Researchers at the University of Murcia in Spain (UMU) and the John Innes Center (JIC) in Norwich, England have shown that a compound called EGCG in green tea prevents cancer cells from growing by binding to a specific enzyme.
"We have shown for the first time that EGCG, which is present in green tea at relatively high concentrations, inhibits the enzyme dihydrofolate reductase (DHFR), which is a recognized, established target for anti-cancer drugs, " Professor Roger Thorneley, of JIC, told Reuters.
EGCG binds strongly to DHFR, which is essential in both healthy and cancerous cells. But it does not bind as tightly as methotrexate, so its side effects on healthy cells could be less severe than those of the drug.
The findings could also explain why women who drink large amounts of green tea around the time they conceive and early in their pregnancy may have an increased risk of having a child with spina bifida or other neural tube disorders.
Women are advised to take supplements of folic acid because it protects against spina bifida. But large amounts of green tea could decrease the effectiveness of folic acid.
"This enzyme, (DHFR), is the one folic acid supplements are given for. Folic acid deficiency leads to neural tube development defects," Thorneley added.
Steve - Fascinating stuff. More research must to be done, but it seems that in this case "too much of a good thing" can be a bad thing.