Pregnant women and women who are breastfeeding should also avoid drinking green tea. 

This is because the caffeine in green tea can cross the placenta and enter breast milk. 

Green tea may also increase the risk of osteoporosis, a condition that causes bones to become weak and brittle. 

This is because green tea contains compounds that can interfere with the absorption of calcium. 

Green tea extract supplements have been linked to rare cases of liver damage. 

It's important to talk to your doctor before taking any green tea supplements. 

Overall, green tea is a safe beverage for most people to consume in moderation.  

However, it's important to be aware of the potential side effects and risks before drinking green tea, especially if you have any underlying health conditions or are taking any medications. 

If you're concerned about the potential risks of green tea, talk to your doctor.