Pregnant women would be wise to limit the amount of green tea they drink during pregnancy, and should be careful about taking any green tea supplements. Green tea is rich in antioxidants, and has a host of health benefits relating to dental health, blood sugar levels, cholesterol, and weight loss. But researchers have found, whilst examining the active constituent of green tea, the epigallocatechins, or EGCG for short, that it may affect the way the body uses folate. Folate is important for pregnant women as it prevents neural tube birth defects in babies.
The problem of green tea during pregnancy is that the EGCG molecules are structurally similar to a compound called methotrexate. Methotrexate is able to kill cancer cells by chemically bonding with an enzyme in the body called enzyme dihydrofolate reductase (DHFR). Healthy people have this enzyme also – it is part of what is called the folate pathway, which is the pathway, or steps, the body takes to transform nutrients like folate into something that can be used to support its normal functions.
But this chemical similarity means that the EGCG in green tea also binds with the enzyme DHFR, and when it does...