Endocannabinoid Tone and Fibromyalgia

Fibromyalgia is a chronic condition that causes pain throughout the body.

It was initially considered to be an inflammatory condition similar to arthritis, but it's now understood to be linked to the neurological systems that experience and process pain signals.

There is no cure, the best that people with fibromyalgia can hope for is a way to manage the condition and reduce the symptoms.

According to Bupa, one in twenty people in the UK suffers from fibromyalgia.

It can start at any age, although it's most often first noticed between the ages of 20 and 60. It's also more common in women than men.

The most common symptoms of fibromyalgia are:

• Chronic pain – this can be experienced across the whole body or in several specific areas.
• Fatigue or an overwhelming feeling of being tired
• Insomnia and poor sleep quality
• Stiffness in the muscles and joints
• Tingling sensations in the arms and legs.
• Lack of concentration
• Feelings of overwhelming tiredness throughout the day

Although there is still no concrete understanding of exactly what causes fibromyalgia, there are several factors that the NHS have identified as being linked to it:

Abnormal pain messages – One theory is that people with fibromyalgia have experienced minute but crucial changes to their central nervous system.

Chemical imbalances - People with fibromyalgia have abnormally low levels of serotonin, noradrenaline and dopamine.

Sleep problems – Some doctors suggest that poor sleep may not just be a symptom of fibromyalgia but may be one of the causes.

Genetics – Some genes may make some people more likely to develop fibromyalgia. This may be why some people develop it after certain triggers and others don't.

Triggers – For many people with fibromyalgia, it appears to be triggered by a stressful event such as injury, infection, giving birth or emotional trauma. 

Associated conditions – There are several conditions with similar conditions that can appear to be linked to fibromyalgia in some people. These include osteoarthritis, lupus, rheumatoid arthritis, ankylosing spondylitis and temporomandibular disorder.

Currently, treatment for fibromyalgia includes:

• pain medication
• antidepressants
• insomnia medication
• muscle relaxants
• cognitive behavioural therapy
• relaxation techniques
• tailored exercise programs, 
• acupuncture 
• massage

There are various treatment options because fibromyalgia has many different symptoms and can present differently from person to person.

Also, as the condition develops, the symptoms may change, or treatments that provided relief previously may appear to stop working.

What is CBD?

CBD is one of over 100 cannabinoids found in plants of the cannabis genus.

It's non-intoxicating and is extracted from hemp to be used as a food supplement.

The CBD extract is combined with other beneficial ingredients to make a range of products, including oils, capsules, e-liquids or gummies.

When you consume CBD, it enters your cells and tissues and interacts with a broad range of chemical messenger molecules, enzymes and receptors.

These interactions support your body's ability to restore your body systems to a state of healthy balance.

Learn more about CBD with our guide: CBD 101 – Everything you need to know

CBD and Your Endocannabinoid Tone

CBD works in your body in many different ways, but one of the most vital interactions is how it stimulates the endocannabinoid system (ECS) and raises your endocannabinoid tone:

What is the endocannabinoid system?

The endocannabinoid system is a collection of signal molecules (endocannabinoids), receptors and enzymes. It's active throughout the body, particularly in the central and peripheral nervous systems.

When the ECS is activated, it makes tiny chemical adjustments that enhance the signalling capacity of cells within your body.

This allows your various body systems to communicate effectively and quickly restore a healthy balance following damage or illness.

What is your endocannabinoid tone?

Endocannabinoid tone refers to the level of potential endocannabinoid activity in your body and the ability of your endocannabinoid system to respond to any problems.

This can be affected by a range of factors, including genetics, diet, stress and disease.

If your endocannabinoid tone is low, your endocannabinoid system is unlikely to be able to restore your body systems to a state of healthy balance.

As a result, you may feel unwell or experience symptoms related to anxiety. 

Regular consumption of CBD can stimulate the action of your endocannabinoid system (ECS) and raise your tone. 

