Fibromyalgia is a poorly understood and somewhat controversial diagnosis. Often referred to colloquially as chronic pain syndrome, the diagnostic criteria for the condition have been evolving.
The first set of general criteria were introduced in 1990 with updated versions floated in 2010 and 2011, but some clinicians have remained skeptical, as there has been a widespread belief that the condition had a strong psychosomatic component. Other, hard to categorize conditions have seen the number of diagnoses explode and then recede, such as chemical sensitivity disorders. Would fibromyalgia prove to be another similar diagnostic flavor of the month?
Another set of criteria developed by researchers was introduced in a 2019 paper that advocates a three-step approach to the diagnosis of the condition. This includes measuring the patient’s general pain response, verifying that the pain sensations are symmetrical on both sides of the body and using a standard assessment tool to rule out a pathological state of psychological stress.
The present review of the effects of supplementation was published in the journal Nutrients. The authors were associated with two universities in Florence, Italy.
The authors noted that while the diagnosis remains controversial, the syndrome appears to affect about 2% to 8% of the population, and is a leading cause of referral to rheumatologists. The etiology of the syndrome is unknown, however, which the researchers said makes the pathophysiology of the disorder uncertain.
"Various evidence supports the hypothesis that FM is a ‘central pain disorder,’ with alterations in central nervous system function leading to increased nociceptive processing. Furthermore, recent evidence suggests that low-grade systemic inflammation, a preponderance of prooxidative status and an insufficient antioxidant capacity, could contribute to the development of the disease, reducing the pain threshold and inducing fatigue and mood disorders,” they wrote.
The researchers noted that dietary imbalances appear to be a common feature of fibromyalgia (FM). FM suffers frequently try to address their conditions with dietary interventions, either on their own or at the advice of a clinician. The authors noted that almost three quarters of FM sufferers were found to be using dietary supplements, with 61% of those having started using supplements after having developed their conditions.
Strongest evidence for vitamin D, magnesium
Vitamin D was one of the most important nutrients in this regard, as the researchers noted that 40% of FM sufferers have been reported to be vitamin D deficient. A placebo-controlled study with 90 subjects using a high dose of vitamin D found significant reduction in FM symptoms in the treatment group, the authors wrote.
Similarly, magnesium has shown promise, with a recent study showing low magnesium levels were associated with a lower threshold of pain response in FM subjects. But there are only two clinical trials to go on, the authors noted. Similarly, iron supplementation has shown some benefit, but in that case there is only one clinical trial to point to.
Less evidence supports vitamins C, E and probiotics
The fact that antioxidant levels in FM suffers tend to be low and oxidative stress seems generally to be high would argue in favor of supplementation with vitamins C and E. While the argument would appear persuasive, there are no consistent studies to support the notion, the researchers said.
Similarly, it has been shown that FM sufferers exhibit gut microbiome differences to the general population, so an intervention with probiotics would seem to offer the promise of some benefit. The researchers said only one small scale study has been done, and the results showed improvements on some measures of FM symptoms, but not on others.
As for dietary interventions, some approaches have shown moderate promise, such as adherence to a FODMAP eating plan, vegan diets, gluten-free diets, caloric restriction and others. But no one approach seemed to offer universal benefit, they noted, which could be partly attributed to the big overlap FM has with other conditions, such as IBS or gluten sensitivity.
“This review embraced the literature and showed that the role of dietary supplements on FM remains controversial, although clinical trials with vitamin D, magnesium, iron and probiotics’ supplementation show promising results. In terms of dietary interventions, the administration of olive oil, the replacement diet with ancient cereals, low-calorie diets, vegetarian diets, the low-FODMAPs diet, the gluten-free diet, the monosodium glutamate and aspartame-free diet and the Mediterranean diet all appear to be effective in reducing the symptoms of FM,” the authors wrote.
“Although dietary aspects appear to be a promising complementary approach to treat FM, further research is needed to improve the understanding of the disease and to provide the most effective strategies for managing FM syndrome,” they concluded.