Magnesium May Reduce Risk of Pancreatic Cancer
With commentary by lead study author Daniel Dibaba, a PhD student in the School of Public Health, Indiana University in Bloomington.
Taking magnesium may reduce the risk of pancreatic cancer, one of the most deadly cancers, according to a new study. The mineral is known to reduce the risk of insulin resistance and type 2 diabetes, which are both risk factors for pancreatic cancer. In fact, between 65 to 80 percent of pancreatic cancer patients have some form of glucose intolerance, including prediabetes and type 2 diabetes. But until now, it was not known whether magnesium indirectly reduced the risk of pancreatic cancer (by reducing the risk of diabetes) or whether it had a direct impact on risk.
The new study, published in the British Journal of Cancer, looked at more than 66,000 patients in a health database from Washington State. Of those studied, 151 people developed pancreatic cancer. Researchers found that those who met the RDA for magnesium had a decreased risk of pancreatic cancer compared to those who did not meet the RDA. More specifically, there was a 76 percent increase in incidence of pancreatic cancer in those who took in less than 75 percent of the RDA for magnesium compared to those who met or exceeded the RDA.
For every 100 mg a day decrease in magnesium intake, it resulted in 24 percent increase in incidence of pancreatic cancer. However, when the researchers compared those who took a magnesium supplement with those who didn’t, the benefits disappeared in non-supplement takers.
“The strong effect was only observed in those taking both dietary and supplemental magnesium indicating supplementation was beneficial,” says the study author Daniel Dibaba, a PhD student in the School of Public Health, Indiana University in Bloomington. This suggests that supplementation may be needed to meet the RDA.
Studies suggest that pancreatic tumor cells have receptors for insulin and contain high levels of insulin, and there’s evidence that insulin-like growth factor (IGF) may play a role in pancreatic cancer. IGF levels are higher in those with glucose intolerance, insulin resistance and high insulin levels. Magnesium has been shown to improve insulin sensitivity, possibly reducing insulin and IGF.
Pancreatic cancer is the fourth most deadly cancer in the U.S. for both men and women. “For those at a higher risk of pancreatic cancer, adding a magnesium supplement to their diet may prove beneficial in preventing this disease,” Dibaba said. But magnesium may benefit everyone, not just those with insulin resistance or type 2 diabetes, though more research is needed.
The RDA for magnesium is 400 mg for men and 310 mg for women up to age 30, and 320 mg for women over age 30.
Good sources of magnesium are green leafy vegetables, nuts, seeds, legumes, and whole grains. Some breakfast cereals and other foods may be fortified with magnesium. Depending on the food, getting the RDA of magnesium means about 5 to 8 servings of these foods (nuts and dark leafy greens have the highest levels) a day, which is why supplementation may be necessary.