Magnesium is an essential trace element in the human body. It not only is essential in the growth of human bones and teeth, but also important for nerve impulse transmission and nervous communication in the human body. Moreover, Magnesium has been proved to be inversely associated with blood pressure levels, serum triglyceride levels, risk of diabetes mellitus and arrhythmia, all of which are risk factors of cardiovascular diseases.
Magnesium cannot be synthesised in the human body. The only way to obtain magnesium is through consumption. The Asian population was once considered to have sufficient magnesium intake, as most occupants in this region live on rice.
However, things have changed in the past few decades. Take the Japanese for example, from 1950-2002, there has been a dramatically reduction in dietary intakes of magnesium rich food, such as barley and millet, and a dramatically increase in protein or fat rich food, such as meat and fried food.
To be specific, Japanese adults consume 65 g of barley and millet and 20g of fat per day around 1950, while the corresponding amounts became three g and nearly 60 g in 2002.
At the same time, the prevalence of diabetes mellitus among the Japanese has increased dramatically (from three percent in 1950 to 20 percent in 2002). Based to this data, Professor Kuninobu Yokota from Jikei Univeristy suggested in the ‘Magnesium Hypothesis’ that deficiency of magnesium was associated with increased prevalence of diabetes mellitus in the Japanese.
Benefits Of Magnesium
The Japan Collaborative Cohort (JACC) Study , a large prospective cohort study (which involves 58,615 Japanese adults) with a median follow-up of 14.7 years, found that dietary magnesium intake was associated with lower risk of mortality from haemorrhagic stroke in men, and reduced mortality from coronary heart disease, heart failure and total cardiovascular disease in women. This is the first large-scale cohort study to report the beneficial effects of magnesium on cardiovascular outcomes in Asian population.
Beneficial effects of magnesium on cardiovascular disease may be explained by its blood pressure regulatory effect. Magnesium can prevent the entrance of calcium into the cells and thereby reduce contractility and nerve conduction in the heart. This means that magnesium intake can reduce the risk of heart failure.
Magnesium can also reduce risk of arrhythmia and vasoconstriction and the effect is probably due to reduced serum lipid concentration and decreased intracellular sodium concentrations through the activation of the cell membrane sodium-potassium pump.
Changes in lifestyle have resulted in the decline of traditional Asian food intake. With the ever-increasing incidence of mortality from cardiovascular diseases in Asian, a revival of magnesium rich food will be beneficial.
It is necessary and essential for us to know how to include magnesium rich food in our daily diets. For the Asian population, the major food sources for magnesium include milk and dairy products, fruits and vegetables, meat, fish and rice.
SOME STUDIES HAVE SHOWN THAT HIGHER CONSUMPTION OF WHITE RICE IS ASSOCIATED WITH A SIGNIFICANTLY INCREASED RISK OF TYPE 2 DIABETES, ESPECIALLY IN ASIAN POPULATIONS.
Milk & Dairy Products
More and more people have realised the value of milk and dairy products in the past few decades. Consuming milk and dairy products can prevent cardiovascular diseases because they are especially rich in calcium and magnesium.
In the JACC Study, calcium intake has been proven to be inversely associated with mortality from total stroke, while the inverse association with dairy calcium intake was apparent for total stroke, both haemorrhagic and ischemic.
For the human body, dietary calcium may be easier to absorb compared to other calcium resources. Milk and dairy products are also rich in magnesium, which is good for cardiovascular and cerebrovascular as it promotes the absorption of calcium.
Fruits and vegetables is another main source of magnesium for Asians. The JACC study has already shown that intakes of plant-based foods, particularly fruit intake, were associated with reduced mortality from cardiovascular diseases and other causes among Japanese men and women.
Most green vegetables, such as spinach, cabbage, lettuce, celery are rich in magnesium. Fruits like banana and apples are good options as well. Fruits and vegetables are beneficial for cardiovascular and cerebrovascular not only because they contains a good dosage of magnesium, but also because they are rich in fibres. Dietary fibre intake can protect us against coronary heart disease and total cardiovascular disease.
Moderate Meat Consumption
Meat is not necessarily the big evil here. It can be another important source of magnesium, iron and other trace elements. However, practice in moderation is the essential factor. Moderate meat consumption, up to around 100 g per day, was not associated with increased risk of mortality from ischemic heart disease or stroke or total cardiovascular disease among Japanese adults. Similar association was observed for the consumption of red meat (such as beef, pork and sausages), poultry, processed meat and liver when they were examined separately.
It is well known that the average life expectancy of the Japanese is the highest in the world. Healthy Japanese diets have contributed significantly to this achievement. The Japanese consume a lot more fish than other populations. Fish is also the main source of magnesium for Japanese.
Dietary fish intake is associated with cardiac electrophysiology in humans, including heart rate, atrioventricular conduction and ventricular repolarisation, with potential implications for arrhythmic risk. Fish benefits us not only because it is a source of magnesium, but also because it contains omega 3, which have been proven to decrease the risk of cardiovascular mortality.
Rice is a staple food in Asia. In Japan, rice provides 43 percent of carbohydrate and 29 percent of energy intake for the population. Though some studies have shown that higher consumption of white rice is associated with a significantly increased risk of type 2 diabetes, especially in Asian populations (Chinese and Japanese), a large cohort study has suggested that rice intake was inversely associated with mortality from coronary heart disease, heart failure, and total cardiovascular disease in Japanese men. It seems that rice is a good staple, but the amount consumed is very important.
A 16 week clinical trial in 76 Korean men has shown that isocaloric replacement of white rice with whole grains and legume powder (composed of 66.6 percent whole grains, 22.2 percent legumes, 5.6 percent seeds and 5.6 percent vegetables) led to significant reductions in serum glucose and insulin concentrations. Therefore, for Asians, in addition to rice, wheat can also a good alternative.
Dietary intakes of milk and dairy products, fruits and vegetables, and dairy products, moderate amount of meat, fish, rice and wheat can provide the magnesium that will protect us against cardiovascular disease. It is time for us to realise the value of these foods and try to enrich our daily diet with magnesium.