Highlights
- High dietary magnesium consumption lowers the risk of coronary heart disease by 10% by reducing blood pressure and maintaining normal heart rhythm.
- Magnesium lowers blood clotting factor levels which may cause stroke.
- By regulating glucose metabolism and reducing insulin resistance, magnesium lowers risk of type-2 diabetes.
Dr Fudi Wang, lead author from the School of Public Health at Zhejiang University, said, "Low levels of magnesium in the body have been associated with a range of diseases but no conclusive evidence has been put forward on the link between dietary magnesium and health risks. Our meta-analysis provides the most up-to-date evidence supporting a link between the role of magnesium in food and reducing the risk of disease."
Data from 40 epidemiological studies covering a period from 1999 to 2016 were analyzed to investigate associations between dietary magnesium and various diseases. Using a self-reported food frequency questionnaire or a 24-hour dietary recall, the levels of dietary magnesium were determined. The researchers performed a dose-response analysis for the effect of each 100mg per day increase of dietary magnesium, as the levels of magnesium used to define categories varied widely between the studies.
Approximately 25gms of magnesium is present in the adult body with 50% to 60% present in the bones and most of the rest in soft tissues. The blood serum has less than 1% of total magnesium and these levels are kept under tight control.
The normal serum magnesium concentrations range between 0.75 and 0.95 millimoles (mmol)/L. The kidneys maintain magnesium homeostasis and typically excretes about 120 mg magnesium into the urine each day. When magnesium status is low, urinary excretion is reduced.
Magnesium and Heart Disease Risk
The Atherosclerosis Risk in Communities study assessed heart disease risk factors and levels of serum magnesium in a cohort of 14,232 white and African-American men and women aged 45 to 64 years. After 12 years of follow-up, a 38% reduced risk of sudden cardiac death was observed in individuals with serum magnesium of least 0.88 mmol/L compared with individuals in the lowest quartile of 0.75 mmol/L or less.
Dietary Approaches to Stop Hypertension (DASH) diet rich in fruits and vegetables, low-fat or non-fat dairy products, and less fat overall was shown to lower systolic and diastolic blood pressure by an average of 5.5 and 3.0 mmHg, respectively. Though other nutrients such as potassium and calcium also reduce blood pressure, the independent effect of magnesium could not be determined.
Magnesium Cuts Stroke Risk
An additional 100 mg/day magnesium in the diet was associated with an 8% decreased risk of total stroke. In a meta-analysis of 7 prospective trials with a total of 241,378 participants, the risk reduction was observed especially in ischemic rather than hemorrhagic stroke. Von Willebrand factor levels were positively associated with the incidence of ischemic stroke. Low levels of serum magnesium increased the levels of Von Willebrand factor, increasing the risk of ischemic stroke.
Magnesium Reduces Diabetes Risk
Diets with adequate amounts of magnesium are associated with a lower risk of diabetes due to the important role of magnesium in glucose metabolism. Hypomagnesemia or serum magnesium levels less than 0.75mmol/L might cause insulin resistance, the inability of insulin to be utilized by the cells to absorb glucose for energy production. Diabetes leads to increased urinary losses of magnesium, and the inadequacy of magnesium might impair insulin secretion and action, thereby worsening diabetes control.
The meta-analysis involves observational studies which take into account the effect of other biological or lifestyle factors influencing the results. Though it is also not possible to determine if magnesium is directly responsible for reducing disease risk, the large size of this analysis provides robust data that were stable when adjusting for gender and study location. The findings reinforce the notion that increased consumption of magnesium-rich foods could be beneficial for overall health.
Reference:
- Magnesium - (https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/)