People who are deficient in iron may have an increased risk of suffering a stroke, a new study has found.

The risk refers to ischaemic strokes, which are caused by a sudden blockage in the blood vessels supplying blood to the brain. Up to 90% of strokes are ischaemic.

According to UK scientists, recent studies have suggested that iron deficiency, which affects some two billion people around the world, may be a risk factor for this type of stroke. However why this is has remained unclear, so they decided to investigate further.

They found that iron deficiency may increase the risk of a stroke by making the blood more sticky. Specifically, the stickiness of platelets (small blood cells), which begin the process of blood clotting when they stick together, increases if a person is deficient in iron.

While a link between sticky platelets and iron deficiency was discovered decades ago, its role was not considered important until now.

The study, which involved almost 500 patients, found that having even moderately low levels of iron appeared to double the risk of an ischaemic stroke compared to having normal levels.

"Since platelets in the blood stick together more if you are short of iron, we think this may explain why being short of iron can lead to strokes, though much more research will be needed to prove this link," noted Dr Claire Shovlin of Imperial College London.

She said that the next step will be ‘to test whether we can reduce high-risk patients' chances of having a stroke by treating their iron deficiency'.

"We will be able to look at whether their platelets become less sticky. There are many additional steps from a clot blocking a blood vessel to the final stroke developing, so it is still unclear just how important sticky platelets are to the overall process. We would certainly encourage more studies to investigate this link," she added.

Details of these findings are published in the journal, PLOS ONE.