The Journal of Nutrition published a study by doctors at the National Cancer Center in Tokyo, Japan involving 40,000 men and 46,000 women, an reassuringly large sample for testing.
The 40,830 men and 46,287 women were followed up for 8 years. This study did not include an analysis of supplement use among participants. It focused strictly on magnesium intake from foods and dietary sources.
The study showed that higher intake of dietary magnesium was strongly associated with a decreased risk of colorectal cancer (colon cancer) in men. The study, however, showed no such correlation among the women. Investigators speculate that this discrepancy between the genders may be partly due to differences in alcohol consumption. Japanese men consume nearly four times as much alcohol as women, and that magnesium may counteract the oxidate stress of alcohol.
The investigators acknowledge that beneficial associations between magnesium intake and CRC risk may include the influence of other nutrients from foods, as participants with higher intakes of magnesium also tended to consume higher intakes of foods rich in calcium, zinc, fiber, folate, B-6 and vitamin D. Researchers conclude by stating “Increased intake of magnesium-rich foods is recommended if other studies, including randomized control trials, confirm our findings.”
The findings show a strong 52% reduction in colon cancer among men whose daily intake of magnesium was 327mg or greater, as opposed to the group whose intake was 238mg or less.
This was the latest of several studies suggesting a link between insufficient magnesium intake and colon cancer, including a Swedish study that showed magnesium reducing the chances of colon cancer in women. This study included supplements, and readers should note that Swedish women and Japanese women have very different genetic predispositions and diets.
Two things that are worth repeating here…
One is that increased consumption of magnesium rich foods almost guarantees that you will be getting more of all kinds of good nutrition. Again, foods that are high in magnesium tend to be very healthy and nutritious foods to begin with. So, by targeting more magnesium in your diet, you are in fact improving your diet in countless ways that you do not even know of.
The second point is the relation between alcohol and magnesium. While not mentioned by the doctors in the study above, alcohol consumption is know to decrease the magnesium levels in your cells. Obviously, eating a magnesium rich diet would help to counteract this. This may have also played a role in the Japanese study, as Japanese men do tend to drink much more than Japanese women (though many Japanese women are surprisingly strong drinkers as well).
Keep this in mind if you drink more than you should, and at least try to balance it out with a healthy diet of foods high in magnesium.