Which green tea tastes the best is a matter of personal preference. However, some types of green tea may be healthier than others. Consider the antioxidant content as well as potential contamination with pesticide residues and heavy metals when choosing which tea to purchase. Brewed organic green teas from Sri Lanka or Japan may be among the best choices.
Brewed Versus Bottled
You'll get more beneficial antioxidants from your green tea if you choose brewed tea over bottled tea. A study presented at the 240th National Meeting of the American Chemical Society in 2010 found that 1 cup of brewed green tea contains as much of a type of antioxidants called polyphenols as 20 bottles of tea. The processing methods used to prepare bottled green tea lowers the antioxidant content.
Country of Origin
In a study published in the "Journal of Toxicology" in 2013, most of the green teas tested contained at least some amount of heavy metals, such as lead, arsenic, cadmium and aluminum. Organic green teas tended to contain higher amounts of lead, aluminum and cadmium than regular green tea, but lower levels of arsenic. Both standard and organic tea from China were high in aluminum, and the organic version was also high in lead, so you may be better off choosing tea from another country. Organic green tea from Sri Lanka was low in all four of these contaminants, and organic green tea from Japan had only moderate levels. Brew your green tea for the shortest recommended time, as longer brewing times lead to more heavy metals leaching into your tea.
Organic Versus Conventional
To limit your intake of pesticide residues, choose organic teas. For these teas to be labeled as organic, they can't have been grown with the use of pesticides. However, in a study published in the "Journal of AOAC International" in July 2010, none of the teas tested had pesticide residues higher than those allowed by either Japan or the European Union, so this may not be a big issue.
Caffeinated Versus Decaffeinated
Sometimes you might not want the extra dose of caffeine from regular green tea. Just be aware that reaching for a decaffeinated version of green tea will lower the amount of beneficial antioxidants you get per cup. A study published in "Nutrition and Cancer" in 2003 found that decaffeinated teas contained between 4.6 and 39 milligrams of a type of antioxidant called flavanols per gram of tea compared to the 21.2 to 103.2 milligrams per gram found in regular caffeinated green teas. Once again, the extra processing involved can decrease the antioxidant content.