
Background
Our body works by using the nutrients in our food to make things happen. We eat, we break down food, we absorb nutrients and the calcium goes into our bones, protein goes to our muscles, iron goes into the blood. Simple isn’t it? Well no, it’s actually quite complicated. In order for these things to happen lots of other things need to happen – we need to produce the digestive juices to breakdown the proteins, the blood to absorb the iron, the bone to absorb the calcium…. And each of those things involves processes of their own. All of the body’s functions involve reactions, and for these we need nutrients. Magnesium is the fourth most abundant mineral in the body and is involved in hundreds of these reactions as well as the activation of hundreds of enzymes – without it our bodies simply won’t work well.
Despite its importance, we don’t tend to hear much about this mineral. Below I explain some of the ways it is believed to benefit health, signs that you potentially have low levels of magnesium, and where to find it in food. I’ve tried to avoid getting too technical!
Some of the Roles and Benefits of Magnesium*
Energy
Some of the reactions that magnesium is involved in, include the conversion of food energy into useful energy. Magnesium also helps the cells throughout our body use that energy.
Magnesium is also believed to support sleep, which can also help us to feel more energised. There is evidence that it can even help improve the sleep of those experiencing insomnia. While further research is needed to understand how this works, it is thought that magnesium supports the sleep cycle and/or hormone production in the brain.
Bone Health
More than half the magnesium in the body can be found in bones. Studies suggest that low magnesium can contribute to the development of osteoporosis.
Magnesium increases the solubility of calcium and phosphate which are needed for bone structure. In addition, it has a role in the hormones released by the parathyroid glands which help to regulate the amount of calcium in our bones.
There is also a two-way relationship between magnesium and Vitamin D. We need vitamin D to help us absorb calcium, but it also helps us to absorb magnesium – and to use vitamin D we have to convert it to a useable form, a process that requires magnesium.
Heart Health
Did you know that the level of calcium in our body also affects our heart health? High levels of calcium in the blood, can build up in the arteries increasing the risk of coronary artery disease and heart attacks. By helping us absorb the calcium into our bones and cells, magnesium helps to reduce the calcium in our blood. It also supports the heart through its role as a calcium channel blocker, stopping calcium entering the heart and arteries.
Magnesium supports blood pressure and heart rhythm, supports blood clotting and has an anti-inflammatory role.
Brain Function (including mood and migraines)
Again, the relationship between magnesium and calcium has a role in the health of the brain. Calcium has a role in memory formation and the signalling processes in the brain – magnesium helps to regulate it.
Magnesium is also important for our neurotransmitters (our chemical messengers that are essential for us to function) and the blood-brain barrier, which helps control the substances that pass into the brain from our blood.
Inflammation in the brain may be increased by magnesium deficiency. While inflammation can be helpful in the event of an injury, long-term inflammation is not. Long-term neuroinflammation has been linked with mental health problems such as schizophrenia, depression, anxiety and mood disorders.
It has been suggested that magnesium also has a role in neurodegenerative diseases. Studies looking at its role in specific diseases, including Alzheimer’s Disease, Parkinson’s Disease and MS are ongoing.
Studies have found that individuals who suffer from migraines often have lower levels of magnesium than those that don’t. Magnesium’s importance to processes within the brain that are associated with migraines is likely to be the link here, rather than it being a direct association.
Muscles (including digestion)
Around a quarter of the magnesium in the body can be found in the skeletal muscles. It is important for muscle function as it helps muscles to relax. Again, the balance between calcium and magnesium is a factor in this function.
Magnesium deficiency has been identified in individuals experiencing severe muscle cramps, muscle weakness and diseases related to the nerves controlling the muscles (neuromuscular dysfunction). Symptoms of neuromuscular problems may include muscle weakness, pain, numbness and difficulty moving.
A good magnesium intake may help people to perform better when exercising. It is thought to help move blood sugar into the muscles, and dispose of lactate. (The evidence regarding this is mixed).
Of course, our gut works through muscle action as well. The muscle movement helps our food and stools to move through the body. In addition, magnesium helps to attract water into stools to soften them and make them easier to pass. If you experience constipation and feel bloated, low magnesium may be a consideration.
Blood Sugar Balance
We hear about controlling our fat and carbohydrate intake to help manage our weight (associated with diabetes risk), and our insulin requirements but we don’t tend to hear about vitamins and minerals required to manage our blood sugar. Unsurprisingly given the topic of this post, magnesium is important here too.
We use magnesium to make insulin and to respond to insulin. Without these two actions sugar stays in the blood. Studies have shown that low magnesium is associated with insulin resistance (where your cells are unable to use the insulin you produce). Unfortunately, individuals with insulin resistance excrete more magnesium in their urine further lowering their levels.
Magnesium and Asthma
Magnesium sulphate may be used intravenously in hospitals for people suffering an asthma attack. It works by relaxing the muscles in the lungs and opening up the airways. It might also be used for individuals with COPD.
From a dietary perspective, studies have reported low magnesium levels in those with asthma. A study in 2022 looked at the anti-inflammatory properties of magnesium and found that it can support lung function and reduce asthma symptoms.
Other studies looking at nutrition and asthma also found selenium, and vitamins A, C, D and E all to be beneficial. All can be obtained from a diet rich in a variety of whole foods. Sulphites (often applied to non-organic dried fruit and other packaged items, as well as being used in wine production) may aggravate asthma symptoms.
