Magnesium for Nerve Pain

Overview

Magnesium (Mg) is an essential dietary mineral needed for many functions of the body. It helps maintain normal heart rhythm, blood pressure and insulin levels, and is vital for DNA repair and cell renewal. It is also important for the functioning of the nervous system, supporting how nerve cells communicate with each other to create sensation and connect with muscles to allow proper movement.  According to one study’s estimates, between one-fifth and a quarter of all people suffer long-term nerve-related pain due to a variety of reasons.  A magnesium deficiency can create and exacerbate nerve-related problems including some painful medical conditions.¹

Role of magnesium for nerve pain

Neuropathic pain results from a dysfunction of the pathways of the nervous system.²  Pain can originate from damaged nerves in the central nervous system due to, for example, a spinal cord injury, or in the peripheral nervous system where damaged nerves are found in the limbs - also known as peripheral neuropathy.^3,4 

Peripheral neuropathy can also be a symptom of some medical conditions like diabetes. Diabetic neuropathy commonly affects the hands and feet where patients experience loss of feeling, pins & needles and an enhanced feeling of pain in these areas.³  

Peripheral neuropathy and neuropathic pain can also manifest as a result of some medical treatments, for example:

• Chemotherapy - where inadvertent damage to healthy nerve cells by radiation causes the condition called chemotherapy-induced peripheral neuropathy³ 
• Surgery - where mechanical interventions can result in neuropathic pain during a patient’s healing and recovery period³ 

Neuropathic pain is usually treated with strong prescription painkillers, such as opioids, or with alternative therapies like acupuncture.²

However, magnesium supplements offer another alternative treatment to nerve pain as they work at the site of nerve inflammation as a nerve block. It specifically targets and blocks NMDA receptors - a common pain pathway. This is the same pathway used by the anaesthetic drug ketamine, to impede the sensation of pain during invasive procedures.  Nerve pain is caused and amplified at the site of injured nerves when there are too many neurotransmitter molecules (glutamate) and calcium ions flooding the NMDA receptors. Magnesium blocks this effect and this results in the numbing of the affected nerve tissue and reduction in nerve pain.³

Magnesium (Mg) supplementation also has an anti-inflammatory effect, providing pain relief and slowed progression in some nerve conditions. For example:

• Chronic lower back pain - patients from one trial reported feeling less pain in the affected area after a treatment of intravenous Mg followed by a 6 month course of oral Mg¹
• Fibromyalgia - patients with fibromyalgia from another trial reported feeling less pain after taking an Mg supplement in combination with a regularly prescribed fibromyalgia medication (amitriptyline)¹
• Multiple sclerosis (MS) - patients with MS monitored over 1-2 years while taking an Mg supplement (plus calcium and vitamin D) showed signs of slowed progression/worsening of the disease⁵
• Sciatica - Mg supplementation can reduce further damage and inflammation seen in the condition and aid in the recovery of the sciatic nerve⁶

Magnesium also supports the cells involved in nerve regeneration by repairing nerve endings and their vital protective coating (myelin sheath). This ensures nerves which have been injured by an accident, procedure, or condition are less affected by long-term damage.⁷

Effects of magnesium deficiency on the nerve

Although health experts say magnesium deficiencies may be common in the population, they are difficult to notice as people may present as asymptomatic or with vague symptoms characteristic of other deficiencies and conditions like tiredness and sickness.  However, a magnesium deficiency can be easily diagnosed from a blood sample. You may also be more prone to having low magnesium if you have trouble absorbing and utilising nutrients from food (for example,  in Crohn’s disease, coeliac disease, type 2 diabetes and alcoholism).⁸

Low magnesium can affect the nervous system in several ways. As nerves control the musculoskeletal system, symptoms such as muscle weakness, cramping, pain and rigidness have been observed. Magnesium deficiency also causes nerve sensations characteristic of peripheral neuropathy. In severe cases, it can lead to an irregular heartbeat and seizures due to improper nerve signalling to the heart and skeletal muscles.⁸

There is also some evidence that links depleted magnesium levels to progressive diseases of the nervous system, like Alzheimer’s and Parkinson's disease, due to unregulated inflammation of nerves in its absence.⁷

How much magnesium to take for nerve pain?

NHS guidelines say that adult men and women require 300mg and 270mg of magnesium per day, respectively. They also warn against ingesting more than 400mg of magnesium daily to avoid any adverse gastrointestinal effects.⁹

One dose of supplement per day will range from 250-500mg of magnesium. However, you should follow regional guidelines, the advice of your doctor, and the packet information before you take anything. Talking to a doctor is especially important for people with kidney problems as supplementation can lead to a toxic build-up of magnesium levels.¹⁰

Magnesium (Mg) supplements are found in a variety of forms including:

• Magnesium glycinate - a common oral supplement used to treat Mg deficiency in the form of a salt¹¹
• Magnesium sulphate -  used to treat Mg deficiency and pregnancy complications (preeclampsia and eclampsia)¹²
• Magnesium citrate - used to treat Mg deficiency but is also contained in some laxative medications, and in strong concentrations can be used for pre-colonoscopy bowel emptying¹³
• Magnesium oxide - a cheaper Mg supplement option but often has a poor absorption rate in the gut¹⁴
• Magnesium chloride - known as a particularly absorbable form of Mg supplement either by ingestion or application to the skin (magnesium oil and bath salts)¹⁵
• Magnesium taurate and magnesium malate - also highly absorbable forms of Mg supplement but with higher retail prices¹⁴

Intravenous magnesium (usually magnesium sulphate) is also a treatment option in monitored, clinical settings for those in need of neuropathic pain relief, and in patients undergoing and recovering from surgery.^16,17

Magnesium can also be easily acquired from a wide range of foodstuffs with relatively high Mg content, such as:

• Seeds and nuts (pumpkin seeds, almonds, peanuts and cashews)
• Beans (black, kidney and edamame) 
• Wholemeal bread
• Wheat and fortified cereals
• Brown rice
• Potatoes 
• Avocado
• Spinach
• Banana 
• Soy milk 
• Yogurt (plain)
• Dark chocolate¹⁸

Summary

Nerve or neuropathic pain can be difficult to manage whatever the cause. So, if you’ve been stuck in a rut with other medications or have exhausted other pain relief options, adding magnesium to your diet may be a good choice for you. This can be done through purposeful food choices or by trying a magnesium supplement. You should also consider how magnesium could benefit or affect you according to your personal health requirements, especially if you are prone to magnesium toxicity or gut disturbances.  

Overall, the benefits of magnesium on nerve pain are highly demonstrated by clinical trials but the administration techniques and dosages vary. There are good options available for magnesium to be bought over the counter, but these cheaper and more accessible options may be less effective than more costly or hospital-monitored treatments. Nevertheless, the health benefits of a magnesium-rich diet make adding more of the mineral (within the recommended limit) a worthwhile choice in managing pain.