Magnesium

A 2017 systematic review by Boyle et al.¹ aimed to gather results showing whether taking a magnesium supplement could help people dealing with anxiety.   About half of the studies they looked at found that it helped people with either mild anxiety, PMS, or high blood pressure.  The authors concluded that more research should be done, but that the existing studies do point to the possibility that magnesium may be helpful for people with mild anxiety or PMS.  All of the studies measured anxiety subjectively.  Some of the studies included B6, hawthorn, or California poppy along with the magnesium, but they did not compare these combinations to the effect of magnesium alone.  Some studies compared to placebo (which also had a beneficial effect) while others compared to pharmaceutical medication.  The authors discuss the relevance of the placebo effect in their findings, and ways that future studies could be designed to account for this.  One study,² whose participants had PMS, used sorbitol as a placebo, which was on its own found to reduce symptoms, while other studies did not state the composition of the placebo used. 

 

One of the studies that did not find a benefit³ was looking at the acute stress and anxiety of students about to take an exam, which Boyle et al.¹ note would have different etiology from the chronic anxiety investigated by the other studies.  They also note that several of the studies were unpublished, and may not have been as well designed as they could have been.  Another study⁴ that did not find a benefit was looking specifically at postpartum anxiety, which may also have different contributing factors. 

 

The lowest dose that was found to be effective was 75 mg in a study by Hanus et al.⁵  Boyle et al.¹ note that different studies used different forms of magnesium which may have different bioavailabilities, and they suggest that more research should be done to determine which form is most effective.  They also suggest that researchers should compare the results of the intervention in people with adequate magnesium status with results in people who were deficient before beginning the treatment. 

 

A 2012 double-blind RCT by Abbasi et al.⁶ aimed to see if 500 mg of magnesium oxide could help older people get more sleep compared to placebo.  They surveyed 60-70 year olds to see how bad their insomnia was, and selected 46 to participate who had scored moderate to severe.  The other criteria the participants had to meet to be included in the study were things like stressful events that might contribute to insomnia and health conditions that might make it dangerous for them to take magnesium or that might affect the bioavailability of magnesium they ingested.  They also all had reported their existing consumption of magnesium to be less than 75% of the RDA. 

 

After eight weeks of treatment they repeated the survey to see if there was any improvement.  They found some significant benefits from the magnesium.  Not only did their survey show improvement, their bloodwork showed they had more melatonin and less cortisol, and they reported more physical activity than previously, likely because they were not as tired during the day. 

 

References

 

1. Boyle NB, Lawton C, Dye L. The Effects of Magnesium Supplementation on Subjective Anxiety and Stress-A Systematic Review. Nutrients. 2017;9(5). 
2. Walker AF, De Souza MC, Marakis G, Robinson PA, Morris AP, Bolland KM. Unexpected benefit of sorbitol placebo in Mg intervention study of premenstrual symptoms: implications for choice of placebo in RCTs. Medical hypotheses. 2002;58(3):213-220. 
3. Gendle MH, O’Hara KP. Oral Magnesium Supplementation and Test Anxiety in University Undergraduates. Journal of Articles in Support of the Null Hypothesis. 2015;11(2):21-30. Accessed February 3, 2023. 
4. Fard FE, Mirghafourvand M, Mohammad-Alizadeh Charandabi S, Farshbaf-Khalili A, Javadzadeh Y, Asgharian H. Effects of zinc and magnesium supplements on postpartum depression and anxiety: A randomized controlled clinical trial. Women & Health. 2017;57(9):1115-1128. 
5. Hanus M, Lafon J, Mathieu M. Double-blind, randomised, placebo-controlled study to evaluate the efficacy and safety of a fixed combination containing two plant extracts (Crataegus oxyacantha and Eschscholtzia californica) and magnesium in mild-to-moderate anxiety disorders. Current medical research and opinion. 2004;20(1):63-71. 
6. Abbasi B, Kimiagar M, Sadeghniiat K, Shirazi MM, Hedayati M, Rashidkhani B. The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial. J Res Med Sci. 2012;17(12):1161-1169.