasting. At the same time, the inflammatory messenger IL-6 fell.

What does this mean for you? If you take medication that dampens the immune system, fasting belongs under medical supervision. With a fever or an acute infection, I would not start a fast, but would first have a doctor clarify what is going on.

And now you know why fasting might calm your immune system rather than weaken it, and why supervision still matters.

Gut, immune system, joint: What does the gut flora have to do with rheumatoid arthritis?

In short: In people with rheumatoid arthritis, the gut flora is more often altered. In an animal model, stool from people with early RA was able to promote arthritis. In a Berlin study, disease activity improved in 19 of 20 people with RA after bowel cleansing and seven days of fasting, and IL-6 and the barrier marker zonulin fell. Whether the gut is a cause or a contributing player in humans is still an open question.

What does your belly have to do with your fingers? The question sounds strange at first. But maybe you have already noticed that bad days in your gut and bad days in your joints sometimes coincide.

Your gut is the largest contact surface between your body and the outside world. Imagine it as a border with many gates. The gut lining is the fence, the gut bacteria are the neighbors on the other side. A large share of your immune cells is stationed at this border and learns there what is harmless and what is not.

And what happens when people with RA fast? That is exactly what a team at Charité Berlin investigated.

DAS28 is a score for disease activity. It is made up of 28 examined joints, an inflammatory marker and your own assessment.

Back in the 1990s, a team at the University of Turku analyzed the stool samples from the Oslo study. With the switch to a vegan diet, the gut flora changed markedly. The flora of people who responded strongly to the diet differed after one month and after 13 months from the flora of those who responded little.

It is not quite that simple, though. In 2005, a study from Essen that used classic stool cultures found no measurable change in gut bacteria after fasting or a Mediterranean diet. There, the improvement in symptoms was not linked to the gut flora. The authors called for the question to be clarified with newer molecular methods.

And one more thing is important: the gut flora does not respond only to diet. In a large metagenomic study from Beijing and Shenzhen, the altered gut and oral flora in people with RA partly receded after treatment. So your rheumatological therapy also talks to your gut.

If you want to dive deeper into the gut barrier, the article Leaky gut and zonulin puts it into context. You can read what a break from eating does to the microbiome in Fasting and gut health. A simple first step: for a while, write down your digestion and your joints side by side. Patterns often only become visible on paper.

And now you know why your belly might have more of a say in your joints than it first seems.

Fasting week, intermittent fasting, Ramadan: What do newer studies show?

In short: In the Berlin NutriFast study, disease activity improved about as much after seven days of fasting followed by a plant-based diet as it did with a standard anti-inflammatory diet. The fasting group improved faster and lost more weight. For intermittent fasting, there is one small randomized trial showing better disease activity, but no change in CRP and IL-6. Ramadan studies are observations that cannot reliably establish a cause.

Maybe you are wondering: Does it have to be a whole week right away? Is there a gentler way? And do I have to give up everything I like to eat forever afterward?

This overview summarizes the studies in this section. It is not a recommendation for any particular form.

A German-language review from Charité puts it this way: for intermittent fasting, effects on the heart and metabolism have been shown so far, but antirheumatic effects have not. For longer, medically supervised therapeutic fasting in RA, it describes several clinical studies with symptomatic benefit. When a vegan or vegetarian diet follows, effects of up to one year have been documented.

And Ramadan? In Tunis, DAS28 fell from 4.3 to 3.5 in 36 people with RA who fasted. Taking their long-term medication remained largely unaffected. A study from Lahore in Pakistan with 240 people with RA, however, calls for caution. There, disease activity also improved over the same period in those who did not fast, on average even slightly more. However, those who did not fast started out with higher values. If you fast during Ramadan, you will find further guidance in the article Fasting during Ramadan.

The 2009 Cochrane review remains cautious. It found 15 studies with 837 participants and considered the effects of dietary changes in RA uncertain because the studies were small. In the diet groups, ten percentage points more people dropped out of the study, and they lost on average 3.2 kilograms more weight. The authors warn not to overlook possible side effects. You can read why preserving muscle matters during fasting in the article Fasting and muscle preservation.

Choose the form that suits your situation, not the strictest one. For some people, medically supervised therapeutic fasting is the right framework, as described in the article on Buchinger therapeutic fasting. For others, a gentle eating window is more realistic, more on this in Intermittent fasting 16:8. What matters is what ends up on your plate afterward.

And now you know why it is not the form of fasting alone that counts, but what comes afterward.

Fasting and rheumatoid arthritis medication: What you should not decide on your own

In short: In the modern fasting studies on rheumatoid arthritis, disease-modifying therapy continued unchanged. Don't pause methotrexate, biologics or other disease-modifying drugs on your own for a period of fasting. Never stop cortisone suddenly. According to the fasting therapy guideline, NSAIDs and cortisone are among the medications that need to be adjusted during fasting, and that is a job for a physician.

Maybe you secretly hope that fasting could let you cut back on pills. That is an understandable wish. Many people with rheumatic disease carry their medication like a heavy backpack.

This is where an honest look at the studies is worthwhile. In the NutriFast study, all participants had to have been on stable therapy for at least eight weeks, and it was not substantially changed during the study. In the Berlin study with bowel cleansing, the immunosuppressive therapy also remained stable. So what was measured was the effect of fasting in addition to therapy, not instead of it.

The fact that your body produces a little more cortisol of its own during fasting does not change this. In the Berlin fasting study, the body's own cortisol did rise. According to the authors, however, the increase corresponded to at most about 2.5 milligrams of prednisolone a day, too little to explain the improvement. It is not a substitute for prescribed cortisone therapy.

And now you know why your pills do not belong in a drawer during a fasting week, but in the conversation.

Rheumatoid arthritis through the KPNI lens: four systems in conversation

Back to your hands in the morning. Why are they so stiff at exactly that time? They were fine in the evening. This question leads right into Clinical Psychoneuroimmunology, KPNI for short.

KPNI does not look at the nervous system, immune system, metabolism and hormonal system separately, but as one conversation. In rheumatoid arthritis, this conversation is easy to observe.

I see a fifth level as well: your inner stance. For Nonviolent Communication, Marshall Rosenberg coined a principle that fits here: observing is something different from evaluating. “My fingers need half an hour today before they move freely” is an observation. “I failed at fasting” is an evaluation. When you separate the two, frustration turns into information that you and your doctor can work with.

And now you know why your stiff hands in the morning are a conversation between four systems and not just a problem of the joints.

Three levers if you are considering fasting with rheumatoid arthritis

You do not have to fast. If you are considering it, these three directions can give you orientation. They are not a treatment plan.

If you would rather not assess your situation on your own: below this article, you will find the option to book an appointment.

And now you know why the most important step is not the first day of fasting, but the conversation before it.

Frequently asked questions about fasting with rheumatoid arthritis

Where this topic touches other areas

Fasting with rheumatoid arthritis touches on autoimmunity, the gut barrier, inflammatory markers and diet. If you want to go deeper, these related topics are worth a look.