Magnesium supplements

Preliminary double-blind studies suggest that regular use of magnesium supplements may help prevent migraine headaches, hearing loss caused by exposure to loud noises, and kidney stones, and help treat high blood pressure, angina, dysmenorrhea (menstrual cramps), pregnancy-induced leg cramps, and PMS (including menstrual migraines). People with diabetes are often deficient in magnesium; and according to some (but not all) studies, magnesium supplementation may enhance blood sugar control and insulin sensitivity in people with diabetes or prediabetic conditions. However, people with heart or kidney disorders should consult their doctor or dietitian before commencing magnesium supplements. If you think you need a supplement (due to chronic poor food intake or conditions/medications that leach magnesium from your body - check with your doctor or dietitian) it is advisable to avoid taking more than the recommended dietary intake (around 200mg is enough from supplements) and the balance should come from wholegrains, nuts and green vegetables. Also, your magnesium status can be checked with a blood test (red blood cell magnesium) more...

Magnesium important for preventing the "metabolic syndrome or syndrome x"

Metabolic syndrome is a condition that dramatically increases the risk of developing heart disease, diabetes, fatty liver and has even been linked to depression. One is considered to have metabolic syndrome if they have 3 or more of the five criteria:
1. abdominal obesity (waist circumference >102cm in men and >88cm in women),
2. high blood triglycerides (>1.69mmol/l)
3. low HDL cholesterol (<1.04 mmol/l in men and <1.29mmol/l in women)
4. hypertention (>130/85 mmHg)
5. insulin resistance (fasting glucose >5.5mmol/l and triglycerides/HDL cholesterol >1.8mmol - this ratio is a surrogate measure for dangerously elevated blood insulin levels.

Disturbingly, the prevalence of metabolic syndrome is soaring, paralleling that of other chronic disease epidemics. Currently over 5 million people in Australia have metabolic syndrome and an increasing number of adolescents are presenting with the condition. The causes of metabolic syndrome include: family genetics, stress, sedentary lifestyle, high refined carbohydrate diet/high glycaemic load diet, nutrient poor diet (especially low magneium diet), high calorie/fat diet, inflammatory disorders, hormone imbalance.

Magnesium deficiency has been linked to metabolic syndrome. Magnesium is required for carbohydrate energy metabolism (through phosphate transfer in the generation of ATP). Deficiency aggravates insulin resistance and may contribute to diabetes. In addition, magnesium is essential to the health of the cardiovascular system, regulating triglyceride and HDL cholesterol levels and maintaining blood vessel flexibility, a factor in hypertension. Deficiency has also been linked to heart disease, arrhythmia and diabetic retinopathy.

People with diabetes tend to have lowered body levels of magnesium due to increased excretion in the urine. There is now convincing evidence from research studies to suggest that eating magnesium rich foods (e.g wholegrains, nuts, legumes, fruit, vegetables and dairy foods) can reduce the risk of developing diabetes or to treat and control it if you have it. People who eat 2-3 serves of wholegrain foods each day are 20-30% less likely to develop diabetes compared to those who do not eat them. The DASH study encouraged participants to consume more fruit and vegetables (9 serves in total daily), 2-3 serves of low fat dairy and less fat. Blood pressure dropped and insulin action significantly improved (Ard et al, Diabetes Care 2004; 27: 340-7). Three newly published epidemiological studies from the US reported that a higher magnesium intake from food was associated with a lower risk of developing diabetes and lower fasting insulin levels .

In one study, researchers followed a group of young adults for 15 years, assessing their intake of magnesium and the incidence of metabolic syndrome. Among the participants, those who developed the syndrome had the lowest intake of magnesium.

Women need 400 milligrams magnesium per day and men 333 milligrams per day.
Magnesium is found mainly in wholegrain cereals (e.g 4 slices wholemeal bread has 90mg and 4 slices of white bread only 30mg), green leafy vegetables, brown rice, soybeans or tofu (1/2 cup 70mg), nuts (12 nuts 60mg), avocado/banana (40mg) and legumes (1/2 cup 40mg), salmon, oatmeal, and fortified cereal.

Magnesium intake and incidence of metabolic syndrome among young adults. He, K., Liu, K., Daviglus, M. L., Morris, S. J., Loria, C. M., Van Horn, L., Jacobs, D. R. Jr., Savage, P. J., Circulation 2006 Mar 27; 113:1675.

Diabetes care 2004, vol 27 pages 59-65 and 134-140; J Am Coll Nutr 2003; 22 (6): 533-8).

Food Sources of Magnesium - see our on-line book "Food Facts"

Magnesium important for strong bones but watch out for zinc supplements

Low bone mineral density is common in the community, with 50% of women aged 80 and over presenting with osteoporosis.

Most people know they need calcium and vitamin D to build strong bones, but new research reveals that omega 3 fats and magnesium are also important for maintaining bone mineral density to prevent the development of osteoporosis. Magnesium is also essential in many enzyme systems, is essential for muscle contraction and nerve function and helps in glucose metabolism and the release of energy (making it a particularly important mineral in diabetes as well).

A number of studies suggest that sub-optimal intake of magnesium is common and that subgroups such as people with diabetes and hypertension are commonly magnesium deficient. Magnesium deficiency is known to result in a decreased synthesis, release and action of the bone hormone 'parathyroid hormone' and 1,25 vitamin D.

In a study of 2038 adults aged 70 and over, (Ryder M et al.,2005), subjects who consumed the highest amount of magnesium (from their diet and/or supplements) experienced higher bone mineral densities compared to the people whose diets contained the least amount of magnesium. The association of high magnesium intake and bone density was statistically proven after controlling for factors which also influence bone density like calcium, vitamin D, body weight, smoking, alcohol, execrise, use of diureticis or use of oestrogen medication

Women need 400 milligrams magnesium per day and men 333 milligrams per day.
Magnesium is found mainly in wholegrain cereals (e.g 4 slices wholemeal bread has 90mg and 4 slices of white bread only 30mg), green leafy vegetables, brown rice, soybeans or tofu (1/2 cup 70mg), nuts (12 nuts 60mg), avocado/banana (40mg) and legumes (1/2 cup 40mg), salmon, oatmeal, and fortified cereal.

A high intake of zinc (>45mg/day) can decrease magnesium balance and potentially adversely affect bone mineral density. The recommended intake of zinc is 15 mg per day. Many people taking supplements ingest much more. In a carefully controlled study, people taking a 45 mg supplement (for a total of 53 mg from supplements and diet) had decreased magnesium balance. Twenty-five women with an average age of 65 years lived in a metabolic ward for 6 months so everything they took in and excreted was measured. Moderately high intake of zinc increased excretion of magnesium in both urine and feces. It also unfavorably altered two markers of bone formation in the women. People taking zinc supplements or using zinc lozenges to treat cold symptoms can get up to 150 mg zinc. These amounts can interfere with copper metabolism and depress HDL-cholesterol and immune functions. This is yet another example of why large doses of supplements are not better than getting your nutrients from a balanced diet.

Last Updated: April 2007