10 Causes of Restless Leg Syndrome (RLS)
What is Restless Leg Syndrome?
Restless leg syndrome involves an irresistible urge to move your legs to relieve unpleasant sensations often described a crawling sensation, "itchy nerves" or "itchy bones". While restless leg symptoms tend to be worse at night we can actually experience restless legs at any time of day. When restless legs stop us from getting enough sleep this can trigger a vicious cycle where lack of sleep exacerbates our restless leg symptoms and restless legs exacerbates our lack of sleep.
What Causes the Condition?
When it comes to restless leg syndrome there are many possible triggers and underlying conditions to investigate and each person is going to be different. This is why I recommend getting a full health assessment with a qualified health practitioner to find out what the key factors are for you and put you onto a personalised treatment plan. However to get you started here are some common factors to consider.
1. Dopamine Imbalances
Dopamine is an important brain chemical that regulates functions like mental stimulation, alertness, mood, stress and movement. Research into restless leg syndrome has found a link between symptoms and dopamine dysfunction, and researchers believe that low dopamine activity is a cause of symptoms. This theory is used to explain why restless leg symptoms are more common at night when dopamine levels drop. It is also supported by the finding that medications which increase dopamine levels seem to provide short-term relief for restless leg symptoms. However in the long-term using these dopamine boosting medications has also lead to symptoms getting worse. Why could this be?
Fewer Dopamine receptors not lower Dopamine levels
While "low dopamine activity" may trigger restless legs, it has been found that fewer dopamine receptors might be the culprit. Our brain is very good at keeping us in balance and when it is constantly flooded with a particular chemical it can adapt by reducing the number of available receptors that chemical can act on. This is why party drugs like MDMA (ecstasy) that flood the brain with serotonin for example, can have a weaker effect over time and lead to long-term brain changes that impact anxiety, mood and sleep. In the case of restless leg syndrome a similar process could be involved where higher dopamine levels overtime lead to reduced receptor sites, and paradoxically low dopamine symptoms.
2. Iron Deficiency or Excess
Restless legs is a common complaint for those who also have iron deficiency anemia and approximately 24% will experience restless legs. Addressing iron deficiency such as with iron supplements has also been found to relieve symptoms. Interestingly, it appears that low "brain levels" of iron in particular, may play a key role in restless leg syndrome. Iron is required for the synthesis of dopamine which regulates movement, as well as hormones like melatonin and serotonin which support sleep and calm. When brain levels of iron are reduced, this may affect the synthesis of these chemicals. It has also been linked to reduced dopamine receptors.
In addition to iron deficiency, individuals with elevated iron levels such as those with the genetic condition, hemochromatosis, have also been found to suffer from restless leg syndrome. While people with hemochromatosis may have high levels of iron in their blood, it has been found that these individuals may have reduced brain levels of iron. This may be a protective mechanism since iron can trigger inflammation and cause organ damage when it builds up in certain tissues.
3. Other Nutrient Deficiencies
Deficiencies in B vitamins such as folate, vitamin B12, vitamin B6 and other B vitamins could play a role in exacerbating restless leg symptoms. B vitamins are crucial for sustaining healthy levels of brain chemicals such as dopamine, helping us to make these chemicals as well as remove them from the body so that they don't reach excess. Magnesium is also an important mineral needed to keep stress chemicals in balance, to relax nerves and muscles and support sleep. Deficiencies in vitamin D are common in those with restless legs and supplementing vitamin D has been found to be helpful in some cases. Low vitamin D levels along with elevated iron levels can be another sign of underlying inflammation and this is where addressing inflammation is key.
4. Medication Side Effects
Certain medications can exacerbate restless leg symptoms. This includes beta-blockers, anti-depressant medications which increase serotonin, some types of anti-histamine medications, anti-psychotic medications, and anti-nausea drugs which affect dopamine activity. There are often alternatives available for these medications which do not cause the same side effects.
5. Glutamate-GABA imbalances
Glutamate is the main stimulating chemical in our brain, while GABA is our main calming brain chemical. Glutamate and GABA can be converted interchangeably into one another, and are often referred to as "the accelerator" and "the brake" because of how they counterbalance each other.
At the right level glutamate keeps us focused and alert, but in excess we can experience overstimulation and anxiety. Research has also found higher glutamate levels in those with restless leg syndrome. Medications that increase GABA activity on the other hand have been found to reduce restless leg symptoms. When it comes to relieving restless leg syndrome balancing glutamate and GABA activity may be an important factor and it is possible to do this naturally by supplying the right nutrient co-factors.
6. Gut Conditions
Gut conditions that lead to inflammation in the gut wall have been associated with restless leg symptoms. When the gut is inflammed a hormone called hepcidin is released in larger amounts. This hormone changes how the body stores iron and can lead to lower levels of iron in the brain, which has been linked with restless leg symptoms. Some common gut conditions which can involve inflammation include small intestinal bacterial overgrowth, gut dysbiosis and inflammatory bowel disease. Gut conditions that cause malabsorption of nutrients like iron, such as Celiac disease can also contribute to iron deficiency.
7. Food Allergies and Intolerances
Food intolerances and food allergies can exacerbate gut problems and lead to malabsorption of iron, increased inflammation and lower levels of iron in the brain. Gluten intolerance can also lead to autoimmune changes that increase glutamate activity and reduce GABA levels. Certain foods may trigger restless leg symptoms for unknown reasons.
8. Food Chemical Sensitivities
Some people are sensitive to artificial chemicals added to foods, as well as food chemicals that exist naturally in foods, such as salicylates, amines and glutamates. People who are food chemical sensitive can experience a variety of different symptoms ranging from skin rashes to headaches and restless legs. Monosodium glutamate (MSG) is a good example of a common additive found in processed foods which can trigger restless leg symptoms in some people. When restless leg symptoms are triggered by food chemical sensitivity following a low food chemical diet can provide effective relief.
9. Estrogen Dominance
Research has found that restless legs symptoms are more common in women. Symptoms also seem to be exacerbated by hormonal changes, with the problem being more common in the 3rd trimester of pregnancy and in women going through menopause. One theory is that estrogen dominance, which is defined as higher levels of estrogen relative to progesterone, might play a role in triggering symptoms. This means that hormone medications such as the pill, hormonal fluctuations across the menstrual cycle, across pregnancy and menopause, as well as major hormonal imbalances seen with conditions like endometriosis, may exacerbate symptoms of restless legs.
10. Stress, Inflammation and Histamine
Least surprising of all, stress can play a big role in triggering restless leg syndrome. Mental and emotional stress can exacerbate inflammation, affect dopamine activity, and increase histamine levels, another chemical thought to play a role in restless leg syndrome. Inflammation leads to reduced vitamin D levels as well as reduced brain levels of iron which have been linked to restless leg symptoms. Excess histamine can drive inflammation, and is found to influence dopamine activity in the brain. Histamine excess is linked to a number of other underlying conditions, including gut conditions, hormonal imbalances, allergies, food sensitivities and mast cell activation disorders.
What Can You do to Relieve RLS?
In addition to treating the underlying drivers of restless leg symptoms there are some simple things we can do to bring relief. Avoiding stimulants such as caffeinated foods and drinks, coffee (even decaf!), cocoa and nicotine may help to reduce symptoms. While alcohol may relieve symptoms initially, it can affect dopamine levels and exacerbate glutamate-GABA imbalances in the long-term and make symptoms worse. Supplementing nutrients such as magnesium, zinc and vitamin B6 before bed can help to reduce restlessness and assist with sleep. Regular yoga and meditation have also been found to significantly reduce symptoms of restless leg syndrome.