Medication routinely prescribed for common complaints such as allergies, heart disease and Parkinson's has been linked to an increase in the risk of strokes.

Researchers at Aberdeen University found that patients treated with drugs with 'anticholinergic' side effects are six times more likely to have a stroke.

The study, published this week in the International Journal of Epidemiology, looked at 22,000 people.

It's the largest investigation of its kind to be carried out in the area.

Lead author of the study, Dr David Gamble, said: "A number of plausible mechanisms exist within the literature to explain our findings.

"Medicines with anticholinergic effects have been shown to affect inflammation, which is important in the period immediately after a stroke, produce rapid and irregular heart rhythms and interfere with the body's ability to regulate heart rate and blood pressure, which has been shown to be protective in stroke.

"It is possible that diminishing these protective effects with anticholinergic drugs can make people more vulnerable to stroke"