Vegetarians have a higher risk of stroke than those who enjoy a good steak, a major study has found. The Oxford University research, published in the BMJ, suggests that a meat-free diet may cause lower blood levels of total cholesterol, and reduce intake of vitamins which protect against such attacks.

The study, which tracked almost 50,000 Britons for 18 years, found vegetarians and vegans had a 20 per cent higher risk of stroke than those who eat meat.

Most of the increased risk was due to a higher rate of hemorrhagic stroke. These occur when blood from an artery starts bleeding into the brain.

Vegetarians and vegans in the study had lower circulating cholesterol and lower levels of key nutrients - such as vitamin B12 and D - which could explain the link, researchers said.

However, those avoiding meat had a significantly lower chance of heart attacks, the study found.

Vegetarians were found to have a 22 per cent lower risk of heart disease, in total, while those eating fish but no meat had a 13 per cent lower risk. Experts said some of the difference might be linked to lower weight, blood pressure, and fewer cases of conditions like diabetes among those shunning meat.