Five years is actually not a long time for science to understand a process as complex as the pathways of the oil after a large spill. Some of the impacts of the Deepwater Horizon spill on the marine life and ecosystems of the Gulf of Mexico will only become visible in future years. We use oil products daily.
First the researchers examined the effects of lowering cortisol to below a normal (or baseline) level. Then they compared the effects of low, medium, high, and very high cortisol levels in patients undergoing cardiac surgery, a procedure that causes a lot of inflammation.
When stress becomes chronic, your immune system becomes less sensitive to cortisol, and since inflammation is partly regulated by this hormone, this amplifies your inflammatory response. Inflammation plays a role in most chronic diseases, which is why stress is such a major factor in many chronic health problems: