Last week I wrote about premenstrual syndrome (PMS) and how calcium can be helpful to some women suffering from the condition.  I mentioned in the post that calcium and magnesium work well together and a combined supplement is preferable to a single nutrient supplement.  Magnesium and calcium work together in the body and magnesium is necessary for the efficient absorption and use of calcium but magnesium has benefits in PMS that go beyond simply acting in conjunction with calcium.

Back in 1973 some French scientists first reported that supplementing women with 400mg a day of magnesium seemed to help their PMS symptoms (1).  Studies followed which reported that the red blood cell levels of magnesium were significantly lower in patients who suffered with PMS than in those who did not suffer from the condition (2,3,4).  Subsequently supplementation trials in women with PMS have found that supplemental magnesium can reduce PMS symptoms (5,6,7,8).  Specifically magnesium supplements seemed to have a positive effect on symptoms related to mood (5), migraines (6) and fluid retention (7).

A small preliminary study (5) found that women who were being given a magnesium supplement had significant reductions in their total PMS symptoms in the second month of treatment compared to women taking the placebo.  It was also noted that a significant reduction in ‘negative mood’ occurred in women who were taking the magnesium compared to those taking the placebo.  Another study (7) found that, compared to placebo, magnesium supplementation at 200mg per day over two months significantly improved PMS symptoms, especially symptoms related to fluid retention such as breast tenderness, abdominal bloating, swelling of extremities and weight gain.

A more recent study (8) found that PMS symptoms improved during magnesium treatment.  The women were given 250mg magnesium for 3 months.  After three months the PMS score, as assessed by a specific research questionnaire called the Moos' Modified Menstrual Distress Questionnaire, was significantly lower than before therapy. During the same period, the mean PMS scores, as recorded in patients' diaries, also showed significant improvements . The authors conclude that magnesium supplementation was effective in reducing premenstrual symptoms in women with PMS in this preliminary study.

Magnesium is an incredibly important mineral and acts as a multi-functional nutrient in the body where it is present in all cells!  It takes part in around 300 processes in the body and is vital to many bodily functions such as energy production, nerve function, muscle relaxation, bone and tooth formation, heart rhythm and aids in the production and use of insulin (it is involved in blood sugar regulation which is thought to be an important factor in PMS)

Specific functions of magnesium relevant to PMS:
* Magnesium acts as a muscle relaxant (as it is needed for nerve to muscle signal transmission) and hence may be useful for fatigue symptoms.
* Many of the body’s energy pathways need magnesium – in this way it may be important to help restore vitality and prevent lethargy/tiredness.
* Inflammation is implicated in some forms of PMS (especially when breast tenderness is experienced).  Magnesium is needed for the metabolism of essential fatty acids, a good balance of fatty acids is needed in order to prevent inflammation.
* Low magnesium status may be responsible for promoting hormonal imbalance in women.  A low magnesium status may affect the aldosterone to oestrogen ration.  Enhanced levels of aldosterone can promote potassium and magnesium loss in the urine and may also promote sodium retention – this could induce fluid retention.
* As briefly mentioned above, magnesium is involved in blood sugar control.  Low magnesium levels can be implicated in two ways – by decreasing the ability of the liver to handle glucose and by increasing insulin secretion in response to glucose.  This may affect changes in appetite and cravings.
* The reduced dopamine (mood chemical in the brain) levels which are thought to be partly responsible for anxiety and irritability in PMS may be worsened by low magnesium levels.
* Low magnesium levels may enhance stress reactions and emotional stress such as anxiety can further increase our bodily need for magnesium.

In the UK it is currently recommended that women aim to include 270mg of magnesium per day into their daily diet.  However The National Diet and Nutrition Survey (NDNS) of adults aged 19-64 (9) found that quite a shocking number of women in the UK are not achieving adequate daily magnesium intakes with 74% of women age 19-64 not reaching the RNI (reference nutrient intake) for magnesium and 85% of 19-24 year old women not beaching the RNI for this vital nutrient.  Modern society does not eat as many whole grains, seeds, beans and nuts as in previous times and it is these sources that are rich in magnesium.  Processed foods contain little of this vital mineral.  Good dietary sources of magnesium include dried figs, almonds, hazelnuts, walnuts, cashew nuts, sunflower seeds and dark chocolate (minimum 70% cocoa solids!).  Wholegrains such as brown rice and oatmeal also contain good amounts.

The ideal amount of magnesium has yet to be determined for PMS improvement but practitioners often recommend a supplement of 200-400mg daily.  Symptoms seem to show improvement after 2-4 months.  It may well be worth supplementing with magnesium if you don’t routinely eat magnesium rich foods to see if it helps your symptoms – especially if you suffer from anxiety, low mood, stress, food cravings or water retention.  As mentioned in the post relating calcium and PMS – consider taking the two minerals together. 

1.Nicholas, A.  1973.  Traitement du syndrome  pre-menstrel et de la dysmenorrhee par l’ion magnesium.  First International Symposium on Magnesium Deficit in Human Pathology.  261-263.
2.Abraham, GE.  Lubran MM.  1981.  Serum and red cell magnesium levels in patients with premenstrual tension.  Am J Clin Nutr.  34:2364-2366.
3.Sherwood, RA et al.  1986.  Magnesium and the premenstrual syndrome.  Ann Clin Biochem.  23:667-670.
4.Rosenstein, DL et al.  1994.  Magnesium measures across the menstrual cycle in premenstrual syndrome.  Biol Psychiatry.  35:557-561
5.Fracchinetti, F. et al.  1991.  Oral magnesium successfully relieves premenstrual mood changes.  Obstet Gynecol.  78:177-181.
6 Fracchinetti, F.  et al.  1991.  Magnesium prophylaxis of menstrual migraine: effects on intracellular magnesium.  Headache.  31:298-301.
7.Walker, AF et al.  1998.  Magnesium supplementation alleviates premenstrual symptoms of fluid retention.  J Womens Health.  7:1157-1165.
8.Quaranta S et al.  2007.  Pilot study of the efficacy and safety of a modified-release magnesium 250 mg tablet (Sincromag) for the treatment of premenstrual syndrome.  Clin Drug Investig. 27(1):51-8.
9. Henderson L et al.  2003.  The National Diet and Nutrition Survey: Adults aged 19-64 years.  HMSO London.

Written by Ani Kowal