High fat foods stimulate the vagus nerve

[Renaissance]

Here's a couple of articles discussing how fat stimulates the vagus nerve and reduces inflammation.

http://www.medicalnewstoday.com/articles/31846.php

"Take two cheeseburgers and call me in the morning," may sound like far-fetched medical advice. After all, high fat foods can worsen blockages in blood vessels. But a new study in the October 17 issue of The Journal of Experimental Medicine shows that high fat foods can, at least in the gut, soothe inflammation. This action may stop immune cells from attacking food as a foreign invader.

Eating -- particularly eating fat-rich foods -- causes cells in the small intestine to produce a hormone called cholecystokinin, or CCK. CCK stimulates digestion and gut peristalsis (the motion that propels food along the digestive tract), and also triggers satiation -- the full feeling that prompts you to stop eating.

The study by Luyer and colleagues shows that fat-induced CCK can also dampen inflammation in the gut, as rats fed a high-fat diet were protected against lethal bacteria-induced shock whereas those fed a low-fat diet were not. CCK sent signals to the brain through the vagus nerve, the nerve that provides the electrical regulation for many internal organs, including the gut and the heart. In response to CCK, vagus nerve endings in the gut released a neurotransmitter called acetylcholine. Acetylcholine then bound to proteins on immune cells and turned the cells off.

The authors think this pathway might explain why the immune system doesn't react to food proteins and normal gut bacteria as if they were foreign invaders. They also suggest that triggering this fat-driven chain of events in patients might provide a way to reduce inflammatory complications after surgery.

Nickey Henry
henryn@rockefeller.edu
212-327-8366

This one expands on the above:

http://jem.rupress.org/content/202/8/1014.1.full

Journal of Experimental Medicine

A study on page 1023 reveals a potential benefit of much-maligned high fat foods. According to Luyer and colleagues, the same hormone that makes you feel full after a fatty meal might also prevent immune cells from mistakenly attacking food proteins as if they were foreign invaders.Eating—particularly eating fat-rich foods—triggers the production of a hormone called cholecystokinin (CCK) by cells that line the small intestine. CCK binds to its receptor on cells in the gut, pancreas, and central nervous system (CNS), thus stimulating digestive functions, including gut peristalsis and insulin release, and triggering satiation. Luyer and his colleagues recently showed that dietary fat also blunts the inflammatory response in a rat model of hemorrhagic shock.

The new study connects CCK to a recently identified antiinflammatory pathway that is controlled by the vagus nerve. This pathway—dubbed the cholinergic antiinflammatory pathway—is mediated by the neurotransmitter acetylcholine, which is released from vagus nerve endings upon stimulation. Acetylcholine binds to nicotinic receptors on macrophages, thus inhibiting the synthesis and release of inflammatory cytokines such as TNF and interleukin (IL)-6.

Luyer et al. now show that the antiinflammatory effect of fat consumption in the rat model of hemorrhagic shock requires both CCK and the vagus nerve, as blocking CCK or severing the vagus nerve abolished this effect. With the vagus nerve intact, fat-induced CCK inhibited the production of circulating TNF and IL-6 and reduced gut permeability. Blocking nicotinic receptors also eliminated the antiinflammatory effects of dietary fat, thus solidifying the connection between fat-induced CCK and the cholinergic antiinflammatory pathway.

The authors think that this pathway might be important in suppressing gut inflammation in response to food proteins and normal gut bacteria, which immune cells might otherwise regard as foreign invaders. They also suggest that this pathway could potentially be targeted in patients as a way to reduce inflammatory complications after surgery.

http://jem.rupress.org/content/202/8/1023.full
Abstract (full paper at the above link)

