Higher magnesium intakes associated with a reduced risk of stroke

‘Stroke’ is a term used to describe the manifestation of death in part of the brain. It most common occurs as a result of blocking off in one or more arteries – these are called ‘ischaemic’ stokres. More rarely, strokes can be caused by arteries bleeding into the brain (so-called ‘haemorrhagic’ strokes).

Earlier this week saw the on-line publication of a study which assessed the relationship between magnesium intake and risk of stroke [1]. It found that for each 100 mg increase in magnesium intake, risk of stroke was 8 per cent lower. This association was only found for ischaemic stroke. Taken in isolation, each 100 mg increase in magnesium intake was associated with a 9 per cent reduced risk of ischaemic stroke.

This study is epidemiological in nature, and therefore cannot tell us if magnesium is truly protective for ischaemic stroke (it might be that the association is just that – an association – and that the relationship is not ‘causal’). However, the authors of this paper speculate on a few mechanisms by which magnesium might protect against stroke including:

  1. an ability to lower blood pressure by a small put potentially important amount
  2. a relationship between higher magnesium levels and reduced risk of type 2 diabetes (diabetes is a risk factor for stroke)
  3. an ability for magnesium to bring about favourable changes in blood sugar and blood fat levels
  4. an ability to reduce oxidation of blood fats (oxidation of blood fats – ‘lipid peroxidation’ – is believed to make them more toxic to the body)

As an aside, I take magnesium everyday (unless I forget). I take it because if I don’t, I get problems with muscular cramp and some spasm in my gullet (oesophageal spasm). I also, as it happens, have quite a strong family history of stroke. This latest evidence gives me another potential reason to keep up a good intake of magnesium.


1. Larsson SC, et al. Dietary magnesium intake and risk of stroke: a meta-analysis of prospective studies. Am J Clin Nutr 28 December 2011 [epub ahead of print]

12 Responses to Higher magnesium intakes associated with a reduced risk of stroke

  1. Liz Smith 30 December 2011 at 7:18 pm #

    This interests me as I cannot take magnesium tablets but get Magnesium oil and spray it on my skin. They say this is better as it enters the system faster than pills. I am currently getting lots of cramp in my legs and feet and migraines. Spraying the oil during either of these attacks works fast. But I wonder how often one has to do this when no attacks are taking place?

    I read it was a good idea to incorporate Magnesium when taking Vit D3 but haven’t been able to isolate HOW much and when to take it. I wondered if taking Epsom Salts baths would be as good as the oil, does anyone have the information please and thank you.

  2. patricia 30 December 2011 at 7:53 pm #

    having had a stroke two years ago, Im very interested in preventing a further episode. What foods contain Mg? and is it in a form able to be used by the body? If a supplement is more efficiently absorbed, which one do you recommend? please advise, thankyou

  3. Terry 30 December 2011 at 8:26 pm #

    Almond nuts are an excellent source of magnesium, which is quickly absorbed into the body. Sainsburys do a large 300 gram bag which I make a point of having in the house on a continuous basis. Almond nuts are delicious – and filling.

    If you want supplements, I’d suggest Dr’s Best Magnesium tablets at http://www.bodykind.co.uk.

  4. kem 30 December 2011 at 10:36 pm #

    We have been using magnesium chloride (the ingredient in the very expensive Ancient Minerals magnesium oil). A 25kg bag of crystals is NZ$14 vs $40 for a 250 ml bottle of liquid. It is a product used for dairy cattle supplementation… those girls need lots of magnesium.

  5. Diana1 30 December 2011 at 10:57 pm #

    I suffer from painful leg cramps at night and have a soak in a hot bath with a smallish cupful of Epsom Salts added about once or twice a week. I find it effective in keeping my cramps reasonably at bay. An additional advantage of using Epsom Salts is that they contain sulphur and that is now coming up the agenda – see for instance various items with Stephanie Seneff on the Mercola blog.

  6. Gabriella 31 December 2011 at 12:08 am #

    Hi Liz –
    re. magnesium content of foods. Please click on this: http://healthyeatingclub.com/info/books-phds/books/foodfacts/html/data/data5d.html

    By the way, cocoa powder is one of the richest source of magnesium and among nuts Brazil nuts are the richest. Wheat bran also contains quite a bit of it. Among fruits, the richest sources are dry fruits like figs, dates and apricots. And get this: table salt is very rich in magnesium as well.
    But check it out by yourself! Very interesting!
    Happy New Year! Gabriella (from Santa Barbara, California)

  7. ELIZABETH BRADSHAW 31 December 2011 at 2:09 am #

    Fascinating, I take magnesium because was having cramps and chocolate cravings, these no longer occur with regular magnesium, and I also seem to digest my food better.

  8. hilda glickman 31 December 2011 at 2:45 am #

    Magnesium has so many functions in the body but many people don’t eat high mag foods such as nuts and greens while eating a diet high in calcium which upsets the balance.

  9. rox 31 December 2011 at 6:47 pm #

    I started taking Floradix magnesium liquid (available from Victoria Health and Amazon in the UK) when vit D caused leg cramps, it helps alleviate general aches and pains like neck ache and menstrual cramps too. I do eat green veg, mixed nuts and dark chocolate, which all contain magnesium. For me Floradix works better than magnesium salt baths.

  10. patricia 1 January 2012 at 10:04 pm #

    thankyou one and all for the info re Mg, I have made a note of all the suggestions and will follow them up, Patricia

  11. Ajana 3 January 2012 at 8:44 am #

    I take magnesium daily to prevent migraines. I also read of a study which looked at giving magnesium intravenously to patients within a very short time frame of having a stroke – showed positive results. For a repeated study, the patients were given the magnesium much later and it was not effective.

  12. Tom 4 January 2012 at 7:58 pm #

    I take magnesium most days, in the more palatable form of Lindt 85%!

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