While reviewing some research articles to be used as references in a book, I came across one today that is almost 30 years old, but it explains why so many of us have histamine problems associated with MC. In this study, rats fed a magnesium-deficient diet for 8 days showed significantly increased histamine levels in their urine after 4 days, and the histamine reached a maximum level on day 8. Increased histamine levels could be found in tissues also, by day 8. When the magnesium deficient group was fed a higher magnesium diet for 2 days, their histamine (and serum magnesium) levels returned to the same levels as the controls. The body makes histamine from histadine. Histidine decarboxylase (HDC) is the enzyme that catalyzes the reaction that produces histamine from histidine (with the help of vitamin B-6). Note the significance of this quote from the abstract of the article at the link below.
And in addition, by day 8 on a low magnesium diet the diamine oxidase (DAO) level of the rats was approximately half the level of the controls. As most of us are aware from past discussions here, DAO is the enzyme used by the body to purge left-over (unused) histamine from the system. Without adequate DAO, histamine can build up in the body, eventually causing symptoms.Histidine decarboxylase (HDC) activity in some tissues of Mg-deficient rats increased markedly. The increased HDC activity dropped nearly to control levels after feeding them a 0.21% Mg diet for 2 days.
This is almost surely the reason why so many of us have histamine issues associated with our MC — obviously many of us are magnesium deficient.
Specific change of histamine metabolism in acute magnesium-deficient young rats.
The research data indicate that recovery should be relatively prompt (within a couple of days) after adjusting the diet to provide 3 times the normal magnesium requirement. But most of us don't see such a prompt response. For one thing, most of us don't take that much magnesium — that would require approximately 1,200 mg per day, which might cause problems for someone who has MC. In addition I have a hunch that this may be influenced by the fact that the rats in this study were not magnesium deficient at the start of the 8-day study, whereas most of us are initially magnesium deficient.
If we have a long-term magnesium deficiency then some of the dietary magnesium will surely go to tissue reserve replenishment. We know this happens because increased magnesium intake promptly resolves muscle cramps. And most of us have a malabsorption problem, so our absorption of magnesium is not likely to proceed at a normal rate. So with a lower supplementation rate, a reduced absorption rate, and much of the magnesium going to resupply depleted muscle reserves, it's not surprising that it takes us much longer to resolve a magnesium deficiency compared with the rats in this study.
So there you have it — my take on why so many of us have histamine issues associated with our MC. There's a reason for everything — we just have to find it.
Tex