More than 15 million people worldwide suffer a stroke every year, resulting in almost 6 million deaths. Now, new research from Imperial College London in the UK finds that iron deficiency could increase a person's risk of stroke by making the blood sticky.
This is according to a study recently published in the journal PLOS One.
The research team, including Dr. Claire Shovlin, of the National Heart and Lung Institute at Imperial College London, notes that previous research has shown that iron deficiency could be a risk factor for ischemic stroke - when small blood clots interrupt blood flow to the brain - in adults and children.
To investigate why this is the case, the researchers analyzed the iron levels of 497 patients with hereditary hemorrhagic telangiectasia (HHT) - a rare disease than can lead to enlarged blood vessels in the lungs.
The research team explains that healthy blood vessels usually filter out small blood clots before the blood travels to the arteries. But in HHT, the blood vessels can allow small blood clots to make their way to the brain.
Low iron levels 'double stroke risk'
The investigators found that patients with moderately low iron levels (6 micromoles per liter) had double the risk of stroke, compared with patients with iron levels deemed middle of the normal range (7-27 micromoles per liter).
Further investigation revealed that iron deficiency increases the stickiness of platelets - small blood cells. This prompts platelets to stick together, causing clotting.
Commenting on the findings, Dr. Shovlin says:
"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."
She adds that the team plans to investigate whether treating iron deficiency in high-risk patients could reduce their risk of stroke, and specifically, whether this would cause platelets in the blood to 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," adds Dr. Shovlin.
She says the team hopes more studies will investigate the association between sticky platelets and stroke.
The benefits of iron
According to the World Health Organization (WHO), more than 30% of the the world's population suffers from anemia - mainly as a result of iron deficiency.
Lack of iron in the blood can be caused by blood loss, poor diet, or the inability to absorb a sufficient amount of iron from food - a common occurrence in people who suffer from Crohn's disease or celiac disease.
According to the US National Heart, Lung and Blood Institute (NHLBI), the best sources of iron are meat, poultry, fish and iron-fortified foods. A person is more likely to develop iron-deficiency anemia if they do not eat these foods regularly or do not take iron supplements.
Last year, Medical News Today reported on a study suggesting that iron supplementation provides cognitive and physical benefits for anemic children, while other research suggests that iron-rich foods may reduce dementia risk.