Tuesday, 24 February 2015

Magnesium


Magnesium is the fourth most abundant mineral in the human body.  It is required for over 300 biological processes.  It’s really important we consume enough magnesium in our diet.  The reason? It’s involved with lots of important bodily processes including: muscle function, sleep, mood and mitochondrial repair and replication.  It’s also been shown to be protective of cancer and heart disease.  It is absorbed in the small intestine and excreted by the kidneys
Mitochondrial repair and replication.

I want to hit this topic first, as I think this might be the most important role magnesium plays within our body.  It’s one of the main underlying mechanisms behind the benefits of magnesium.  You may need to bear with me here while I explain some background information.

The first thing I should probably do before explaining how magnesium impacts mitochondrial repair and replication, is explain what a mitochondrion is.  Pretty much every cell in the human body has a mitochondrion.  They are known as the “cell powerhouses” as they are the site in which most ATP is produced.  ATP stands for adenosine triphosphate which is essentially the currency for energy in the body.  So the more mitochondria you have, and the more efficient they are at functioning the more energy you can produce.  Increased numbers of mitochondria is usually brought on as part of a training effect from physical activity.  So someone like Mo Farah probably has one or two more mitochondria than say myself.

Now in order to increase numbers of mitochondria it requires your existing mitochondria to replicate their genome.  This is where magnesium comes in.  The enzymes required for mitochondria to replicate its self are magnesium dependent.  So the magnesium allows these enzymes to do their job.  So without enough magnesium your body will struggle to replicate its mitochondria, therefore compromising physical performance in athletics or everyday activities.

Another way to increase energy production is to increase your current mitochondria’s efficiency.  Every day we expose ourselves to or create oxidative stress, this can be through physical activity, pollution, smoking etc.  This oxidative stress damages our mitochondria, reducing their ability to produce ATP.  Not to worry though because our bodies are awesome and they can repair this damage using the same magnesium dependent enzymes I have previously mentioned.
Basic Structure of the Mitochondria


Cancer protection
A study took place in France following 4035 men between the ages of 30-60 for 18 years.   The men who had higher levels of magnesium had a 40% decrease in relative risk for all-cause and cardiovascular deaths and by 50% for cancer deaths, compared to those with the lowest magnesium levels.  The good thing about this study as far as quality goes is that it controlled for a number of other major risk factors for cancer.

Studies into levels of magnesium in drinking water have found that higher magnesium is inversely correlated with deaths from breast, prostate and ovarian cancers.

Now this data is very promising but what makes it better is a clear mechanism between adequate magnesium levels and cancer prevention.  That is exactly what I hope to explain now.  So one of the ways a cell can mutate and become potentially cancerous, is due to replication errors when the cells (specifically stem cells) attempt to replicate themselves.  During replication a stem cell must replicate the entire genome of the cell.  The enzymes required for this process are called DNA polymerase’s.  Now these enzymes are far from perfect, in fact on average 120,000 sequence errors are made per cell division.  Fortunately 99.9% of these errors are taken care of by a proof reading type system performed by DNA polymerase, and guess what DNA polymerase is dependent on….you guessed it magnesium.  So consuming adequate amounts of magnesium will maximise the efficiency of DNA polymerase and therefore reduce the likelihood of replication errors.  This mechanism gives a strong scientific link to the epidemiological data from France.

I hope I haven’t lost all of you at this point as this took me quite some time to get my head around.  The credit goes to Dr Rhonda Patrick’s for breaking this down in a way I could understand, she is definitely worth a follow on twitter @foundmyfitness.

Cardiovascular Disease
In a large review article comprising of 16 studies and 313,041 participants, higher magnesium levels were associated with a 30% lower risk of CVD.  This relationship was observed at a daily intake of 250mg/day.  Another review found a 15% reduction in cardiovascular disease between the highest and lowest groups of magnesium levels.

