London, April 23: A few cups of tea a day may keep illness away by boosting the body’s protective immune system, according to a study published yesterday.
Drinking certain types of tea containing high concentrations of an amino acid called L-theanine may help to fight off infection, a team at Brigham and Women’s Hospital in Boston reports. The findings are reported in the Proceedings of the National Academy of Sciences.
Earlier work revealed that tea contains flavonoids, potent antioxidants that can help protect the body from damaging chemical intermediates called free radicals.
“The health benefits of tea have been touted for centuries but no human research has demonstrated an association between tea drinking and immunology,” Dr Jack Bukowski, the lead author, says. “Now we have a new explanation for the medicinal effect of tea. Our data suggest that the amino acid L-theanine may specifically boost the capacity of gamma delta T cells, the body’s first line of defence against infection.”
It has also been shown that, once introduced to a natural form of L-theanine, commonly found in bacteria, vegetables, wine and tea, the disease-fighting capabilities of gamma delta T cells are enhanced.
In the liver, tea’s L-theanine gets metabolised to produce ethylamine, which is also produced by disease agents. It seems that this puts the immune system on guard against these pathogens.