Test adds weight to ‘slim aid’ green tea

DRINKING green tea may help to slim, a study suggests.

An extract from the tea was found to reduce the amount of starch absorbed from food during meals, scientists found.

Researchers gave 28 subjects aged between 19 and 28 a bowl of cornflakes to eat after fasting 12 hours before the test. They then asked them to eat a wafer – some of which contained green tea extract, while others did not.

The amount of extract given, about 4 grams, was equivalent to drinking ‘several cups of green tea’, the researchers said.

They then tested the breath for the presence of starch.

When starch, also known as carbohydrate, i s broken down during digestion, the amount can be picked up by testing the amount of CO2 on the breath.

The researchers, led by Jaroslaw Walkowia of Poznan University in Poland, found that the single dose of green tea extract decreased starch digestion and absorption compared to the placebo group.

The authors say they are hopeful that green tea extract may become a useful treatment for people suffering from obesity and diabetes.

They write in Nature Scientific Reports: ‘This plant extract is widely available, inexpensive and well tolerated, so it has potential utility for weight control and the treatment of diabetes.’

Green tea has a variety of ingredients that may prevent starch from being absorbed. Key are polyphenols, thought to be involved in reducing starch absorption. But the drink can vary widely on the amount of polyphenols it contains.

Green tea has been studied widely for its health effects. A review in 2012 of 18 studies involving 1,945 people found no significant effect on weight loss.

However, other research has found it can cut cholesterol.

Last year a study by the University of Auckland found that drinking green tea reduced the chances of women on IVF conceiving.

But the NHS Choices website quotes Alison Hornby, a dietician who questions both claims for and against green tea, but says: ‘As a social drink, it appears to be safe in moderate amounts, so lovers of green tea can continue to enjoy it.’