The immune system in vertebrates senses exogenous and endogenous danger signals by way of complex cellular and humoral processes, and responds with an inflammatory reaction to combat putative attacks. A strong protective immunity is imperative to prevent invasion of pathogens; however, equivalent responses to commensal flora and dietary components in the intestine have to be avoided. The autonomic nervous system plays an important role in sensing luminal contents in the gut by way of hard-wired connections and chemical messengers, such as cholecystokinin (CCK). Here, we report that ingestion of dietary fat stimulates CCK receptors, and leads to attenuation of the inflammatory response by way of the efferent vagus nerve and nicotinic receptors. Vagotomy and administration of antagonists for CCK and nicotinic receptors significantly blunted the inhibitory effect of high-fat enteral nutrition on hemorrhagic shock-induced tumor necrosis factor-α and interleukin-6 release (P < 0.05). Furthermore, the protective effect of high-fat enteral nutrition on inflammation-induced intestinal permeability was abrogated by vagotomy and administration of antagonists for CCK and nicotinic receptors. These data reveal a novel neuroimmunologic pathway, controlled by nutrition, that may help to explain the intestinal hyporesponsiveness to dietary antigens, and shed new light on the functionality of nutrition.

 

[shijing]

I never considered that these two things -- fat consumption and the role of the vagus nerve -- could be directly tied together, even though we advocate both independently. Excellent piece of the puzzle, Shane -- thank-you!

 

[Laura]

Well, we knew we were onto something important but this just takes it to another level!

 

[Mikey]

If I understand correctly, summarized in one sentence (and please correct me if I am wrong): If you supply yourself with enough dietary fat, your body gets the signal to not go into immune attack against the food, but instead goes into full digestive and anti-inflammatory mode via the Vagus nerve. If you don't eat enough fat, it creates an immune-attack against the contents in your colon, and the colon itself, causing damage.

 

[Gaby]

We talked about it in the last podcast and the EE conference. It is indeed a fascinating concept

 

[mada85]

It also appears to me that a high fat diet is a low stress diet – another weapon in our armoury against stress. No wonder the PTB don't want people to eat a high fat diet! Keep them permanently stressed and tired and it's much easier to break their will.

 

[RedFox]

That's really interesting! Thanks Shane.

Just wanted to pick up another connection.....

Blocking nicotinic receptors also eliminated the antiinflammatory effects of dietary fat, thus solidifying the connection between fat-induced CCK and the cholinergic antiinflammatory pathway.

This tweaked some memories....anti smoking drugs!
_http://www.realage.com/the-you-docs/stop-smoking/prescription-antismoking-drugs-varenicline

Take the Kick out of Smoking with Varenicline (Chantix)
If nicotine didn't give you that familiar buzz, would you still smoke? Maybe not. Maybe the habit alone would keep you going. But makers of the newest non-nicotine prescription quit-smoking drug, varenicline (Chantix), are betting that taking the kick out of nicotine will make it easier to kiss goodbye all the reasons for lighting up.

Chantix diffuses the pleasure of nicotine by beating it to the punch -- that is, it blocks nicotine receptors in the brain so that smoking can't stimulate them in the way it used to. That makes having a cigarette much less pleasurable, and that, in turn, should make it easier to resist the desire to smoke.

However, we seldom prescribe Chantix. A key reason is that you can't combine it with nicotine replacement therapy -- a major help for most quitters. Also, we've had years and years of good experience with bupropion. Why argue with success?

That said, Chantix adds another weapon to the stop-smoking arsenal and is useful for people who don't do well on other drugs. If you are interested in it, call your healthcare provider well ahead of your quit date to talk it over, check for interactions, and get a prescription. Chantix is typically started 8 to 14 days in advance of your quit date, and then is typically taken for about 3 months, but an additional 3 months may be needed for some people to stay smoke-free.

A Cautions List
As with all drugs, Chantix has some possible drawbacks you need to be aware of:

Before taking Chantix, tell your healthcare provider if you have any history of psychiatric illness.
If you have feelings of anxiety, nervousness, tension, depression, unusual behavior, or thoughts about suicide while taking Chantix or after you stop taking it, call your healthcare provider. Immediately.
If you are breastfeeding, pregnant, or hope to become pregnant, you cannot take Chantix.
If you are taking Chantix, you cannot use nicotine replacement therapy.
If very vivid and unusual dreams disturb your sleep, talk with your doctor about lowering the dose.
Be alert to any change in your ability to drive or operate heavy machinery.
As your body adjusts to Chantix, you may have digestive side effects, such as constipation and gas. If you experience nausea or vomiting, try taking the drug after eating and with a full glass of water.
If you have kidney problems, a lower dose of Chantix may be safer for you.

