Q. I've heard black tea could improve attention span, so is it worth letting my kids (aged seven and 10) drink it, or are they too young?

A: Dr Carrie Ruxton of the Tea Advisory Panel says: "There is, indeed, good evidence from adult studies that drinking tea improves alertness, mood, short-term memory and reaction time. This is because tea contains a small amount of caffeine (40-50mg per cup), which is around half that provided by a cup of coffee. As yet, there has been no research in children, so we don't know if these benefits are the same in all ages. However, tea is a healthy drink for all school-aged children, as it's naturally sugar-free and contains special plant compounds, called polyphenols, which are beneficial for health maintenance.

Adding plenty of milk to unsweetened tea provides a source of calcium and is healthier for teeth than acidic fruit juices or sugar-containing soft drinks. Some studies have also found that tea has anti-microbial properties, meaning that it could fight the bacteria in the mouth which contribute to dental decay."