1. ITV Report

Too much sleep 'could increase risk of stroke' by up to 50%, study suggests

Too much sleep could increase the risk of having a stroke by almost 50 per cent, according to a new study.

People who sleep for more than the average of eight hours a night were at 46 per cent greater risk of stroke - and that figure doubled for older people who regularly slept for lengthy periods of time.

Meanwhile, those whose sleep patterns started out short at the beginning of the study and got longer over time were found to be at four times the risk of those who had a steady sleep pattern.

Research suggests too much sleep is linked to a higher risk of strokes Credit: PA

A team of scientists from the University of Cambridge followed just under 10,000 people aged between 42 and 81 for nearly 10 years for the project.

During that time, 346 of those taking part suffered strokesm, and the team took other factors into account before making the link with sleep patterns.

The next step of research is likely now to focus on trying to determine whether excessive sleep might be a cause or a symptom of future health problems.

It's apparent both from our own participants and the wealth of international data that there's a link between sleeping longer than average and a greater risk of stroke.

What is far less clear, however, is the direction of this link, whether longer sleep is a symptom, an early marker or a cause of cardiovascular problems.

– Yue Leng, University of Cambridge

We need to understand the reasons behind the link between sleep and stroke risk.

What is happening in the body that causes this link? With further research, we may find that excessive sleep proves to be an early indicator of increased stroke risk, particularly among older people.

– Kay-Tee Khaw, senior author

The study was supported by both the Medical Research Council and Cancer Research UK.