Healthy people shouldn't take aspirin to prevent heart disease, researchers say in a new report that casts doubt on recommendations from US health officials.

Medical guidelines currently urge people to take low doses of the drug if they are at high risk of heart disease but have never had any symptoms or if they have already suffered a heart attack.

But the first piece of advice, known as primary prevention, has come under attack from more doctors because aspirin therapy can also be harmful.

"What we need to focus on is lifestyle, smoking cessation, and statin and blood pressure medications," says Dr Kausik Ray, who studies heart disease prevention at St. George's University of London and led the new work. "I don't recommend aspirin."

Ray and his colleagues took a fresh look at nine previous trials of aspirin use in people who had never had chest pain or other symptoms of an ailing heart.

Based on more than 100,000 men and women followed for an average of six years, there was no sign aspirin prevented fatal heart attacks.