After months puzzling over this, he finally hit upon the idea that the brain might be using the nervous system – specifically the vagus nerve – to tell the spleen to switch off inflammation everywhere.
It was an extraordinary idea – if Tracey was right, inflammation in body tissues was being directly regulated by the brain.
Communication between the immune system’s specialist cells in our organs and bloodstream and the electrical connections of the nervous system had been considered impossible. Now Tracey was apparently discovering that the two systems were intricately linked.
…Operating far below the level of our conscious minds, the vagus nerve is vital for keeping our bodies healthy. It is an essential part of the parasympathetic nervous system, which is responsible for calming organs after the stressed ‘fight-or-flight’ adrenaline response to danger. Not all vagus nerves are the same, however: some people have stronger vagus activity, which means their bodies can relax faster after a stress.
…Tak suspects that patients will continue to need vagal nerve stimulation for life. But unlike the drugs, which work by preventing production of immune cells and proteins such as TNF, vagal nerve stimulation seems to restore the body’s natural balance. It reduces the over-production of TNF that causes chronic inflammation but does not affect healthy immune function, so the body can respond normally to infection.
… Low vagal tone is associated with a range of health risks, whereas people with high vagal tone are not just healthier, they’re also socially and psychologically stronger – better able to concentrate and remember things, happier and less likely to be depressed, more empathetic and more likely to have close friendships.
…The implications of being able to simply and cheaply improve vagal tone, and so relieve major public health burdens such as cardiovascular conditions and diabetes, are enormous. It has the potential to completely change how we view disease.
…However the technology develops, our understanding of how the body manages disease has changed for ever. “It’s become increasingly clear that we can’t see organ systems in isolation, like we did in the past,” says Paul-Peter Tak. “We just looked at the immune system and therefore we have medicines that target the immune system.
“But it’s very clear that the human is one entity: mind and body are one. It sounds logical [or to some of us: mindblowingly obvious] but it’s not how we looked at it before. We didn’t have the science to agree with what may seem intuitive. Now we have new data and new insights.”