What causes muscle pain similar to fibromyalgia in Covid?

And what causes pain in fibromyalgia in the first place?

Dr. Ayşegül Çoruhlu · July 20, 2022 · Back to the Blog & Research

Widespread pain in the muscles is today's common disease. Although a long way to go in treatment, there is no complete solution yet. The subject of this article is to examine the biochemical mechanism of fibromyalgia and to explain its similarity with common muscle pain in covid. Once I understand the mechanism, I will explain what we can do to stop these pains with a long list.

Fibromyalgia occurs with complaints of widespread muscle pain, decrease in the pain threshold in the muscles, tension in the muscles, stiffness in the muscles. There may be accompanying complaints; such as fatigue, weakness, depression, sleep and intestinal problems. In order to explain the cause of fibromyalgic pain, I will describe a few mechanisms.

The first mechanism I will address is the serotonin deficiency mechanism. Let's examine the effect of decreasing serotonin, which has a place in the treatment in reducing the symptoms of fibromyalgia, on pain.

Serotonin and tryptophan

It is generally defined as the happiness hormone. Mood balance is necessary for sleep and bowel movements to be smooth. The first thing we need to know; We need an amino acid called tryptophan for the production of serotonin. We get tryptophan with food. The fate of tryptophan that comes with food is to increase serotonin in the body. Increased serotonin will work as relaxed muscles, good sleep, working gut. However, in order to get tryptophan from food, it must be absorbed from the gut. Here there is a competitor to it, which blocks the absorption of tryptophan; fructose. As fructose in the intestine increases, tryptophan absorption and therefore the amount of serotonin decreases.

In today's diet, high fructose corn syrup, HFCS, is used abundantly in processed foods. The amount of fructose in the intestine increases, especially with the consumption of floury and sugary ready-made foods. Biochemically, this fructose interacts negatively with tryptophan, the precursor of serotonin. Especially if there is a lack of good bacteria in the gut, this interaction increases, as a result, the amount of tryptophan that passes into the blood decreases. So as we eat sweet-bread to feel good, we feel worse because of the loss of tryptophan and decreased serotonin.

Let's assume tryptophan doesn't compete with fructose and say we don't eat processed foods. This time we have to look at the fate of tryptophan in the liver.

Before tryptophan becomes serotonin, it has to convert to an intermediate called 5HTP. Tryptophan can only pass to the brain in this form to become Serotonin. 5HTP becomes serotonin first and we feel relaxed and good. Since melatonin is also made from serotonin, we can provide a good sleep. However, this is the ideal scenario. Another scenario comes into play in fibromyalgia: Serotonin steal syndrome; the serotonin stealing syndrome.

The other route that tryptophan will take outside of the serotonin pathway is an undesirable route, but some situations put serotonin on that path, so we call it the serotonin stealing route; its medical name is kynurenine pathway.

If tryptophan deviates from the serotonin pathway, the serotonin and its associated melatonin decrease. This unwanted pathway is provided by two enzymes in the liver. These two enzymes, which in a way degrade tryptophan, are activated if there is stress. High cortisol decreases tryptophan and thus serotonin. One of the explanations for being in a low mood when we are stressed is that this pathway is activated. Inflammatory cytokines other than cortisol activate this pathway. (These cytokines are the cause of the muscle pain in covid, which I will explain below.) If there is an inflammation in the body, such as inflammatory diseases in the intestine, increased cytokines activate this enzyme in the liver. As a result, the production of serotonin decreases. Another point is that the activity of these enzymes, which direct tryptophan to the bad pathway (the kynurenine pathway), increases with estrogen.

So far we have learned:

  1. There may be low serotonin in fibromyalgia;
  2. Serotonin is tryptophan and is taken with food;
  3. Intestinal fructose, especially fructose in processed flour-sugar foods in the form of HFCS, reduces the absorption of tryptophan and competes with it;
  4. Tryptophan normally becomes 5HTP and then serotonin. Serotonin is also converted to melatonin. This is the way we want;
  5. Serotonin stealing syndrome: serotonin is stolen like this; Tryptophan goes the way of kynurenine instead of serotonin. Serotonin in the body decreases;
  6. This pathway increases stress (cortisol), inflammation (cytokines) and estrogen.

