Magnesium: What Does Research Tell Us?

May 1, 2013

Although prescription medicines have been shown to be effective in reducing the frequency and intensity of migraine headaches and migraine-related conditions (migraine equivalent neuropathies), the side effects of these medications make them unattractive to some people. As an alternative, high doses of oral magnesium taken daily have proven to offer relief with more tolerable side effects.

Low brain magnesium levels have been reported in at least 8 studies involving migraineurs. Several trials of magnesium as a preventive medicine for migraine headaches have been conducted. The study results are mixed, but this variability may be because both magnesium deficient and non-deficient patients were included. It has been estimated that about half of migraine patients have a magnesium deficiency and routine blood tests are not indicative of magnesium status. This corresponds with studies that have shown about 50% of people report reduction in intensity, and sometimes frequency, of migraine headaches. (Note: that success does not mean that all migraine headaches are eliminated.) It can be argued that empiric treatment in all migraine sufferers. Others have argued that there are more effective preventive strategies and this supplement might be more effectively used in subset populations of migraneurs, such as children, pregnant females and perimenopausal women.
There are variable magnesium formulations and no study has studied whether one formulation is superior to another. Evidence suggests that a high dose of magnesium is needed to be taken for 3-4 months before any benefit is measurable. Here is a sampling of published studies on this supplement.

  1. 20 subjects received 360 mg Mg++ pyrrolidone carboxylic acid divided in three doses and demonstrated efficacy.
    (Peikert A, Willimzig C, Kohne-Volland R. Prophylaxis of migraine with oral magnesium: Results from a prospective, multi-center, placebo-controlled and double-blind randomized study. Cephalalgia. 1996;16257-16263.)

  2. 81 adult women took 600 mg magnesium (trimagnesium dicitrate) daily demonstrated a 41.6% improvement in headaches versus 15.8% for placebo.
    (Pfafferath V, Wessely P, Meyer C, et al. Magnesium in the prophylaxis of migraine – A double-blind, placebo-controlled and double-blind randomized study. Cephalalgia. 1996. 436-440.)

  3. 69 subjects took 486 mg magnesium and no benefit was found over a 3-month period. Diarrhea was reported in 45.7% subjects taking magnesium, but also in 23.5% subjects taking the placebo.
    (Mauskop A. Editorial: Evidence linking magnesium deficiency to migraines. Cephalalgia. 1999; 19:766-767.)

The bottom line is that it might be worth trying magnesium and here are some guidelines:

People seem to get more relief from their symptoms with higher doses of magnesium (range is probably 300-600 mg in adults and 200-300 mg for prepubescent children – one study used 9 mg/kg in 3 divided doses with food), but side effects which are primarily gastrointestinal discomfort, diarrhea or constipation, increases with higher doses. Perhaps the best compromise is found at about 400 mg daily, but this dosage can be modified on an individual basis. The next challenge is to find a source of magnesium in the most convenient formulation. Most pharmacies stock 250 mg capsules, but specialty stores, such as GNC or WholeFoods, might have 400 mg capsules available. Other stores, such as Target pharmacies, will special order different magnesium formulations. One could experiment with taking a daily dose or dividing the dose and taking it at different times of the day. There are also specialty multi-vitamin capsules which contain higher doses of magnesium (400 mg) and riboflavin (400 mg), such as HeadacheFree.

For those who are disciplined enough to find their extra magnesium daily in their diet, remember that foods with fiber contain higher doses of magnesium.

  1. Bran (Oat, Wheat and Rice). One cup of oat bran contains 220 mg of magnesium. Consider adding bran to breads or cereal or cooking oatmeal.

  2. Nuts. Brazil nuts provide 500 mg per cup or 20 mg per nut. Almonds: 400 mg per cup; cashews 350 mg per cup; pine nuts 340 mg per cup.

  3. Seeds. A cup of dried or roasted squash or pumpkin seeds will contain over 700 mg of magnesium; a cup of watermelon seeds over 500 mg. Sunflower seeds: 450 mg per cup. Flax seeds: 39 mg per tablespoon; sesame seeds: 32 mg per tablespoon; sesame butter (tahini): 58 mg per tablespoon.

  4. Dark chocolate. Cocoa Powder provides more than 400 mg per cup. A chocolate bar provides about 30 mg per bar.

  5. Molasses contains >800 mg per tablespoon and is a good substitute for refined sugar in cakes and breads.

  6. Broccoli, squash, and green leafy vegetables. Soybeans may be the best. When dry roasted, a cup contains almost 400 mg. When boiled (edamame), they contain 100 mg per cup.

  7. Other sources include dairy products, meats and coffee.

  8. Water with a high mineral content, or “hard” water, is also a source of magnesium.