The vagus nerve is actually a pair of nerves that connects the brain to most of the internal organs, and has a calming influence on the heart and digestive system. It has been called the superhighway between the brain and the gut, as it sends information in both directions rapidly and directly. Some of these signals affect how well you digest food and how hungry you feel; some communicate important information about the health of your digestive tract.
Acetylcholine messengers on the superhighway
The vagus nerve uses neurotransmitters called acetylcholine as messengers to relay information along its superhighway. So, for example, if there is inflammation in the lining of the intestines, acetylcholine will tell the brain. The brain will hopefully register that this is not an ideal long term situation for the gut: nutrients may not be absorbed so well, and the gut lining may become so damaged that it can no longer efficiently prevent toxins from entering the bloodstream (“leaky gut”). The vagus nerve will then send more acetylcholine with soothing, anti-inflammatory instructions from the brain back to the gut.1
Foods for making acetylcholine
Nutritionally it may be wise to help the work of the vagus nerve by providing foods that contain choline, so that you can make more acetylcholine. Egg yolks are good sources of choline if they are soft – or even better, raw, as you would find, for example, in fresh, homemade mayonnaise. The more you cook egg yolks, the less choline they will contain. Offal is also a good source, such as liver and kidneys. In either case, I would recommend an organic, pasture-fed source for cleanliness and quality. For a vegan option, lecithin granules (usually from soya, occasionally from sunflower seeds) are great to sprinkle onto foods and into smoothies.
You can also ensure an adequate intake of L-acetyl carnitine (in meat), vitamin B5 (in broccoli, chard, squash, sunflower seeds and eggs) and alpha lipoic acid (from red meat, offal or brewers’ yeast) to help with acetylcholine production. Vegetarian and those who eat low amounts of meat can synthesise L-acetyl carnitine from 2 amino acids: lysine and methionine – fish and spirulina may be useful here.
- Borovikova, Lyudmila V., et al. “Vagus nerve stimulation attenuates the systemic inflammatory response to endotoxin.”Nature 6785 (2000): 458-462.