The world loves a cuppa. Even though it takes just a few grams for a brew-up, some 3m tonnes of tea are consumed every year. And tea can be good for you, as it contains compounds that help to lower cholesterol and reduce the risk of cardiovascular disease. But there is a downside. Tea contains caffeine which, although it improves mental alertness, can also cause anxiety, insomnia and other problems.
Sipping decaffeinated tea can help, but there are drawbacks to this, too. Stripping away caffeine from tea involves either immersing the leaves in carbon dioxide at extremely high pressure or treating the leaves with searing hot water. Although this will get rid of most of the caffeine, it can cause collateral damage to some of the fragile compounds that give tea its benefits. And, as with decaf coffee, which is treated in similar ways, many people argue that it also spoils the flavour.
What would be agreeable is a tea plant that provides all the taste and goodness but with little or none of the caffeine. Liang Chen and Ji-Qiang Jin of the Tea Research Institute of the Chinese Academy of Agricultural