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London - A person’s blood group helps determine their risk of heart disease, a study has found.

Researchers claim almost half of Britons with blood group O, the most common blood type, benefit from some natural protection against the illness.

However, they said people from groups A and B are more at risk, while people from AB, the rarest blood group, are the most vulnerable.

The findings, published in the journal Arteriosclerosis, Thrombosis and Vascular Biology, are based on an analysis of two large US health and lifestyle studies.

The Harvard University researchers concluded people with blood group AB were 23 percent more likely to suffer from heart disease.

Group B blood increased the risk by 11 percent, and type A by five percent.

It is thought people with type O blood may benefit from a substance that is thought to assist blood flow and reduce clotting.

Lead researcher Professor Lu Qi, from the Harvard School of Public Health in Boston, said “While people cannot change their blood type, our findings may help physicians better understand who is at risk for developing heart disease.

“It’s good to know your blood type the same way you should know your cholesterol or blood pressure numbers.

“If you know you’re at higher risk, you can reduce the risk by adopting a healthier lifestyle, such as eating right, exercising and not smoking.”

The study compared blood groups and heart disease incidence but did not analyse the complex biological mechanisms involved.

There is evidence that type A blood is associated with higher levels of ‘bad’ type of cholesterol, low density lipoprotein (LDL), which is more likely to fur up the arteries.

AB blood is linked to inflammation, which also plays an important role in artery damage.

People with type O blood may benefit from a substance that is thought to assist blood flow and reduce clotting.

The researchers pointed out the study group was mostly white Caucasian and it is not clear whether the same findings applied to other ethnic groups.

Prof Qi said “It would be interesting to study whether people with different blood types respond differently to lifestyle intervention, such as diet.”

Scientists from Pennsylvania University last year found the same gene that causes people to be blood group ‘O’ gives them some protection against heart attack.

But experts warn that while blood type O may offer some protection from heart trouble, blood type alone will not compensate for other factors that are linked to cardiovascular disease.

Other research found blood group O patients may be at greater risk for bleeding and blood transfusions after heart surgery.

Patients with AB blood type are 20 percent less likely to die after heart bypass surgery than those with A, B or O blood types, said Duke University Medical Centre researchers.

Doireann Maddock, Senior Cardiac Nurse at the British Heart Foundation, said “While these findings are certainly interesting we’ll need more research to draw any firm conclusions about blood type and its role in heart disease risk.

“Nobody can influence what type of blood they are born with but a healthy lifestyle is something everybody can have an influence over. Eating healthily, getting active and stopping smoking are the types of things you should be worrying about, not your blood type.” - Daily Mail