Tea's good, but hold the milk

十月 13, 2000

The British may always put the kettle on when faced with a crisis, yet a study suggests that our drinking habits may deprive us of tea's most beneficial properties.

Scientists have found that regular doses of black tea - the type favoured in Europe - boost the body's levels of antioxidants, chemicals that are thought to fend off tumours, heart disease and strokes.

Adding milk to the drink, however, seems to negate these benefits, says the study.

The research was done by Simon Langley-Evans, senior lecturer in human nutrition at University College Northampton, and was published in the latest issue of the International Journal of Food Science and Nutrition. He said: "The findings suggest that black tea drinking could indeed reduce risk of major disease states through an antioxidant mechanism but that the typical British method of tea preparation could nullify the effect."

Epidemiological surveys have indicated that individuals with high tea intakes have a significantly lower risk of disease.

This is thought to be due to polyphenolic flavonoid compounds such as catechin and epicatechin. Tea is known to be a particularly rich source of these antioxidant chemicals, which can be absorbed across the gut into the blood stream, where they can mop up damaging free radicals that can harm cells, cause DNA to mutate and assist plaques to form in arteries.

Recent research has suggested that the green tea - which is prepared in a different way from black tea and is preferred in East Asia - raises antioxidant levels. The study by Langley-Evans provides the clearest indication yet of similar health-giving properties for black tea.

In the experiment, nine volunteers drank six mugs of tea at hourly intervals. Their blood was sampled at 9am, just before their first cuppa, again at midday and finally at 3pm, an hour after the final drink.

Each volunteer took part in three separate trials - one with black tea, a second with milk added and a third with no drink at all.

Langley-Evans found that drinking tea without milk led to a rapid and pronounced boost in antioxidant levels in a person's blood. At midday, levels had risen by 65 per cent, and they hit 76 per cent by 3pm.

When milk was added to the tea, there was no rise in the blood's antioxidant capacity.

The cause of this effect is not yet known, though Langley-Evans believes the antioxidants may bind to the complex mix of fats and proteins in milk.

An untested alternative might be to drink lemon tea.


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