Magnesium Oxide Supplements: Cardinal remedy for Symptoms of Chronic Constipation

New research revealed that magnesium oxide supplements are useful for treating chronic constipation and that there is inadequate data to support the use of additional nutritional supplements like vitamin and kiwifruit supplements for treating constipation. The study results were published in the journal Neurogastroenterology & Motility. 

Chronic constipation is a burdensome gastrointestinal disorder that is diagnosed based on patient-reported symptoms such as infrequent stools, hard/lumpy stool consistency, straining, and incomplete evacuation. Over-the-counter (OTC) supplements are commonly used to treat constipation due to high rates of dissatisfaction among patients and low response rates to healthcare professionals. Previous literature suggested the use of fiber supplements, probiotics, and Synbiotics in chronic constipation but there is little evidence on the use of other supplements for constipation. Hence researchers conducted a systematic review and meta-analysis to investigate the effect of food, vitamin, or mineral supplements on stool output, gut transit time, symptoms, and quality of life in adults with chronic constipation. 

Electronic databases, manual searches of abstracts, and reverse citations were all used to find studies. Adults with persistent constipation were included in RCTs reporting administration of food supplements (such as fruit extract supplements), vitamin, or mineral supplements. Studies using whole foods, including fruits, were not included. The Cochrane RoB 2.0 tool was used to evaluate the risk of bias (RoB). A random-effects model was used to assess relative risks (RR), mean differences (MD), and standardized mean differences (95% confidence intervals [CI]). 

Key findings: 

• About 8 RCTs having 787 participants investigating kiwifruit (n = 3 RCTs), senna (n = 2), magnesium oxide (n = 2), Ziziphus jujuba (n = 1), and Malva Sylvestris (n = 1) supplements were included.
• Stool frequency or consistency was not influenced by Kiwi supplements.
• Nearly, 61% responded to senna and 28% to control, but were not statistically significant.
• Overall, 68% responded to magnesium oxide and 19% to control.
• Stool frequency and consistency were improved by Magnesium oxide supplements. 

Thus, this is the first study that evaluated that supplements containing magnesium oxide are useful for reducing the main signs and symptoms of persistent constipation. 

Take-home points:

• Supplements including senna and kiwifruit had little effect on signs and symptoms, however, results were based on a small number of investigations.
• The impact of food supplements (like kiwifruit supplements) and their whole food counterparts (like whole kiwifruits) on chronic constipation has to be further studied. 

Further reading: 

van der Schoot A, Creedon A, Whelan K, Dimidi E. The effect of food, vitamin, or mineral supplements on chronic constipation in adults: A systematic review and meta-analysis of randomized controlled trials [published online ahead of print, 2023 May 27]. Neurogastroenterol Motil. 2023;e14613. doi:10.1111/nmo.14613