#Caffeine content in green tea cracked#

So they didn't account for factors that could alter the results, such as family history, family wealth, diet and so on. They are mostly low-grade observational studies - not proper double-blind controlled studies. And just to round things off, green tea is also claimed to protect against osteoporosis and dental caries.īut then, many of these supposedly good chemicals are found in fruit and vegetables, and in cocoa and wine.īut when you look closely at the studies, they are overwhelmingly not human studies - rather, they're mostly either animal studies or cell-line studies on the laboratory bench.Īnd from a statistical point of view, the relatively few human studies are, to put it kindly, sub-optimal or 'not very rigorous'. Black tea has about 55 mg of caffeine, while green tea has about 20 milligrams.īut it's mostly the phenolic compounds that are claimed to be the basis of all those amazing health effects - a treatment for headaches, various body aches and pains, and depression, as well as a protector again cancers of the stomach, colon, breast, ovary, bladder and prostate. You've heard of caffeine in coffee - an average cup has about 100 milligrams. The difference is that green tea has no oxidised phenolic compounds, while black tea has about 25 per cent. So the dried leaves of each contain roughly the same levels of proteins and amino acids (about 19 per cent by weight), fibre and other carbohydrates (33 per cent), fats (7 per cent), pigments (2 per cent) and minerals (5 per cent). However, the black teas do go through an oxidising process, and so they contain 'oxidised phenolic compounds' such as theaflavins and thearubigins, and the final liquid is darker in colour. The green tea leaves do not go through an oxidising process, so the leaves contain so-called 'non-oxidised phenolic compounds', such as catechins, and the teas are lighter in colour.

The difference between green and black tea is firstly that they tend to come from different varieties of the tea plant, Camelia sinesis, and secondly, how they are processed. Only very small quantities of white tea and oolong tea are drunk. Green teas makes up most of the rest of the tea that's enjoyed, and it's widely drunk in China, Korea, Japan and Morocco. Black tea is popular in Europe, North America and North Africa, and makes up about 80 per cent of all tea produced and consumed. There are a few different types of tea around.

#Caffeine content in green tea cracked#

But not all green tea is what it's cracked up to be - and in some cases, it can harm you. There's one specific variety of tea called 'green tea', for which many marvelous claims are made. It can give you a 'lift', without the edginess that sometimes accompanies a cup of coffee.

That lovely hot beverage, tea, is one of the most popular liquids regularly consumed by humans. Audio: The truth about green tea (Science Online Audio).