If you're feeling lethargic, downing a cup of tea may give you a lift, and not just because of its caffeine content. New research has found that tea is a potentially rich source of antioxidants...

Antioxidants have been hot property over the last few years. In particular, vitamin E and beta-carotene have been touted as panaceas which could help lower the risk of heart disease, cancer, and possibly reduce the overtraining syndrome in athletes. This is because of their ability to de-activate free radicals - these being potentially dangerous by-products of oxygen metabolism. Anyone who's exercising regularly has an increased load of free radicals to deal with, as more oxygen is processed to help provide the extra energy required. Experimental work has shown that athletes show signs of higher free-radical induced cell damage than their sedentary peers. Free radical damage has been suggested as a contributory factor in the following symptoms of the overtraining syndrome: ...

1 increased red blood cell fragility and breakage
2 low iron stores and exercise anaemias
3 muscle damage
4 lowered immunity and recurrent infections...

Vitamin E and beta-carotene aren't the only food-borne antioxidants. More recently, attention has shifted to polyphenols, naturally occurring chemicals found in plant foods. When tested in the lab, polyphenols have been shown to have outstanding antioxidant and free radical scavenging properties. An excellent source of polyphenols is that favourite pick-you-up - tea. More than 35 per cent of tea (by dry weight) consists of polyphenols...

Researchers in a town perhaps not noted for its tea drinking - Rome - recently completed a study which investigated the anti-oxidant effects of drinking different types of tea. Although polyphenols have been shown to be good antioxidants, there hasn't been much information available on what happens when these are digested. Green tea (popular in China) and black tea (more popular in the West) were compared, with and without milk...

Volunteers were given the different types of tea to drink after an overnight fast, and their total plasma antioxidative capacity was analysed before and after drinking. One large cup of tea was found to lead to an appreciable increase in plasma antioxidative capacity, with both green and black tea having similar effects. However, adding milk to the teas inhibited the effect. This is thought to be because milk proteins bind to polyphenols...

(Serafini et al, 'In vivo antioxidant effect of green and black tea in man', European Journal of Clinical Nutrition, vol. 50, pp28-32, 1996)...

Janet Pidcock