Vagus nerve stimulation: Shock tactics set to shake up immunology

I am such a huge cynic of this. This involves stimulating the parasympathetic nervous system, which is the antagonist, so to speak, of the sympathetic nervous system.

A few years ago a company called Ardian had a minimally-invasive system called renal redervation for destroying the sympathetic nerves to the kidneys, in the hope that it would cure high blood pressure. Initial unblinded single armed trials were favourable, and so Ardian made $1,000,000,000 selling to Medtronic.

Lo and behold, in the double-blinded randomised trial, renal denervation did absolutely nothing.

Renal denervation was fuelled by optimism and bluff about the role for these nervous systems in disease. Shock horror, however, when manually altering them with a blunt tool such as ablation (in the case of renal denervation) or stimulation (the example here), doesn't actually help.

The whole saga of renal denervation was one of the greatest examples of bad science and optimism getting ahead of us. This is a nice editorial: http://jamesphoward.com/papers/RDE.pdf

Can't you stimulate the vagus nerve with a big meal or belly breathing? All this time I thought people advising belly breathing were just a bunch of dirty hippies who were afraid of the doctor. I wonder if there's something special about HOW this stimulates the vagus nerve or if it's any stimulation at all.

> Exposure to acetylcholine, however, prevents macrophages from producing the inflammatory protein

But aren't there better ways to increase acetylcholine than stimulating the vagus nerve?