So perhaps Chantix has the added effect of 'eliminated the antiinflammatory effects of dietary fat'?

 

[dantem]

There's such a consensus all around that animal fats are bad for your health and liver that I dare to call it conspiracy :D

Great find Shane!

 

[Laura]

There's such a consensus all around that animal fats are bad for your health and liver that I dare to call it conspiracy :D

Great find Shane!

And add to that conspiracy: anti-smoking! Smoking increases the number of acetylcholine receptors and enhances that anti-inflammatory response.

 

[Gawan]

Thanks for sharing Shane, very interesting.

And imagine if everybody is doing belly breathing (stimulating the vagus nerve, which further helps with digestion) and eating fat AND doing pipebreathing, sounds like a wondrous combination to me. :)

 

[shijing]

We talked about it in the last podcast and the EE conference. It is indeed a fascinating concept

Yikes -- sorry to miss that, Psyche and podcast presenters It was nice to think about this morning as I ate my bacon and fat-fried blinis, though :)

 

[dantem]

We talked about it in the last podcast and the EE conference. It is indeed a fascinating concept

Yikes -- sorry to miss that, Psyche and podcast presenters It was nice to think about this morning as I ate my bacon and fat-fried blinis, though :)

Yes, the big news out of that conference were that acetylcholine and animal fats reduce inflammation, and acetylcholine is also released by vagus nerve stimulation, and rolling your own helps too as Laura said!

What was hard to me at first was associating acetylcholine with a sort 'calming' effect, having thought of it as something that was activating the neurochemical signals and so that it was all about speed of connections... or so I had in mind before considering its anti-inflammatory properties. All those 'primary' neurochemicals such as dopamine, serotonin, acetylcholine and gaba have such a miriad of effects on our system and there's a lot to read before digesting :) all the ramifications.

 

[Stranger]

That's really a fascinating discovery!

Well, we knew we were onto something important but this just takes it to another level!

It is indeed illuminating to see the dots connected and begin to realize the bigger picture of this topic.

[quote author=MedicalNewsToday]Eating -- particularly eating fat-rich foods -- causes cells in the small intestine to produce a hormone called cholecystokinin, or CCK. CCK stimulates digestion and gut peristalsis (the motion that propels food along the digestive tract), and also triggers satiation -- the full feeling that prompts you to stop eating. [/quote]

During the last days I noticed, everytime I eat a lot of (gluten-free) bread I can't stop eating. Not only I can't stop eating this delicious self-made bread but also I feel hungry the whole day I eat a lot of bread and crave nearly nonstop for food. During this days I feel like a prisoner controlled by my desire to eat, unable to concentrate on other things than eating. Last summer I've eaten only fruits and vegetables for a few months - the same reaction occured. I was eating the whole day and couldn't even stop thinking of food.

When I cut out nearly all carbohydrates and especially bread and begin my day eating food rich in fat I don't feel hungry most of the time at all. I can begin the day with a piece of salami, an egg, a little bit faxseed oil and sometimes an avocado and the hunger is gone for 4 and more hours.

 

[Niall]

I can begin the day with a piece of salami, an egg, a little bit faxseed oil and sometimes an avocado and the hunger is gone for 4 and more hours.

Well Stranger, by the time you're ready to drench 3 buckwheat blinis in goose fat, grill 8 slices of bacon, fry 2 pork and black pepper patties, washed down with green tea and an extra-large RYO cigarette for breakfast, you won't know yourself :D I can basically go the whole day without thinking of food after that.

 

[herondancer]

Whoa Kniall, that describe mornings at my house perfectly! A grand start to the day, especially the blinis and bacon.