Fat around your belly is bad for your heart, but it turns out that fat around your heart may be even more dangerous. Researchers divided 160 people ages 55 to 74 into four groups based on the amount of pericardial fat (fat deposits around the heart) they had. What they found: People with the highest pericardial fat levels were nearly five times more likely to have calcified coronary plaque, or atherosclerosis, than those with the lowest levels. Pericardial fat secretes more inflammatory cytokines, proteins that regulate inflammation, than fat under the skin. Authors of the study, published in the journal Obesity, say that constant exposure to these proteins may speed plaque development.