To date human studies in this area appear to have all been small-scale and mainly focused on the IV treatment, but combined the results are more convincing. While increasing magnesium intake may be helpful to asthmatics, it should not be considered a method of treatment or seen as a replacement for prescribed medical interventions.
Signs of Low Magnesium*
So to summarise, magnesium helps to maintain nerve and muscle function, our bone strength, and our immune systems. It also helps our heart function, supports energy metabolism, hormone production, and helps to maintain blood sugar levels. Why do we not hear more about it?!
In the National Diet and Nutrition Survey published by the National Office of Statistics in 2012, the average intake of magnesium (as well as many other nutrients) amongst the UK children aged 11-18 years and adults aged 19-64 years were below the recommended levels. In fact, girls in this age group were getting just 64% of the recommended intake, and boys 79%. At this age, it is not just the growth and immediate health of the children that is affected – they are learning the eating habits that they are likely to take into adulthood (and then pass on to their own children). Their health status will also contribute to their health as adults. In females aged 19-64 years the level was 84% of the recommended intake, for men the level was 96%.
It’s important to remember at this point that the recommended intake is the level at which we will simply maintain general good health – below that level we risk deficiency. However, our lifestyles and health may well require higher intakes to meet our actual needs – a concern given average intakes are below even the recommended level!
Beyond the health conditions above (which can all have different or multiple causes and should therefore be checked out by a suitably qualified professional), here are a few signs that you could benefit from increasing magnesium in your diet:
- Loss of appetite
- Lethargy and fatigue
- Depression
- Seizures
- Low stress tolerance, irritability and hypertension
- Poor blood sugar balance
- Nausea
- Vertigo
- Progressive muscle weakness
- Muscle cramps.
The condition of severely low magnesium known as hypomagnesemia may contribute to cardiac arrhythmias.
For some people low magnesium intake may be due to increased need, low intake or reduced absorption (for example due to medication or health conditions).
However, don’t reach for the supplements without first checking your intake and any medical interventions you are receiving. Too much magnesium can also have negative effects, as can interactions with some medications. Unlike supplements, dietary magnesium is less likely to result in excess or interactions with medications (it’s still worth getting this checked to be safe though!). To boost your magnesium intake naturally through your diet, see below.
*Note: Each of the health conditions and symptoms listed here can have more than one potential cause. Make sure you consult with a medical professional for diagnosis and medical review of possible causes or your ailments.
How to Increase Your Magnesium Intake Through Food
Great sources of magnesium to incorporate into every meal are:
- Leafy green vegetables
- Nuts
- Seeds, including pumpkin and sunflower seeds
- Whole grains, including oats, quinoa, wholemeal bread and brown rice
- Pulses and legumes, including kidney beans, chickpeas and lentils
- Tofu
- Fruit, such as dried apricots and bananas, and fresh avocado and blackberries
- Cocoa (70%+ dark chocolate is a good source)
How?
Here’s a few suggestions of how you could incorporate these foods:
- start your day with an oat-based breakfast adding seeds and fruit; or a smoothie including avocado and/or banana
- have a handful of nuts for a snack
- swap your pre-sliced white bread for fresh wholemeal bread, and add some salad and a couple of dried organic apricots as dessert. If you have soup, add some pumpkin seeds.
- have an afternoon snack of veg sticks with houmous, or a couple of squares of dark chocolate
- swap white rice in your evening meal for brown rice (or white pasta for wholemeal pasta) and include some pulses, legumes and/or tofu into your stir-fry, curry or sauce. If you can, include some leafy greens too.
Meat, fish and dairy do not contain as much magnesium as plant foods although they do contain some which will add to your overall intake. The best fish sources are salmon, halibut, mackerel and pollock; while the best dairy is cheese and yoghurt.
Of course, the amount of magnesium we eat is only part of the story. We need to be able to absorb it. The great thing is, eating a varied diet rich in whole foods is great for helping us make the most of the magnesium we consume. So boosting your magnesium intake through a good diet could also help you absorb more of it too!
References/Further Reading
- Magnesium: Biochemistry, Nutrition, Detection, and Social Impact of Diseases Linked to its Deficiency – Fiorentini, et al (2021) – https://pmc.ncbi.nlm.nih.gov/articles/PMC8065437/
- Magnesium and the Brain: A Focus on Neuroinflammation and Neurodegeneration – Maier, et al (2022) – https://pmc.ncbi.nlm.nih.gov/articles/PMC9820677/
- The Role of Oral Magnesium Supplements for the Management of Stable Bronchial Asthma: A SYtematic Review and Meta-analysis – Abuabat, et al (2019) https://pmc.ncbi.nlm.nih.gov/articles/PMC6379356/
- “Oral Magnesium Supplementation for Insomnia in Older Adults: A Systematic Review & Meta-Analysis” – Mah and Pitre. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8053283/
- National Diet and Nutrition Survey: Headline Results from Years 1, 2 and 3 (combined) of the Rolling Programme 2008/09 – 2010/11 – Tables and Appendices – Table 5.20 – https://assets.publishing.service.gov.uk/media/5a7c159ee5274a1f5cc75b06/NDNS_Tables_and_Appendices.zip (this link allows you to download the tables and appendices – to view the report documents go to https://www.gov.uk/government/statistics/national-diet-and-nutrition-survey-headline-results-from-years-1-2-and-3-combined-of-the-rolling-programme-200809-201011)