To learn more about how CBD raises your endocannabinoid tone, you can read our article: Endocannabinoid Tone and CBD

Key terms:

CB1 and CB2 – These are the most common endocannabinoid receptors.

• CB1 is found in the central nervous system.
• CB2 is present in the central nervous system, the peripheral nervous systems and in immune cells throughout the body

Anandamide (AEA) and 2-Arachidonoylglycerol (2-AG) – These are endocannabinoid signalling molecules present in humans and animals. They can interact with a range of chemical receptors, including CB1 and CB2.

Fibromyalgia and your Endocannabinoid Tone

Fibromyalgia has no obvious cause, but some doctors and scientists believe that it may be the result of low endocannabinoid tone.

For the last twenty years, they have been developing and testing the theory of clinical endocannabinoid deficiency.

This theory suggests that many previously unexplained conditions, including fibromyalgia, are caused by extremely low levels of endocannabinoid activity. 

A 2016 study re-evaluated the theory and found that current research demonstrates links between low endocannabinoid tone and migraines, fibromyalgia and irritable bowel syndrome.

University of Vermont scientist, John McPartland presented evidence fibromyalgia is related to endocannabinoid deficiency.

He also suggested that enhancing the function of the endocannabinoid system could offer an approach towards treating fibromyalgia. 

The link between the endocannabinoid system and fibromyalgia is particularly clear in the mechanisms involved with pain:

Low endocannabinoid tone results in sensitised pain receptors

When tissue is damaged, chemicals are released to trigger the pain receptors (nociceptors).

They also release substances called sensitizers. These include prostaglandins, leukotrienes, noradrenaline and calcitonin.

The sensitisers lower the pain threshold of the pain receptor, allowing it to be triggered by a lower level of pain stimulus.

This process is called 'peripheral sensitisation' and results in certain areas of the body feeling pain from small actions that would normally be painless.

Normally, sensitisation causes an automatic balancing response from the endocannabinoid system.

When CB1 receptors are activated, they reduce the sensitisation making it less likely the pain receptor will fire.

Also, it reduces the release of the sensitisers in the surrounding tissue.

In someone with low endocannabinoid tone, the pain receptors remain sensitised leading to fibromyalgia and other chronic pain conditions.

Low endocannabinoid tone and the dorsal horn 

The dorsal horn is a subsection of the grey matter found in the spinal cord.

It's a collection of neurons that forms a gateway between the messages coming from your body and your central nervous system.

If your pain receptors have been sensitised and are producing continuous signals, it can initiate the release of glutamate in the dorsal horn.

This sets off a chain reaction that leads to the sensitisation of the dorsal horn itself.

This means that when pain signals pass through the dorsal horn it may enhance them or even initiate a new signal from other non-pain stimuli.

In this sensitised state, spinal neurons may even fire spontaneously without any pain stimulus.

In this situation, if the endocannabinoid tone is medium or high, CB1 receptors will be activated.

This closes the channels that deliver the glutamate.

For someone with a low endocannabinoid tone, it’s likely that this chain of events could lead to fibromyalgia.

Low endocannabinoid tone and dopamine signalling 

Dopamine is a neurotransmitter that assists communication between different areas of the brain.

As well as working within the brain it's also involved in a descending pain pathway.

This is a series of signals that travels down from the brain to the rest of the body to assist with the control of pain signals fired from the pain receptors.

A 2017 study states that the dopamine system in the brain is intertwined with and dependent on the endocannabinoid system.

If the receptors and dorsal horn have been sensitised and are firing in an unregulated way, CB1 and CB2 receptors are activated.

This activation produces a moderating effect on the neurons responsible for releasing dopamine.

Consequently, dopamine release is brought back under control and is once again able to send the necessary signals and support the pain pathway.

When enough dopamine is released it's able to work in synergy with the endocannabinoid system to regulate pain signals and reduce the effects of the sensitisation experienced by people with fibromyalgia.

As well as reducing unregulated pain signalling, proper dopamine release can also reduce anxiety, improve focus, decrease fatigue and regulate sleep.