What Foods Are Central Nervous System Stimulants?
There are several foods that contain substances that stimulate the body’s central nervous system (CNS). These foods include:
- Coffee
- Chocolate
- Tea
- Alcohol
- Tobacco
However, before discussing foods that are rich in stimulants of the central nervous system (CNS), it is important to introduce the CNS and the different classes of stimulants.
1- What Is the Central Nervous System?
The nervous system is divided into the central nervous system (CNS) and the peripheral nervous system (PNS).
The central nervous system is made of the brain and the spinal cord that are protected within the skull and the spine (vertebral column).
Nerves that leave or enter the central nervous system (CNS) are known as the peripheral nervous system and are divided into sensory nerves and motor nerves.
Sensory nerves are the nerves that transmit information from the body to the brain, while motor nerves transmit information from the brain to the body.
2- What do Stimulants Do to the Central Nervous system?
Stimulants induce the activity of the central nervous system through the following mechanisms:
- Increase the release of neurotransmitters
Depending on the type of neurotransmitter, some of them reduce nerve impulses such as GABA, while other transmitters promote nerve impulses such as glutamate.
- Stimulate post-synaptic receptors
When neurotransmitters are released in the synapses by a neuron, they go and bind to receptors on the receiving neuron or organ. It is like crossing from one side of a river to the other side. These receptors are called post-synaptic receptors.
- Block the reuptake of neurotransmitters
After a neurotransmitter has completed its function, it is reabsorbed by a transporter that is found on the cell membrane of a neuron.
This reuptake of neurotransmitters is a type of recycling that also allows the control of the duration of the activity of the neurotransmitter.
An excess of neurotransmitter activity can result in excitotoxicity which is associated with excessive activation of the neurotransmitter that can cause damage or death of nerve cells.
Damages and death of the nerve cells that are due to excitotoxicity can result in diseases such as neurodegenerative diseases (Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis), traumatic brain injury, and stroke.
Neurotransmitters are messengers that transmit specific chemical instructions from a neuron to another neuron and from neurons to tissues and organs.
Here are some of the neurotransmitters found in the central nervous system:
As neurotransmitters are chemical messengers, they hold instructions such as excitatory (Doing) or inhibitory (Stop doing) information that is communicated and conveyed between neurons until they reach the target tissue or organ responsible for the execution of a specific action such as thinking, learning, emotions, memory, and movement.
3- CNS Stimulants Classification
- Analeptic stimulants
Analeptic stimulants are substances that stimulate respiration. They are mostly used for respiratory depression during coma, due to drug overdose or anesthesia [1].
Analeptic stimulants include plant alkaloids such as strychnine and synthetic compounds such as doxapram and pentylenetetrazol.
- Psychomotor Stimulants
Psychomotor stimulants are substances that stimulate arousal, alertness, and motor activity. They are clinically used for the treatment of attention-deficit or hyperactivity disorder.
This type of stimulant includes compounds such as cocaine and amphetamines.
- Methylxanthines
Methylxanthines are substances that are naturally present in certain plants and that derive from the purine base xanthine.
They are used in the treatment of lung conditions such as asthma and COPD (Chronic obstructive pulmonary disease) but are also used as general stimulants [2].
This type of stimulant includes caffeine, theophylline, and Theobromine.
4- What Foods Are Stimulants
- Coffee
Coffee is rich in the methylxanthine stimulant caffeine which has psychoactive effects on the central nervous system resulting in changes in perception, cognition, mood, behavior, and consciousness.
The psychoactive effect of caffeine is associated with its inhibition of the neurotransmitter adenosine which is a depressant that favors sleep and blocks arousal [3].
- Tobacco
Tobacco is rich in nicotine that stimulates the central nervous system by inducing the release of neurotransmitters, including acetylcholine, dopamine, serotonin, b-endorphin, and norepinephrine.
In addition to its effect on mood, nicotine intake also results in vasoconstriction (narrowing of vessels), tachycardia, and hypertension [4].
Medically, nicotine (not tobacco) is used to reduce aggression in individuals with autism spectrum disorder [5].
Nicotine is found at a higher concentration in tobacco products; however, it is also found at very low concentrations in potatoes, tomatoes, and eggplants.
- Chocolate
Chocolate contains the methylxanthine stimulant theobromine which inhibits the function of the neurotransmitter adenosine, a depressant that favors sleep and blocks arousal [6].
The inhibition of the neurotransmitter adenosine is like the caffeine one but at a lower level.
Theobromine is also a vasodilator (widening of vessels), a diuretic, and a heart stimulator. Medically, it is used as a bronchodilator and a vasodilator.
- Tea
Tea contains caffeine but also low levels of theophylline and theobromine. Theophylline is also a methylxanthine stimulant that blocks the activity of the neurotransmitter adenosine [7].
Theophylline is a vasodilator, a smooth muscle, and cardiac muscles stimulant, and a diuretic.
It also increases gastric secretion and plays a role in anti-inflammation.
Medically, theophylline is used for the treatment of asthma.
- Alcohol
Alcohol is also known as ethanol. Alcohol is a stimulator of the central nervous system through the induction of the release of the neurotransmitter, dopamine, which results in a feeling of pleasure.
However, this stimulant effect is soon replaced by an anti-depressant effect [8].
Conclusion
Coffee, tea, chocolate, alcohol, and tobacco are consumed by many people in the world. While health risks associated with chocolate, tea, and coffee are very low, the consumption of alcohol and tobacco have a higher health risk.
Although the consumption of caffeine is associated with a dependency associated with its relatively strong methylxanthine stimulant effect, nicotine and alcohol consumption have much higher dependencies that can be extremely difficult to cure.
In addition, tobacco smoking is a well-known risk factor for cancer, while alcoholism can lead to mental health issues such as depressed mood and an increased risk of suicide. Other effects of alcoholism are associated with an increased risk of diseases such as liver cirrhosis, heart disease, epilepsy, and alcoholic dementia.
