High blood pressure, smoking and alcohol abuse are the most dangerous health risks in the world, a major study has shown.

In the space of 20 years, all three have overtaken child hunger to become the leading causes of premature death.

More than nine million people died as a result of high blood pressure in 2010, making it the deadliest single global risk factor. Smoking accounted for 6.3 million deaths and alcohol consumption 4.9 million deaths.

The average trends masked a lot of regional variation, with different parts of the world experiencing different health problems.

The findings form part of a series of papers published online by The Lancet medical journal. Together, they constitute the largest-ever investigation of the global burden of disease, injury and health risks.

Professor Majid Ezzati, a study leader from the School of Public Health at Imperial College London, said: "We're seeing a growing burden of risk factors that lead to chronic diseases in adults, such as cancer, heart disease and diabetes, and a decreasing burden for risks associated with infectious diseases in children."