Previously considered a health menace, the fat surrounding our hearts can have a protective quality that actually fights heart disease, University of Oxford researchers have found.
In the study funded by the British Heart Foundation, researchers intended to support what earlier studies on animals suggested: that fat around the heart harmed heart function. They were surprised to find the opposite.
“When our vessels are being attacked by harmful products of metabolism, called ‘free radicals,’ they send SOS messages to the neighboring fat that surrounds them,” said Charalambos Antoniades, associate professor of cardiovascular medicine at the University of Oxford and lead author of the study. “When that fat is healthy, it responds by sending back help to the vessel, producing more protective chemicals.”
Fat won’t send back those protective antioxidant chemicals that reduce inflammation and reduce risk of heart attack, however, if the fat is unhealthy, Antoniades said, as conditions such as insulin resistance and diabetes limit fat’s protective role.
“When unhealthy fat receives these signals from the vessels, it doesn’t respond, or it sends harmful products that make things even worse,” he explained.
Many assume that Antoniades’s research supports the “obesity paradox,” that people with body-mass indexes indicating obesity are more likely than thinner people to survive a heart attack.
But before you load up on double cheeseburgers, take note: “BMI is an index that doesn’t take into account the distribution of fat in our bodies,” he said. In other words, it isn’t just how much fat you have that matters but where it is; a person with a low BMI but a high percentage of belly fat isn’t necessarily healthier, for example.
“We’re not talking about fat as a nutrient but fat as tissue type in our body,” Antoniades stressed. When it comes to diet, “fat intake is generally harmful and should be avoided.” But certainly healthy sources of fat, such as fish and nuts, are far superior to red meat and high-fat dairy.
Researchers hope their findings will help them figure out how to “reprogram” unhealthy fat surrounding the heart vessels so it will send out the same helpful responses as healthy fat.
Virginia Pelley is a freelance reporter for the Chicago Tribune.
