Men are being asked to drink a litre of beer a day - all in the name of medical research.

The EU-funded research is looking into a possible link between a vitamin called folate - found in beer - and a reduced risk of heart disease.

However, potential volunteers may be put off by one catch - the supplied beer is non-alcoholic.

The experiment is being carried out at the Institute of Food Research in Norwich.

Serious science

Project leader Dr Paul Finglas said people suffering from heart disease generally have high levels of a chemical called homocysteine - which has been linked to blocked arteries and heart disease.

A high intake of folate vitamins is associated with low homocysteine levels, so scientists are keen to investigate it as a way of reducing heart risk for men.

The 80 men who drink the German beer will be tested to see if their folate levels increase and homocysteine levels decrease.

However, Dr Finglas denied he was being a spoilsport by cutting out the alcohol - and suggested that alcoholic beer was unlikely to ever be the ideal way of delivering folate to the body.

He said: "It would be difficult to do a study where we are giving people alcoholic beer because people have to get on with their lives.

"Also alcohol impairs folate absorption in the body."

Birth defects

Other scientists in Europe are carrying out research using folate-rich foods popular in their countries, such as gazpacho soup in Spain - it contains tomatoes and peppers - and rye bread in Finland.

There is already evidence that moderate beer drinking - with alcohol included - may have a noticeable effect on homocysteine levels.

However, binge drinking is still not recommended by doctors.

Folate - or folic acid - is recommended for women trying for a baby because, if levels are up during early pregnancy, it offers protection against babies with "neural tube defects" such as spina bifida.

However, the Food Standards Agency decided recently to put off the fortification of flour for bread with the vitamin, fearing that high folate levels could mask other vitamin deficiencies in older people.