Few would disagree that eating plenty of fruit is beneficial to health.

But headline-grabbing studies that suggest certain types of fruit can prevent cancer or heart disease have been met with scepticism.

This is because many of the results only apply in test tubes and mice.

Now researchers are about to embark on a three-year study to establish whether such benefits are likely to humans.

Three special berries

The researchers, in Aberdeen, Dundee and Glasgow, will investigate the effect of eating strawberries, raspberries and blackcurrants on heart disease, cancer and stroke.

These fruit are interesting because they contain substances known as antioxidants - which are thought to have a protective effect against many diseases.

Dr Garry Duthie is co-ordinating the study, which is being funded by a £300,000 grant from the Scottish Office.

"The red and blue colour in fruits like strawberries, raspberries and blackcurrants is down to the phenols they contain," he said.

"These are compounds which have a protective antioxidant effect, so we want to examine whether this kind of fruit has a real antioxidant effect in the body."

He said that the UK had one of the worst rates of premature death in the developed world, with heart disease, cancer and stroke the leading causes.