Could Magnesium Help Prevent Cancer?

Magnesium is one of the most abundant minerals in the body, with the adult body containing around 25g. It is required for over 300 processes, such as energy production, blood pressure regulation and the production of one of our own antioxidants, glutathione (the 'master' antioxidant). But can such an everyday substance prevent one of the most serious health issues, cancer?

Source: Krish Dulal

It turns out that research has suggested a protective effect of magnesium against cancer. In a study involving women from the Swedish Mammography Cohort, those in the highest quintile for magnesium intake had a 40% lower risk of colon cancer than women in the lowest category. However, measurement errors were found which are most likely to have resulted in an underestimation of this protective effect. This study followed more than sixty thousand women for almost 15 years, and found that the daily magnesium intake associated with a 40% lower colon cancer risk was 255mg or over. The intake that this was compared to was 209mg or under.

The protection that magnesium may give against cancer is not limited to Sweden. The Iowa Women's Health Study followed over 41,000 women for 17 years, and found that a magnesium intake of over 351mg every day was linked with a 23% reduced risk of colon cancer, compared to an intake of under 245mg. Additionally, a Japanese study followed over 87,000 men and women aged 45 to 74 for eight years, in order to see whether or not magnesium protected them against colon cancer in this context. For men, an intake of at least 327mg of magnesium a day reduced the risk of colon cancer by 52%, compared to intakes of 238mg or less. No effect was seen in women this time, but the female participants were more active, weighed less, drank less alcohol and had a lower diabetes risk than the men. Because of these factors, the men already had a higher risk, and so more potential benefit. It was pointed out that insulin resistance is a risk factor for colon cancer, as insulin may stimulate the growth of the abnormal cells. Research on animals and cell lines has also found that magnesium deficiency can increase the risk of cancer. For example, lead is more likely to cause leukaemia in magnesium deficient rats. Multiple studies on humans have shown that parental exposure to lead and petrol could raise the risk of childhood leukaemia.

But how can we increase our magnesium intakes? The best way is to eat magnesium-rich foods, which contain other nutrients with a range of health benefits of their own. For example, one ounce of dry-roasted almonds contains 80mg of magnesium, 20% of the recommended daily value of 400mg. Half a cup of boiled spinach comes very close to this, at 78mg. An ounce of dry-roasted cashews has 74mg of magnesium, half a cup of cooked black beans has 60mg, and half a cup of shelled, cooked edamame contains 50mg of magnesium. As for supplementation, different forms have different rates of absorption. Magnesium bound to aspartate (an amino acid), citrate, lactate or chloride is absorbed and used much more readily than magnesium sulphate or oxide. Taking zinc at the same time may also impair absorption. With cancer being so common and so serious, why be complacent with a poor diet, low in magnesium and other protective nutrients?