Researchers have found that fat around our arteries may play an important role in keeping those blood vessels healthy. The fat known as perivascular adipose tissue or PVAT helps arteries do what scientists call stress relax or let go of muscular tension while under constant strain. This is similar to the bladder which expands to accommodate more liquid while at the same time keeping it from spilling out. In our study PVAT reduced the tension that blood vessels experience when stretched and that's a good thing because the vessel then expends less energy. It's not under as much stress said