Being fat is sometimes good for your heart

Coronary heart disease develops when the heart's blood supply is blocked or interrupted by a build-up of fatty substances in the coronary arteries. File photo

Being obese could help improve chances of survival after a heart attack because excess fat appears to fight heart disease, a British study has shown.

Scientists were puzzled by the fact that the most overweight people lived longer after a heart attack than those with a healthy Body Mass Index - a phenomenon dubbed "the obesity paradox".

A study of tissue from patients undergoing heart surgery found that fat surrounding damaged blood vessels releases chemicals that start to battle heart disease. These chemicals are both anti-inflammatory, minimising swelling, and anti-oxidant, targeting the damaging process itself.

Professor Charalambos Antoniades, associate professor of cardiovascular medicine at the University of Oxford, said: "Fat has a bad reputation, but we're learning more and more about how and why certain types of fat in the body are actually essential for good heart health."

Coronary heart disease develops when the heart's blood supply is blocked or interrupted by a build-up of fatty substances in the coronary arteries. Over time the walls of the arteries can become furred up with fatty deposits, restricting blood flow and harming the heart's ability to pump.

It was thought that all fat was bad for people with heart disease, but it seems that over a certain level it starts to have a protective effect. So though obese people are more likely to have heart disease or a heart attack, they are also more likely to survive.

"These findings are an important step towards a treatment that ensures this fat stays onside throughout our lives to help prevent heart disease," Antoniades said.

The team are now looking at how these processes can be weakened if the fat is unhealthy, as can be the case if a person has type 2 diabetes. They are hoping to develop treatments to reverse this so this fat has a positive impact all the time.

Professor Jeremy Pearson, associate medical director at the British Heart Foundation, which helped fund the research, said: "There's still a huge amount we don't know about how heart disease develops . this high-quality research using human tissue has provided new perspectives on the roles of fat in heart disease and has implications for future treatment."