Brain function and thought patterns are intimately related to neurotransmitters, the chemical messengers that carry signals between neurons, or nerve cells, and other cells within the body. Neurotransmitters are essential for various physical and psychological functions including mood, anxiety, fear, joy, and happiness. They are also involved in regulating heart rate, sleep, and appetite.

There are two classifications of neurotransmitters that are named based on their effect on the brain: excitatory and inhibitory. Excitatory neurotransmitters have an excitatory effect on the neurons. They cause the neuron to fire an electrical signal called an “action potential” up the cell.  Some common excitatory neurotransmitters are epinephrine, norepinephrine, dopamine, acetylcholine, and serotonin.

Inhibitory neurotransmitters have an inhibitory effect on neurons, meaning they prevent the action potential from being fired. The most abundant inhibitory neurotransmitter is GABA.

How Are Neurotransmitters Produced in the Body?

Most neurotransmitter production begins with an amino acid from the diet or another chemical that’s already present in the body. Different amino acids are precursors for different neurotransmitters and the receptors to which they bind. Enzymes and various nutrients are required to convert these amino acids into neurotransmitters. B vitamins, vitamin D, minerals, and other compounds play a critical role in brain health to manufacture all neurotransmitters.

It’s worth mentioning that genetic variants can stop the production of these enzymes needed to make neurotransmitters.

We will discuss seven main neurotransmitters in this article, but keep in mind that there are more than 100 compounds that can act as neurotransmitters.

Acetylcholine

One of the primary roles of acetylcholine in the central nervous system is to promote cognition, memory, and arousal. It’s also involved in peripheral nervous system function and is used to activate muscles.

A deficiency in acetylcholine would look like a decrease in visual and verbal memory as well as frequent memory lapses. Individuals needing acetylcholine support might notice a decline in creativity or comprehension. Difficulty calculating numbers or recognizing objects and faces are also indicative of an acetylcholine issue.

Adequate dietary intake of healthy fats is important for acetylcholine production. Foods high in choline such as pasture-raised egg yolks, fatty grass-fed and pasture-raised meats and dairy, and nuts are helpful for acetylcholine production.

Catecholamines 

Epinephrine and norepinephrine are in a class of neurotransmitters called catecholamines. Technically, dopamine also falls into the catecholamine class, although dopamine will be discussed separately because of its different physiological effects. Additionally, take note that epinephrine and norepinephrine are also called adrenaline and noradrenaline.

Epinephrine and norepinephrine are involved with the body’s “fight-or-flight” response. When released into the bloodstream, they increase heart rate, pupil dilation, and shunt blood to muscles. In the brain, they stimulate receptors for mental speed, focus, and concentration. Likewise, a catecholamine deficiency might look like a reduction in mental alertness, speed, concentration, and cognition.

Dietary support for catecholamines could include foods high in tyrosine such as cheese, eggs, fish, nuts, seaweed, and turkey. Foods high in caffeine such as coffee, tea, and cacao also stimulate epinephrine and norepinephrine. That’s why caffeine can increase overall brain function.

Dopamine

Dopamine has various functions in the brain including motor coordination, mood, attention, learning, along with motivation and reward. It’s largely associated with the pleasure system of the brain.

Individuals with dopamine imbalances may experience feelings of worthlessness or hopelessness, or self-destructive thoughts. They often have an inability to handle stress and may feel angry while under stress. They sometimes desire isolation or have a lack of concern for loved ones.

Protein intake and assimilation along with proper blood sugar are important for dopamine production. Other key nutrients for dopamine production are oxygen, iron, and folate.

Serotonin

Also known as the “happiness neurotransmitter,” serotonin is found in both the central and peripheral nervous systems and is involved with mood, sleep, temperature regulation, and appetite. In fact, roughly 80 to 90 percent of the body’s serotonin production occurs in the gut.

Those with serotonin deficiencies often feel a loss of pleasure in their hobbies, interests, relationships, and favorite foods. They might have trouble falling asleep at night. Individuals with serotonin deficiencies sometimes have a strong dependency on others. Often, they can experience feelings of paranoia, rage, unprovoked anger, or sadness for no reason. Women with serotonin problems often suffer from premenstrual syndrome.

The body’s ability to create serotonin is a process that demands protein intake and absorption along with vitamins B3, B6, B9, B12, iron, and magnesium. Deficiencies in these nutrients can promote serotonin imbalances. Furthermore, blood sugar imbalances, tryptophan deficiencies, and gut problems can greatly affect serotonin levels.

GABA

Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain. Those with impaired GABA production usually experience feelings of dread, anxiety, or panic for no reason. They are easily overwhelmed, worry easily, and have a restless mind. Sometimes, it’s associated with disorganized attention, depression, and insomnia.

Foods that help with GABA include broccoli, buckwheat, chestnut, kale, oat, pea, potato, rice, shiitake, spinach, St John’s wort, sweet potato, tea, tomato, valerian, wheat, and wild celery. Additionally, compounds that can have a sedative effect on the brain and body include valerian root, ashwagandha, lemon balm, green tea, and lavender.

Leaky Gut, Leaky Brain, and Neurotransmitters

It’s also important to know that if you have a leaky gut, it can contribute to a compromised blood–brain barrier. Occludin and zonulin are two proteins that control both the gut barrier and the blood–brain barrier. When occludin and zonulin are elevated, it’s indicative of a leaky gut and a leaky brain. This means there is likely significant inflammation within the brain and neurotransmitter function can become faulty. If you suspect a problem with neurotransmitter signaling, restoring barrier function within the gut and brain are some of the first aspects that should be addressed.

It’s important to note that proper neurotransmitter production and brain function rely on many important nutrients. It is important to not only consume these valuable nutrients, but also be able to digest and absorb them. If you have digestive distress or suspect a leaky gut, it will be difficult for the body to utilize the nutrition in your food.

Next Steps

If you are concerned about any of these issues, a doctor such as a naturopath or integrative physician can do a thorough functional blood workup and gain important insight into gut integrity, blood sugar handling, and nutrient status. They can also order other functional lab testing to shed light on neurotransmitters and brain function.