Let's start with an interesting fact: all types of tea, be it green or black, comes from the same plant, Camellia sinensis. The difference only lies in processing and oxidation. So how can one be better than the other you ask? Let's find out.
1. Fluoride content
When it comes to fluoride content both green and black teas score high, while milk tea sadly loses out. Green and black teas are good for your teeth and bones, although black tea has higher fluoride content (0.2-0.5mg as compared to 0.3-0.4mg in green tea). Its best to have your black tea with tap water as it increases the fluoride content up to 0.9mg.
2. Antioxidant content
Yet again green tea and black both have high antioxidant content that helps in preventing cancer, but green is the clear winner over. Milk tea loses again as the milk in it effects the absorption of these antioxidants by your body. Green tea is enriched with a particular type of catechin (flavonoid) called EGCG, which regulates gene activity in cancer cells, and may even prevent cancer growth.
3. Caffeine Content
Benefits for your heart:
Black tea is probably the healthier option if you want to derive cardiovascular benefits from your daily cuppa. While green tea has abundant EGCG which creates a lining along your blood vessels to reduce stress, black tea offers more benefits. Black tea can improve the function of your blood vessels if you suffer from coronary artery disease. Apart from that, both can lower the levels of harmful cholesterol. There's no evidence that supports that milk tea can be beneficial for your heart.
So in the end it's your call to choose black or green tea, whichever works best for you. Try avoiding milk tea as the milk steals away the essential health benefits of tea. Just remember to have no more than 10 cups of green tea a day, and no more than 4 cups of black.