What is Acetylcholine?
Acetylcholine is a neurotransmitter — a chemical messenger that allows your nerves to communicate with each other and with our organs. It is important to identify the symptoms of low acetylcholine because acetylcholine is our most common neurotransmitter and is used throughout our nervous system.
Central Nervous System
In the brain (the central nervous system) acetylcholine allows your neurons to communicate making it possible for you to think clearly and to form short-term memories. Without optimal acetylcholine levels in the brain, cognition becomes sluggish causing “brain fog”.
Peripheral Nervous System
Your muscles use acetylcholine, too (the peripheral nervous system). Low acetylcholine levels can result in weakness and fatigue.
Autonomic Nervous System
Acetylcholine is also required by the autonomic nervous system — the system of the body that you don’t need to think about. The functions of the autonomic nervous system include heart rate, blood pressure, breathing, blinking, digestion, and many others! The autonomic nervous system controls your vagus nerve which is the anti-inflammatory system of the body. When it is not performing optimally, chronic inflammation can occur. Your vagus nerve (via the messenger acetylcholine) controls every aspect of digestion including movement of food through the upper GI tract beginning with swallowing, normal stomach acid production, the opening of the pyloric valve at the base of the stomach allowing food to pass into the intestines, movement of stool through the intestines, gallbladder functioning to release bile for digestion of fats, pancreatic functioning to release digestive enzymes, and movement of the stool (“peristalsis”) to trigger a bowel movement.
Parasympathetic Nervous System
The parasympathetic nervous system — the “rest and digest” system of the body — depends upon acetylcholine as well. Acetylcholine is the chemical messenger that allows your body to calm down after a surge of adrenaline occurs — only then can you get in a relaxed state and begin digestion.
What Causes Low Acetylcholine?
Some of the most common causes of low acetylcholine are genetic errors, chronic illness, chronic inflammation, some medications, and aging. Diagnosing low acetylcholine can be difficult since there is no blood test available; therefore low acetylcholine is a clinical diagnosis based on symptoms. Low acetylcholine levels can also occur in anticholinergic poisoning.
Symptoms of Low Acetylcholine In Anticholinergic Syndrome
When patients ingest massive doses of anticholinergic medications (such as accidental poisoning with atropine), anticholinergic syndrome occurs. The symptoms of anticholinergic syndrome are recognized based on presentation (clinical signs and symptoms). The symptoms of low acetylcholine are easy to miss because they can mimic many other conditions.
Doctors have a mnemonic to remember the presentation of low acetylcholine levels in anticholinergic syndrome: “Blind as a bat, dry as a bone, red as a beet, mad as a hatter, can’t see, can’t pee, can’t poop”. What do these symptoms mean and what other symptoms occur in anticholinergic poisoning?
1. “Brain Fog”, Poor Short-Term Memory:
Acetylcholine is the neurotransmitter needed by the neurons of the brain to communicate with each other. Low acetylcholine causes difficulties with cognition, “brain fog”, and mental fatigue.
2. Fatigue, Especially Fatigue That Worsens With Exertion:
Acetylcholine is required by the peripheral nervous system allowing muscles to work. Insufficient acetylcholine levels result in muscle weakness that worsens with exercise or exertion. The muscles may work for a while, then exhaust their supply of acetylcholine, leading to extreme fatigue.
3. Constipation / Gastroparesis (“can’t poop”):
The vagus nerve uses acetylcholine to assist every aspect of digestion including peristalsis (movement of food or stool through the digestive tract). Stomach acid production, the opening of the pyloric sphincter at the bottom of the stomach, gallbladder function, some pancreatic function, and opening of the Sphincter of Oddi (which allows bile and pancreatic enzymes to pass into the intestines). Therefore, low acetylcholine levels are especially detrimental to the digestive tract.
Because the vagus nerve is such an important part of the digestive tract low acetylcholine levels can be especially detrimental. Chronic constipation and/or gastroparesis. are very common symptoms of low acetylcholine.
Poor digestion and poor absorption of critical nutrients are also common symptoms of low acetylcholine potentially leading to malnutrition.
4. Dry Eyes (“dry as a bone”):
Normal tear production is a process of our autonomic nervous system. Acetylcholine is required by the lacrimal gland to produce tears. Acetylcholine is also used by the nerves to tell our bodies when to produce tears. When levels of acetylcholine are low, dry, painful eyes can result. Dry eyes due to insufficient acetylcholine are resistant to conventional dry eye treatment unless acetylcholine levels are restored.
5. Orthostatic Hypotension:
Suboptimal acetylcholine levels can cause low blood pressure when standing, causing dizziness and weakness.
6. Flushing (“red as a beet”):
Patients with low acetylcholine often experience episodes of flushing (redness) on the face. The neck and other parts of the body may also appear flushed. It is common for flushing to be misdiagnosed as rosacea or mast cell activation.
7. Emotional Instability (“mad as a hatter”):
People with low acetylcholine levels often suffer from the inability to cope with their emotions. Their emotional state can be unpredictable.
8. Chronic Inflammation:
Acetylcholine is needed by the vagus nerve (the anti-inflammatory pathway of the body). Low levels of acetylcholine contribute to consistently high inflammation which can cause pain, atherosclerosis, fatigue, hypercoagulation (easy blood clotting), and premature aging. Chronic inflammation is an often overlooked symptom of low acetylcholine which results in accelerated aging.
9. Fast Heart Rate (Tachycardia):
The parasympathetic nervous system is the body’s “rest and digest” system. When levels of acetylcholine are insufficient, the vagus nerve no longer slows down the heart. If the heart can not be properly slowed the body cannot rest. The vagus nerve relies upon acetylcholine to stimulate the sinoatrial node of the heart to normalize the heart rate.
10. Large Pupils (“blind as a bat”):
Pupil size is a function of the balance between the sympathetic nervous system (large pupils) and parasympathetic nervous system (small pupils). Suboptimal acetylcholine levels upset this balance. When the balance is upset, the sympathetic nervous system overrides the parasympathetic nervous system, resulting in large pupils. Large pupils often cause light sensitivity and difficulty focusing.
If you have some of these symptoms and yet you have not been poisoned, you could be dealing with less than optimal levels of acetylcholine, perhaps due to genetics, aging, or inflammation.
Can You Support Proper Acetylcholine Levels?
Can something be done to optimize low acetylcholine levels? Can we provide what our bodies need in a way that also stimulates the vagus nerve?
Yes, we can.
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