Against joint pain, should we go “gluten-free”? Or rather avoid cow’s milk? Fasting? Unless the relief comes from Dr. Seignalet’s diet? Ketogenic diet? Perhaps we should otherwise eat like hunter-gatherers? And why not take turmeric capsules? Garlic extract? Probiotics? In pathologies such as osteoarthritis or arthritis, very common diseases, medical advances in recent years have brought significant progress, but without however succeeding in providing complete relief to patients. As is often the case when medicine does not have the answer to everything, pseudo-therapeutic proposals flourish on social networks and on the Internet, and patients may be tempted to try one or other of these so-called solutions. “miracle”, without necessarily talking to their doctor.
To answer patients’ questions, but also to alert them to the dangers of these often eccentric recommendations, two professors of medicine, the rheumatologist Jérémie Sellam and the nutritionist Sébastien Czernichow are publishing these days a book that is both fascinating and educational: Osteoarthritis, arthritis, I treat myself by eating (Solar). Because yes, if it does not do everything, and cannot replace medications, diet plays an important role in joint pain. A priori counterintuitive, the links between nutrition and joints are nevertheless easily explained. “Inside the joints, the synovial membrane is very vascularized and provides the necessary nutrients to the cartilage,” explains Professor Czernichow. “It is therefore not isolated from the rest of the body, quite the contrary: it is exposed to everything that circulates in the blood. And in particular to inflammatory molecules, which are particularly harmful.
Inflammation is indeed the main cause of joint diseases. Either it causes them directly, as in arthritis. Either it is the consequence of a “mechanical” problem (overweight, obesity, injuries, etc.) as in osteoarthritis, which it will then contribute to aggravate. In both cases, the result is the same: the molecules of inflammation will attack the tissues of the joint. “We distinguish the two phenomena for a good understanding of the pathologies, but in reality, everything is very intricate. How else can we explain osteoarthritis of the hands, which cannot be linked to weight unlike osteoarthritis of the knee or hips?” , underlines Professor Czernichow. And this is where we come back with food, because it has been widely demonstrated that it is possible to influence your level of inflammation through diet.
Patients know this well. In a study led by Professor Sellam with 392 participants (Rhumadiet study), it appeared that they noticed an improvement or deterioration in their symptoms depending on the foods consumed. With on one hand, for example, green vegetables or olive oil seen as beneficial, and on the other hand, alcohol or cheese seen as pejorative. “Beyond this feeling, which can be completely real on an individual basis, it is then up to scientists to carry out the necessary studies to distinguish a person’s impressions from generalizable measurements, which can be advised more widely to patients” , underlines Sébastien Czernichow.
The Mediterranean diet, the only one that has proven itself
This is the great merit of this work: giving the reader the keys to distinguishing science and belief, and making rational food choices. “To recommend a diet or dietary pattern to a patient suffering from rheumatism, a single study will not be enough, nor will experiments carried out only in the laboratory on cells in culture or on mice. Several studies will have to be concordant in order to confirm a recommendation nutritional”, write the two doctors. However, to date, only one “diet” ticks all these boxes: the Mediterranean diet.
Less sexy than the latest fashionable diet, and yet… Studies have clearly shown that the more patients adhere to this dietary model, the better their rheumatism is controlled, or the less it progresses. This observational work is useful but considered to have a low level of proof: a correlation does not necessarily imply a causal link. But these analyzes were supplemented by so-called “interventional” studies, which consist of comparing the evolution of patients randomly distributed between two groups, one following a Mediterranean diet, the other continuing their usual diet. A method similar to current clinical trials for evaluating drugs.
Detailed by the two specialists in their book, all the available data confirm the benefit of this diet for patients suffering from rheumatism. “It can therefore usefully complement drug treatments,” emphasizes Professor Jérémie Sellam. Mainly comprising whole grains, fruits and vegetables, olive oil, fish and dairy products, the Mediterranean diet is also low in fatty meats and fast sugars. Rich in fiber, it probably has an action on the intestinal microbiota (the billions of bacteria that make up our intestinal flora), itself very involved in the regulation of inflammatory mechanisms. Maintained over time, it allows weight loss, and contributes to an overall improvement in health, by reducing the risks of diabetes or cardiovascular diseases.
Difficult to do better. However, in the Rhumadiet survey conducted by the two researchers, only 5% of participants followed this diet. A figure undoubtedly a little underestimated in relation to the practices of the population, recognize the authors of the study, but to be compared with the dietary recommendations mainly adopted by the participants in this survey. Most resorted to gluten-free, lactose-free, vegetarian diets, when they were not fans of therapeutic fasting. So many diets based on food exclusions, particularly difficult to follow over time, which have not yet proven their usefulness, and which can even prove risky. “Patients carry out tests on themselves, they allow themselves to be seduced by these complicated exclusion regimes because this complexity often seems to them to be a guarantee of effectiveness, a bit like when we say ‘you have to suffer to be beautiful’ “, testifies Professor Sellam.
Current studies
For each of these so-called exclusion diets (gluten-free, lactose-free, etc.), the two doctors go back to the sources of belief, and review the available scientific literature – generally very limited and, for the few existing works, with negative results, or insufficient to draw reliable conclusions. Example with the gluten-free diet, probably the most followed. “Gluten is seen as harmful, because it can attack the wall of the intestine and cause inflammation, explain the two authors. This is true, but only in the context of a very specific disease, the disease celiac”. It is impossible to extrapolate this observation to joint diseases. Especially since to date, no study has correctly evaluated “gluten-free” in patients suffering from rheumatism. No dogmatism here, however: “A study is underway in spondyloarthritis, carried out by a French team based in Clermont-Ferrand, we will see what the results are. This work is important to provide reliable answers to patients”, continues Professor Sellam.
Waiting ? If a patient has already started, and finds the best, why not but be careful of the deleterious effects. Otherwise, it is better to abstain, according to the two authors. Because not only are “gluten-free” products expensive, but they can also… harm your health, by causing vitamin and mineral deficiencies, and by increasing the consumption of salt, sugars and bad fats. Other diets are suitable, as are food supplements, none of which have proven their effectiveness. No more than probiotics, although they are supposed to act on the intestinal flora. “The probiotics available today are the easiest to produce, but not necessarily the most effective […] and a probiotic will not in any case act in the same way depending on the state of the microbiota of the person consuming them”, note the two doctors. Clearly, if they are promising, the science is still not clear today not sufficiently advanced to allow us to advise them.
“Unfortunately, some do not hesitate to play on the distress of patients,” regrets Sébastien Czernichow. His advice to sellers of “miracles”: “Ask for proof of the claimed effectiveness,” he summarizes. In nutrition as in many other areas, the scientific method remains the best defense against false beliefs. And the only possible path to truly informed choices.
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