Most practitioners are familiar with the concept that chronic inflammation,(or as we call it, the sustained inflammatory response) and chronic stress (or as we call it, the sustained sympathetic response) are deeply interconnected.
Remember, this is all adaptive. From an evolutionary point of view, when you are inflamed, you would have been fighting off an infection. And therefore, you would need to modify your behavior.
And your body does this by the immune system signaling to your nervous system.
However, fewer are aware that one of the body’s most important anti-inflammatory systems is directly dependent upon the neurotransmitter acetylcholine, and therefore heavily influenced by dietary choline intake (because choline goes on to produce, amongst other things, acetylcholine).
This system is known as the Cholinergic Anti Inflammatory Pathway (CAP).
At the centre of this pathway sits the vagus nerve, often referred to as the body’s “rest, digest and repair” nerve.
The vagus nerve forms a major component of the parasympathetic nervous system and acts as a brake against excessive sympathetic activation.
In simple terms, it helps calm inflammation, reduce stress signaling, improve recovery, and promote healing.
The key neurotransmitter used by the vagus nerve is acetylcholine.
Without adequate acetylcholine production, vagal signalling may be impaired, and the body can become increasingly trapped in sustained sympathetic dominance.
This is the classic “fight or flight” state many patients now appear to live in chronically.
Interestingly, many modern wellness strategies such as meditation, breath work, humming, gargling, cold exposure, vagus nerve stimulation devices (such as nurosym), yoga, and mindfulness practices are all fundamentally attempting to increase vagal tone and parasympathetic activity.
Yet all of these mechanisms still ultimately rely upon acetylcholine signalling working appropriately.
And this raises an important nutritional question:
What happens if dietary choline intake is low?
Note, in the UK we do not have a RDA/AI for choline and so it is a huge blind spot for most people, especially vegans who have no natural sources of significance.
In the USA the AI is 425 mg for females and 525 mg for males.
Most studies suggest less than 10% of population are hitting that target.
And it is easy to see why when you look at dietary sources, mg are per 100g of food.
Choline is an essential nutrient and the primary precursor required for acetylcholine production
The richest dietary sources of choline are egg yolks and liver. Outside of these foods, obtaining meaningful amounts becomes surprisingly difficult.
This becomes particularly relevant for individuals following low fat diets, plant based diets, calorie restricted diets, or simply consuming modern processed foods lacking nutrient density.
Many patients avoid eggs due to outdated cholesterol fears, while liver consumption has dramatically declined over the past several decades.
The result is that a significant proportion of the population may be functioning with chronically inadequate choline intake.
This matters because acetylcholine does far more than influence cognition and memory.
Research demonstrates that activation of the cholinergic anti inflammatory pathway can directly suppress inflammatory cytokine production, including TNF alpha, IL 1 beta, and IL 6.
The vagus nerve essentially acts as a neural anti inflammatory circuit, communicating with the immune system and helping regulate excessive inflammatory responses.
‘autonomic regulation of local and systemic inflammation through the ‘cholinergic anti-inflammatory pathway’, a mechanism consisting of the vagus nerve and its major neurotransmitter, acetylcholine’
When vagal tone is low, sympathetic drive often remains elevated. This can contribute to increased cortisol output, poorer sleep quality, altered heart rate variability, heightened pain sensitivity, digestive dysfunction, impaired recovery, and sustained low grade inflammatory response.
Many practitioners now recognise patterns of “wired but tired” physiology in patients. They are exhausted, inflamed, anxious, hypervigilant, sleep deprived, and unable to fully switch off.
While there are clearly multiple contributors to this state, insufficient cholinergic signalling may represent one overlooked component.
This may also help explain why some individuals feel profoundly calmer or more resilient when implementing interventions that improve parasympathetic tone.
Meditation, slow nasal breathing, singing, prayer, social connection, and vagal stimulation techniques may all partly work by improving acetylcholine mediated vagal activity.
However, from a biochemical perspective, one could argue that supporting acetylcholine synthesis nutritionally should also form part of the conversation.
This is where ensuring adequate choline intake becomes highly relevant.
We always want to encourage eggs (if tolerated), and ideally liver, though the latter is a hard sell !
But for some, the IN Health Choline provides a convenient way to support dietary choline intake in individuals who may not regularly consume eggs or organ meats.
Two capsules gives 600 mg of our patented and scientifically tested (including in pregnant women) VITACHOLINE.
Supporting acetylcholine production may help support healthy nervous system signalling, cognitive function, liver function (may help resolve fatty liver), methylation pathways, and potentially parasympathetic balance.
Importantly, choline also intersects with methylation pathways alongside nutrients such as folate, B12, and betaine.
The body can partially compensate for low choline intake by increasing demand on methylation pathways, meaning chronic insufficiency may have wider systemic implications beyond neurotransmitter production alone.
Perhaps one of the most important clinical concepts is this:
The nervous system and immune system are not separate systems.
The vagus nerve is one of the major communication highways between the brain and the immune system.
Acetylcholine acts as one of the key messengers controlling this dialogue.
If modern lifestyles are increasing sympathetic activation through stress, poor sleep, excessive screen exposure, social isolation, under recovery, ultra processed diets, and sustained inflammation, then supporting the body’s primary parasympathetic neurotransmitter system may become increasingly important.
In many ways, the cholinergic anti inflammatory pathway reminds us that inflammation is not purely biochemical.
It is neurological too.