The Cortisol Connection
A bit of psychoneuro-immunology here, I thought it would be a nice topic to know something about as a fresh(ly engineered) batch of weird flu hits at the onset of the cool weather.
Your immune system is regulated by a variety of hormones. Two important ones are cortisol and adrenaline. Both regulate the immune system down (negative feedback loop), but in different ways.
You all know what adrenaline does. It “mobilizes” you, activates the external muscles (sometimes so acutely that they start quivering, like after a huge fright or major offence), it makes your heart-rate go up and enlarges blood vessels to the muscles. Simultaneously it narrows bloodvessels supplying the stomach and various other internal organs (with the notable exception of heart and lungs); when you have to fight or run, you can’t focus on digesting. Neither do you have time to fight viruses, at that moment. People who have a lot of adrenaline reactions also tend to get sick easily as energy is diverted away from the immune system into the peripherals all the time.
Cortisol has a slightly different action. It calms you down and sends the message “all is alright”. At the same time it calms inflammation – interferes with the inflammatory reaction of the immune system and suppresses the activity of immune cells. This makes sense – if you’ve been bitten by a tiger, your wound needs healing, and while some immunity is of course needed, too much inflammation can cause damage and too much immune response can cause the body to attack its own tissues (known as autoimmune diseases, examples are asthma, eczema, psoriasis etc.)
Cortisol is dependent on the mood just as much as adrenaline is. When one feels sorry for oneself, the immune system is suppressed because cortisol is released. Over longer times, this can lead to a chronically weak immune system, and invaders have an easy time. The PLOM disease (“poor little old me”) turns into real disease, making the PLOM even sorrier for himself.
Conversely, those die-hards who just never get sick because they are too busy: Their “no-nonsense” attitude to work and life in general causes suppression of cortisol. Result: A supercharged immune system, so strong it starts attacking the own body. Consequence: Autoimmune diseases.
There you have it. 😀