Low magnesium increases risk of heart disease

Researchers from the UMCG and TI Food and Nutrition have ascertained that ingesting too little magnesium via food increases a person’s risk of developing heart disease. Their findings are based on tests carried out on 24-hour urine samples from the people taking part in the longitudinal PREVEND study. The results were published on March 14 in the leading American Journal of Clinical Nutrition.

The mineral magnesium is needed for good muscle function and a normal heart rhythm. Previous studies based on questionnaires and blood tests came up with contradictory results about the link between magnesium and cardiovascular disease. The amount of magnesium in 24-hour urine corresponds directly with the amount of magnesium ingested via the food and absorbed by the body, which makes this method more accurate than questionnaires. 24-hour urine was collected from more than 7,500 people from Groningen, whose health was monitored for more than 10 years as part of the PREVEND study. On the basis of their findings, the researchers claim that magnesium is an independent risk factor for developing heart disease, including myocardial infarction.

Other factors

According to the researchers, low magnesium intake affects the development of heart disease in men and women of all ages. Factors such as smoking, overweight and obesity, alcohol consumption, diabetes and high blood pressure were not found to play a role in the health effects of magnesium. Also, the researchers discovered no direct link between magnesium consumption and mortality rates. They therefore conclude that low magnesium intake is not related to ill health in general, but has a specific effect on the development of heart disease.

Threshold effect

Only the 20% of PREVEND participants with the lowest level of magnesium in the urine had a 60% higher risk of developing heart disease. The other 80% all ran the same risk of heart disease, irrespective of the amount of magnesium in the urine. The researchers refer to this as a threshold effect: people who do not get enough magnesium via their food have a higher risk, but once above the threshold value, the amount of magnesium consumed no longer affects the risk of heart disease. Expressed in figures, the researchers found that cases of heart disease rose from 58 to 93 per 10,000 person-years among the group that consumed below the threshold value of magnesium.

Food

The researchers expect that roughly one fifth of the population would benefit from increasing their daily magnesium intake. These findings concur with the most recent research carried out by the National Institute for Public Health and the Environment (RIVM) into the eating habits of the Dutch population. During this study, which ran from 2007-2010, the RIVM ascertained that 20-30% of adults consume less than the recommended daily amount of magnesium. Magnesium is naturally present in green vegetables, legumes, fruits, nuts, grain and dairy products, and also in drinking water. A varied diet invariably includes magnesium-rich food.

The research was funded by TI Food and Nutrition in Wageningen and the Dutch Kidney Foundation.