Lactic acid

Now we must examine the lack of oxygen as another cause of fibromyalgia.

The explanation is as follows: The lack of oxygen in the muscles is very important because the pain in fibromyalgia is also related to the inability to produce enough energy in the muscles. The lack of oxygen in the body turns the production of oxygenated energy for energy in the muscles to the anaerobic pathway. The residue of the anaerobic pathway is lactic acid. In fibromyalgia, lactic acid accumulates in the muscles. Fatigue, weakness and pain due to lactic acid, which we call meat cut, occurs. We cannot be content with just associating oxygen with breathing. Oxygen is also decreased in anemia. The prevalence of anemia in women increases these complaints as the blood carries less oxygen due to anemia. Since this paragraph tells us the importance of transporting oxygen to the tissues with fibromyalgia, we explain that exercise is good for fibromyalgic pain; exercise increases tissue perfusion.

Let's move on to what can be done for the treatment of fibromyalgia:

  • Avoid ready-made fructose-containing foods;
  • Increasing foods containing tryptophan;
  • Having enough stomach acid to digest the proteins, which are the source of tryptophan, well in the stomach;
  • Reducing the amount of stress so that tryptophan is not stolen;
  • Reducing inflammation so that tryptophan is not stolen: The first thing to do is to support gut health. (gluten-free foods, probiotics, colostrum, digestive enzymes, stomach acid supplements, zinc);
  • To ensure adequate oxygen supply to the muscles: exercise, massage, yoga, breathing exercises, correction of anemia;
  • Receiving magnesium support. Magnesium helps both muscle relaxation and energy generation in the muscle;
  • Going out in the sun: The infrared wavelength in the sun's rays helps muscle relaxation. In addition, sunbathing increases the nitric oxide in the veins and relaxes the veins, so that more oxygen can circulate in the body;
  • Switch to a diet that reduces carbohydrates but increases fat and vegetables;
  • To support fat burning in order to reduce the lactic acid formed as a result of oxygen-free glucose burning in the muscles with l-carnitine supplement;
  • Getting 5HTP support.

Covid and muscle pains

If we come to the subject of muscle pain in Covid, a situation similar to the serotonin stealing syndrome I described above occurs. According to the results of the study, the pathway of kynurenine increases in covid positive patients. In other words, this pathway is activated instead of serotonin. I wrote that two enzymes in the liver that provide this pathway are activated by cytokines. Increased Interleukins (especially IL6) and interferon in Covid stimulate these enzymes. Tryptophan goes this way, not the serotonin pathway. Serotonin deficiency manifests itself as muscle fatigue, pain and depressive mood.

In this article, although I wrote the subject under the title of fibromyalgia, the same content would have been present even if the title was depression. Therefore, those who feel depressed, chronic fatigue, weakness, malaise, sleep problems can read this article as well as those who feel muscle pain. The solutions are also similar.

Let's finish our article with a list of foods containing tryptophan:

  • Meat: liver, turkey breast, chicken breast;
  • Eggs;
  • Fish: sardines, mackerel, salmon;
  • Fruits: banana, pineapple, avocado;
  • Nuts: peanuts, cashews, almonds, walnuts;
  • Goat-sheep milk, soybean;
  • Vegetable: beans, chickpeas, brown rice, spinach, peas;
  • Seed: pumpkin seeds, sesame, fenugreek, flaxseed, sunflower;
  • Chocolate, cocoa.

I wish you a year full of youth.


Dr. Ayşegül Çoruhlu

Dr. Ayşegül Çoruhlu

Dr. Ayşegül Çoruhlu is a licensed Turkish physician and specialist in Anti-Ageing, Biochemestry, and Biomedical Engineering.

View her biography

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