This is packed full of antioxidants and while it does contain caffeine, the effect is buffered by the amino acid, l-theanine. Green tea has been shown to support cardiovascular health, help reduce the risk of certain cancers and assist with concentration. support our liver and estrogen metabolism. They also contain sulforaphane, an antioxidant and stimulator of natural detoxifying enzymes. Sulforaphane may help reduce the risk of breast and bladder cancers.