With commentary by lead study author Daniel Dibaba, PhD Candidate
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 (T2D), which are risk factors for pancreatic cancer. In fact, between 65 to 80 percent of pancreatic cancer patients have some form of glucose intolerance, including prediabetes or T2D.1
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 cancer formation.
Findings of the VITamins and Lifestyle study,2 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 recommended dietary allowance (RDA) for magnesium had a lower risk of pancreatic cancer compared to those who did not meet the RDA for this mineral. More specifically, there was a 76 percent increase in the incidence of pancreatic cancer in those who took in less than the RDA for magnesium compared to those who met or exceeded the base level recommended.
For every 100 mg a day decrease in magnesium intake, it resulted in 24 percent increase in the 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 candidate, in the School of Public Health at Indiana University in Bloomington. This suggests that supplementation may be advised for individuals at risk to boost their magnesium levels to meet the RDA.
Prior study findings suggested that pancreatic tumor cells have receptors for insulin and contain high levels of insulin offering support for a likely association between magnesium Separately, there’s evidence that insulin-like growth factor (IGF) may play a role in pancreatic cancer.
The level of insulin-like growth factor seems to be higher in individuals who have glucose intolerance, insulin resistance, and high insulin levels. In addition, 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 same researchers looked at the association between dietary magnesium levels and a person's serum C-reactive protein (CRP) in five intervention studies.3 C-reactive protein is a clinical measure of inflammation, such as in heart disease. Since people with diabetes are at increased risk for cardiovascular disease, it is vitally important to pursue all means available to keep CRP levels low.
Diababa et al, reported an inverse association between the dietary intake of magnesium and serum CRP levels. In fact, their findings suggest a beneficial effect of magnesium intake on serum CRP levels.3
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 30.4
Good food sources of magnesium are green leafy vegetables, nuts, seeds, legumes, and whole grains. Some breakfast cereals and other foods may be fortified with magnesium. The best dietary sources include nuts and dark leafy greens, which contribute the highest levels of magnesium.
Depending on the food sources, reach the RDA for magnesium means about 5 to 8 servings of these foods daily, which is why supplementation may be necessary.
2. Dibaba D. Xun P, Yokota K, White E, He K. Magnesium intake and incidence of pancreatic cancer: the VITamins and Lifestyle study. British J Cancer. 2015;113:1615-1621.