GRANDMOTHER did know best. Scientists have established that tea left to brew in a pot is better for your health.

The traditional way of making a cuppa releases more cancer-fighting chemicals than simply dunking a tea bag in a mug of boiling water.

Researchers at the Rowett Research Institute in Aberdeen found that the concentration of antioxidants, which soak up damaging free radicals linked to cancer and heart disease, reaches its peak after five minutes’ brewing in a pot.

The scientists tested levels of polyphenols – antioxidants naturally occurring in plants – in the blood of volunteers who drank black tea brewed for up to 10 minutes.

They found that blood antioxidant levels were 60% higher among the volunteers who drank tea that had been brewed for five minutes than those who consumed a one-minute infusion. The difference between a three and five-minute brew was 30%.

Within an hour of drinking the five-minute infusion, the level of antioxidants in volunteers’ bloodstreams rose by up to 45%.

Leaving tea to brew for longer than five minutes yielded no extra health benefits. The researchers also found that adding milk to a cuppa had no effect on its cancer-fighting properties.

“We have established that the length of time you infuse the tea before you drink it is important,” said Garry Duthie, professor of molecular nutrition at the Rowett Research Institute and co-author of the study, published in the Journal of Agricultural and Food Chemistry. “These days, people tend to dunk the tea bag, so they are consuming fewer of these potentially beneficial chemicals than they did in the past.”

Research published earlier this year in the European Journal of Cancer Prevention suggested that drinking two cups of tea a day could cut the risk of developing skin cancer by up to 65%.

A review of published studies into the benefits of drinking tea, conducted by public health nutritionists at King’s College London and published last year, concluded that drinking three or four cups a day could cut the risk of suffering a heart attack. The study also suggested that drinking tea could strengthen bones and protect against tooth decay.

Meanwhile, scientists at Harvard medical school have concluded that drinking tea can reduce the risk of four of the major health problems: stroke, heart failure, cancer and diabetes.

Britain is the world’s second biggest consumer of tea, beaten only by the Republic of Ireland. Each day Britons drink 165m cups. However, consumption has declined as more people have switched to coffee.

“This research proves your old daily cuppa is doing you a power of good,” said Bill Gorman, executive chairman of the UK Tea Council.

“The longer you brew, the more value you are going to get. If you are a 40-second dunker you will get some value but not as much if you brew for four or five minutes.”

Ed Yong, Cancer Research UK’s health information officer, said: “Until more research is done, we would advise people simply to enjoy drinking tea.”

Explore Health

• Expert Advice

• Health Features

• Mental Health

• Alternative Medicine

• Child Health

• Health Club