Kate Cornell was diagnosed with type 2 diabetes in June of 2005. Since then, she has controlled diabetes through dietary changes, exercise, and, more recently, metformin. She shares her experiences and lessons learned here and on her blog, kates-sweet-success.blogspot.com, which was named as one of the top diabetes blogs for 2015 by Healthline.com.

A study has shown that drinking coffee and green tea may reduce the risk of developing type 2 diabetes. There are also many claims being made that drinking green tea—or taking a green tea supplement—has many health benefits. But we need to be careful when we choose how we are consuming the beneficial green tea.

Researchers at Consumerlab.com conducted a study of 26 types of beverages containing green tea and various supplements containing ECGC (epigallocatechin gallate, the antioxidant ingredient in green tea) and found that “amounts of the beneficial antioxidant varied wildly.”

Not only that, but they found that many of the green tea beverages were mostly sugar water. That doesn’t sound like something we should be drinking!

The solution: brew your own tea

As with any claim of health benefit or “cure” for diabetes, it’s important that you pay attention to the nutrition label. Brewing your own green tea (from tea bags) is the best way to ensure that you’re not consuming unwanted ingredients like added sugars.

A supplemental plan

If you decide to take a supplement, pay attention to what is in it. There is no official dosage recommended, so do your research. Remember, the FDA doesn’t approve supplements!

Bottom line: Adding a cup or two of green tea to your day is a good way to add some beneficial antioxidants to your diet, but don’t fall into the trap of buying green tea beverages that may contain ingredients that will make your diabetes control more difficult.