Well I don't know about any research behind that article, and his conclusions may be true but these sentences....
"Those of us who rage a lot have more health problems than people who practice containing their anger. The popular psychological theories that suggested a need to express anger for mental and physical health reasons have been proven false when put under the microscope of scientific research. The more we scream and yell, the worse our health gets, the more prone we are to heart attacks and the worse our rage problem becomes.".....
look like the usual confusion between cause and effect. If it is true that angry people have more health problems is this because expressing anger damages health or because health problems affect mood?

The way the popular press reports science makes me...maybe not angry, but certainly amazed, irritated, exasperated.