Orange and grapefruits contain chemicals that can keep arteries healthy and prevent heart attack, says a study. It suggests that eating at least one orange a day could keep cardiac disease away.

The citrus fruits contain the compounds flavanones that reduced blood cholesterol levels by 20-25 percent during a study on rats, reported the online edition of Daily Mail.

The researchers at the Hebrew University in Jerusalem reported to Chemical and Industry magazine that flavanones not only reduced levels of bad LDL cholesterol but also increased the ratio of good HDL cholesterol.

The findings could help explain why those who live in the Mediterranean tend to live longer and have lower levels of heart disease than those in northern Europe.

It is suggested that those with high cholesterol try eating a diet rich in citrus fruits as a first alternative drugs such as statins.

It is already known that grapefruit consumption can have an effect on cholesterol levels by changing the way the liver functions - so much so that doctors warn patients who are prescribed statins not to eat grapefruit because it can increase the effect of the drugs.