Reference
Jui-Hua Huang, Yi-Fa Lu, Fu-Chou Cheng, John Ning-Yuean Lee, Leih-Ching Tsai. Correlation of magnesium intake with metabolic parameters, depression and physical activity in elderly type 2 diabetes patients: a cross-sectional study. Nutr J. 2012 Jun 13;11:41.
Design
This cross-sectional study observed a representative subset of a diabetic population—210 type 2 diabetes patients aged 65 years and above. Patients were interviewed on lifestyle and 24-hour dietary recall. Assessment of depression was based on DSM-IV criteria. Physical measurements were assessed (height, weight, skin-fold thickness), along with blood pressure and blood and urine tests. Linear regression was applied to determine the relationship of magnesium intake with nutritional variables and metabolic parameters.
Key Findings
- 88.6% of participants consumed less than the dietary reference intake (DRI) for magnesium.
- 37.1% of participants had hypomagnesaemia.
- Metabolic syndrome and depression were associated with lower magnesium intake (P<0.05).
- A positive relationship was found between magnesium intake and HDL-cholesterol (P=0.005).
- Magnesium intake was inversely correlated with triglyceride, waist circumference, body fat percentage, and body mass index (P<0.005).
- After controlling for confounding factors, HDL-cholesterol was significantly higher with increasing quartile of magnesium intake (P for trend=0005).
- Waist circumference, body fat percentage, and body mass index were significantly lower with increasing quartile of magnesium intake (P for trend<0.001).
- The odds of depression, central obesity, high body fat percentage, and high body mass index were significantly lower with increasing quartile of magnesium intake (P for trend<0.05).
- Magnesium intake was related to high physical activity level and demonstrated lower serum magnesium levels.
- Serum magnesium was not significantly associated with metabolic parameters.
Magnesium testing in this study was done using serum magnesium, yet the authors concede that this test can be highly inaccurate and not definitive.
Practice Implications
In the Background section of their paper, the authors give a very thorough overview of the impressive nature of magnesium:
“Magnesium may be one of the most important factors for diabetes prevention and management. Indeed, magnesium has been associated with a number of chronic disease including, diabetes, hypertension, insulin resistance and lipid abnormalities. Magnesium deficiency
- is a common factor associated with insulin resistance and vascular disease,
- impairs energy metabolism efficiency and reduces the capacity for physical work,
- exerts negative effects on blood glucose homeostasis, and
- is independently assoc with depressive symptoms.
In addition, magnesium intake was inversely associated with the metabolic syndrome and risk of type 2 DM. High plasma triglycerides, abdominal adiposity, albuminuria and low HDL-cholesterol are associated with hypomagnesemia in diabetic patients. Double-blind placebo-controlled trials suggest magnesium supplementation may
- improve insulin sensitivity, reduce plasma cholesterol and LDL cholesterol, increase HDL cholesterol in DM patients,
- lower blood pressure in patients with essential hypertension, and
- improve resting ionic magnesium levels in physically active women.
- Furthermore, magnesium supplementation has been shown to be as effective as an antidepressant drug for treatment of depression in the elderly DM patients with hypomagnesemia."
The authors also state that type 2 diabetes mellitus is a major global public health problem and is increasing in aging populations. They say that magnesium intake may be one of the most important factors for diabetes prevention and management. The authors warn that the majority of elderly type 2 diabetes who have low magnesium intake may compound this deficiency with metabolic abnormalities and depression. Like most studies the authors conclude that more research needs to be done.
However, as clinicians we know enough about the benefits and the safety of magnesium to recommend it to all our diabetic patients and, in fact, to all our patients. This paper doesn’t go into why magnesium levels may be low in diabetics. The reason may be something as simple as the diuretic effect of high blood sugar and with each urination, some more magnesium is lost.
The RDA dosage is about 350 mg for adults. People with medical conditions like diabetes may need twice that amount.
The RDA for magnesium is about 350 mg in adults. People with medical conditions like diabetes may need twice that amount. There are many forms of magnesium, and several can be taken at once to make up the total elemental amount of magnesium: magnesium sulphate in Epsom Salts; transdermal magnesium oil; oral magnesium salts like magnesium citrate, chloride, and oxide; chelated forms of magnesium in which it is bound to an amino acid; and angstrom and pico-ionic forms with high absorption and no laxative effect.
I don’t usually recommend magnesium oxide since it’s only 4% absorbed, with the majority going through the intestines as a laxative. I also share Dr. Russell Blaylock’s concern about magnesium aspartate and magnesium glutamate because these 2 amino acids, when unbound, can become disruptive neurotransmitters.
Magnesium should be taken in several doses throughout the day, which will also diminish any laxative effect.
The only contraindications to magnesium supplementation are:
- Kidney failure. With kidney failure there is an inability to clear magnesium from the kidneys.
- Myasthenia gravis. Intravenous administration could accentuate muscle relaxation and collapse the respiratory muscles.
- Excessively slow heart rate. Slow heart rates can be made even slower, as magnesium relaxes the heart. Slow heart rates often require an artifiÂcial pacemaker.
- Bowel obstruction. The main route of elimination of oral magnesium is through the bowel.