There are mechanism’s behind this association too! Magnesium has been shown to enhance endothelium dependant vasodilation, improve lipid metabolism, reduce inflammation and inhibit platelet function 

Muscle Function and Energy Production

Magnesium is required for the active transport of calcium across cell membranes.  This is important as calcium is essential with muscle tissue for it to contract. 

Magnesium acts as a cofactor for crucial enzyme called ATPase’s which are needed for production of ATP within the mitochondria.

Transdermal Magnesium for DOMS
An ever increasing method for combatting the dreaded DOMS is applying transdermal magnesium.  This can be done by directly spraying magnesium onto muscles or soaking in a bath with magnesium flakes or bath salts.

I have heard a lot about this method from various sources and have used magnesium flakes myself on a few occasions.  Personally I did feel a benefit from using the magnesium flakes it certainly aided my sleep and I noticed considerably less DOMS following a legs session.  As I have been having a look through the literature it seems there is a lack of studies into the effects transdermal magnesium has on DOMS.  A lot of the studies that have been done tend to have an affiliation with a specific product, which always screams bias to me.  Now that doesn't t mean they have falsified results or anything, you couldn't get away with that.  Their results are still very positive, but experiments or stats can sometimes be set up in a certain way to make positive or negative result more likely.

So for now all I will say is yes there is some evidence to suggest transdermal magnesium can alleviate symptoms of DOMS and aid sleep.  Is there enough research to make a definitive conclusion?  As far as I can tell (I may be wrong) no quite at the moment, but none the less I have experienced a benefit from using them myself, so will probably continue to use them.  So if you do exercise regularly or find yourself suffering from DOMS, maybe give transdermal magnesium a go feel free to comment and let me know how you get on. Also if you know of any studies on transdermal magnesium, please leave me a comment.  I should also point out when using magnesium bath salts its important to get the temperature right, I believe 50 degrees centigrade is normally recommended.  If that baths isn't at the right temperature your body will not absorb the magnesium. 


Sleep, Mood and Migraines
Sleep quality, mood and migraines have many things in common, one is levels of serotonin.  Serotonin is a neurotransmitter.  Low levels of serotonin can result in poor sleep, low mood and migraine incidence.

Serotonin is produced by converting the amino acid tryptophan, first to 5HTP then serotonin.  Part of this sequence is reliant on both vitamin B6 and magnesium, as well as some other micronutrients.  Serotonin is a precursor hormone melatonin, this is the hormone that, for lack of better words, “controls” our circadian rhythm.  This is why magnesium is frequently in supplement formulas that aid sleep or mood e.g. 5HTP complexes.
The additional mechanism tying magnesium to migraines is that it relaxes blood vessels in the brain, and inhibits the ability of calcium to constrict blood vessels     
Process of creating serotonin from protein in the diet all the way to the neurotransmitter itself

Food
So now we know some of the functions magnesium has in the body and why it’s so important, so how do we get it in the diet?  What are the best sources?  Foods rich in magnesium are…green leafy vegetables, nuts, avocado, cocoa, grains and seeds.  I should make it clear that throughout this post I have used the phrase “adequate” very deliberately when referring to levels of magnesium, this is because like any other mineral you can certainly consume too much.  The current UK dietary reference value is 300mg per day.  This is the amount of magnesium required to meet the needs of 97.5% of the population.  The only way to really get to know your individual requirements would be to get blood work done.  Below you can see a table with some examples and their magnesium content per 100g.

Food Item
Magnesium per 100g (mg)
Kale
47
Spinach
79
Avocado
29
Oats
177
Brazil Nuts
376
Almonds
268

Something to bear on mind with the food sources of magnesium is something called phytic acid.  Nuts and grains contain phytic acid which can inhibit the absorption of certain minerals.  This is important as for the most part it’s not a case of “you are what we eat” it’s more like “you are what you absorb”.  So the magnesium in these food sources could be less available to the body.  For me personally I try and get as many servings of green leafy vegetables as I can.  The magnesium is more bioavailable and you have a ton of other micronutrients packed in their too!

