Histidine is a semiessential amino acid, which means your body
normally makes as much as it needs. Like most other amino acids,
histidine is used to make proteins and enzymes. The body also
uses histidine to make histamine, the culprit behind the
swelling and itching you feel in an allergic reaction. It
appears that people with rheumatoid arthritis may have low
levels of histidine in their blood. This has led to some
speculation that histidine supplements might be a good treatment
for this kind of arthritis, but so far no studies have confirmed
this. Although histidine is not required in the diet, histidine
deficiencies can occur during periods of very rapid growth.
Dairy products, meat, poultry, fish, and other protein-rich
foods are good sources of histidine. A typical therapeutic
dosage of histidine is 4 to 5 g daily. Although individuals with
rheumatoid arthritis appear to have reduced levels of histidine
in the blood,1,2 this by itself doesn't prove that taking
histidine will help. One study designed to