Supplementation
Before supplementing it’s always best to consult a doctor, just to make sure it’s safe for you as an individual. It’s more than feasible to get all the magnesium you need through real, wholefood sources. If you do want to supplement with magnesium, magnesium citrate has been shown to be the mote bioavailable form of magnesium.  Try and avoid enteric coated supplements, as the coating can inhibit absorption by up to 67%.  Finally, if you do supplement with magnesium consider taking it in conjunction with calcium in a 2:1 ratio in favour of calcium.  This is often recommended as calcium and magnesium are absorbed through similar pathways. 

Conclusion
So magnesium is an essential mineral, that we should consume around 300mg per day.  There is some very strong and robust mechanistic and epidemiological evidence that adequate magnesium intake can be protective of cancer can heart disease. 

Magnesium is a key component of muscle function.  So anyone who is active really needs to make sure they get their daily dose of magnesium.  There is some evidence that transdermal magnesium can aid with DOMs, however personally I think more research could be done in this area.
Magnesium is required for serotonin production, therefore impacting sleep, mood and potentially migraine incidence.

I should finish off my saying I have only really touched on some of the main functions of magnesium in the body.  Honestly in the process of reading around for this post I found you could probably dedicate an entire book to the processes magnesium is involved with, and the benefits of consuming enough of it has.

So load up on that green leafy veg and get your magnesium in!

References
BATRA, V., BEARD, W., SHOCK, D., KRAHN, J., PEDERSEN, L. and WILSON, S. (2006). Magnesium-Induced Assembly of a Complete DNA Polymerase Catalytic Complex. Structure, 14(4), pp.757-766.

Boska, M., Welch, K., Barker, P., Nelson, J. and Schultz, L. (2003). Contrasts in cortical magnesium, phospholipid and energy metabolism between migraine syndromes. Headache: The Journal of Head and Face Pain, 43(4), pp.425-425.

Chiu, H. F., Chang, C. C., & Yang, C. Y. (2004). Magnesium and calcium in drinking water and risk of death from ovarian cancer. Magnesium research,17(1), 28-34.

Chun-Yuh Yang, Hui-Fen Chiu, Bi-Hua, (2000). CALCIUM AND MAGNESIUM IN DRINKING WATER AND THE RISK OF DEATH FROM BREAST CANCER. Journal of Toxicology and Environmental Health, Part A, 60(4), pp.231-241.

Chun-Yuh Yang, Hui-Fen Chiu, Shang-, (2000). CALCIUM AND MAGNESIUM IN DRINKING WATER AND RISK OF DEATH FROM PROSTATE CANCER. Journal of Toxicology and Environmental Health, Part A, 60(1), pp.17-26.

Del Gobbo, L., Imamura, F., Wu, J., de Oliveira Otto, M., Chiuve, S. and Mozaffarian, D. (2013). Circulating and dietary magnesium and risk of cardiovascular disease: a systematic review and meta-analysis of prospective studies. American Journal of Clinical Nutrition, 98(1), pp.160-173.

Geissler, C. and Powers, H. (2005). Human nutrition. Edinburgh: Elsevier/Churchill Livingstone.

Leone, N., Courbon, D., Ducimetiere, P. and Zureik, M. (2006). Zinc, Copper, and Magnesium and Risks for All-Cause, Cancer, and Cardiovascular Mortality. Epidemiology, 17(3), pp.308-314.

Qu, X., Jin, F., Hao, Y., Li, H., Tang, T., Wang, H., Yan, W. and Dai, K. (2013). Magnesium and the Risk of Cardiovascular Events: A Meta-Analysis of Prospective Cohort Studies. PLoS ONE, 8(3), p.e57720.

Zidverc-Trajković, J., Pavlović, A., Jovanović, Z., Šternić, N. and Kostić, V. (2001). Efficacy of intravenous magnesium sulfate in severe migraine attacks. J Headache Pain, 2(2), pp.79-82.


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