Magnesium intake may be an effective way to prevent pancreatic cancer, a new studies suggest.
Pancreatic cancer is the fourth leading cause of cancer-related death in both men and women in the United States. The overall occurrence of pancreatic cancer has not significantly changed since 2002, but the mortality rate has increased annually from 2002 to 2011, according to the National Cancer Institute.
“Pancreatic cancer is really unique and different from other cancers,” says Ka He, chair of the epidemiology and biostatistics department at Indiana University. “The five-year survival rate is really low, so that makes prevention and identifying risk factors or predictors associated with pancreatic cancer very important.”
Recent Study at Indiana University
Previous studies have found that magnesium is inversely associated with the risk of diabetes, which is a risk factor of pancreatic cancer. But few studies have explored the direct association of magnesium with pancreatic cancer and those that did had inconclusive findings, says lead author Daniel Dibaba, a PhD student in the School of Public Health.
Using information from the VITamins and Lifestyle study, the researchers analyzed an enormous trove of data on more than 66,000 men and women, ages 50 to 76, looking at the direct association between magnesium and pancreatic cancer and whether age, gender, body mass index, non-steroidal anti-inflammatory drugs use, and magnesium supplementation play a role.
Of those followed, 151 participants developed pancreatic cancer. Every 100-milligrams-per-day decrease in magnesium intake was associated with a 24 percent increase in the occurrence of pancreatic cancer.
The study, published in the British Journal of Cancer, also found that the effects of magnesium on pancreatic cancer did not appear to be modified by age, gender, body mass index, or non-steroidal anti-inflammatory drug use, but was limited to those taking magnesium supplements either from a multivitamin or individual supplement.
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.
“For those at a higher risk of pancreatic cancer, adding a magnesium supplement to their diet may prove beneficial in preventing this disease,” Dibaba says.
“While more study is needed, the general population should strive to get the daily recommendations of magnesium through diet, such as dark, leafy greens or nuts, to prevent any risk of pancreatic cancer.”
EPIC Cohort Study
Another recent study on magnesium for pancreatic cancer was the EPIC Cohort from Europe, which included 142,203 men and 334,999 women with an average 11.3 year follow-up. Stratified analysis showed that every 100 mg/day increase in dietary magnesium reduced the risk of pancreatic cancer by 21 percent for those with a BMI of 25 or greater.
Importantly, these results closely echoed the outcome of an earlier study from the UK (done on men only), which showed that men with the highest magnesium intakes (423 mg/day) had a 33 percent lower risk of pancreatic cancer than those with the lowest levels (281 mg/day). Again, this risk reduction was only valid and statistically significant for men with a BMI of 25 or greater. A 14 percent risk reduction was seen for the general male population (highest to lowest quintile of magnesium intakes) but the effect was not statistically significant.
Magnesium and Cancer
It shouldn't be surprising that magnesium plays a role in cancer. It takes part as a co-factor in over 300 enzyme systems and is found in every tissue of the human body. And relevant for cancer, it plays a critical function in DNA repair, cell differentiation, proliferation and angiogenesis. Magnesium deficiency has also been linked directly to inflammation and oxidative stress, and now, to increased cancer risk. Unfortunately, 79 percent of American adults don't get enough in their diets (given the current recommended daily dosage).
The RDA for magnesium is 420 mg for men and 310 mg for women up to age 30, and 320 mg for women over age 30.
Note that magnesium deficiency is more likely in seniors, heavy drinkers, and those with hyperglycemia, gluten sensitivity, and Crohn's disease.
There are no adverse effects of magnesium intake from foods, but supplements of all types may have some side effects. Some elderly patients who have impaired kidney function may suffer from toxic effects of magnesium-containing laxatives and antacids such as milk of magnesia. The Tolerable Upper Intake Levels (UL) for adults and adolescents over 9 years of age is 350 mg from nonfood sources of magnesium.
Calcium in the diet decreases absorption in the digestive tract; therefore, the use of calcium supplements can reduce the absorption of magnesium.
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.
Let’s review some of the magnesium-rich foods’ suggestions for your table.
Almonds (Magnesium: 105 mg in ¼ cup)
Other body benefits: Almonds are rich in vitamin E, an antioxidant that keeps the immune system strong and eyes healthy. They're also packed with protein, which helps fill you up and slim you down, as well as heart-healthy omega-3 fatty acids.
Best ways to eat them: Grab a handful for a satisfying snack or sprinkle them over a bed of greens for a more filling salad.
Sesame seeds (Magnesium: 101 mg in 1 ounce roasted)
Other body benefits: Sesame seeds may add some sizzle to your sex life — they're chock-full of zinc, which can help testosterone and sperm production in men. They're also a good source of iron and vitamin B-6.
Best ways to eat them: Mix them into granola or sprinkle them into a stir-fry.
Sunflower seeds (Magnesium: 128 mg in ¼ cup)
Other body benefits: Sunflower seeds are a surprisingly good source of bone-building calcium. Additionally, they're high in polyunsaturated fats, which can help reduce bad cholesterol levels in your blood when eaten in moderation.
Best ways to eat them: You can have them as a snack, but beware store-bought packages: most of them are loaded with sodium. Instead, buy raw sunflower seeds and toast them yourself.
Bananas (Magnesium: 33 mg in one medium banana)
Other body benefits: When bananas are still a little green, they are one of the best sources of resistant starch, a healthy carb that fills your belly and fires up your metabolism. Bananas also offer a dose of potassium, an electrolyte that can help lower blood pressure naturally.
Best ways to eat them: The options are practically endless: blend them into a smoothie, slice them into a bowl of oatmeal or onto a top of peanut-butter toast, or simply pull of the peel and take a bite.
Cashews (Magnesium: 89 mg in ¼ cup)
Other body benefits: A serving of cashews provides nearly 10 percent of your daily iron needs. The nuts are also a good source of folate and vitamin K.
Best ways to eat them: Have them on their own for a satisfying snack (just buy the unsalted kind). You could also toss them into a stir-fry or on top of a salad.
Tofu (Magnesium: 37 mg in ½ cup)
Other body benefits: This vegetarian soy protein source gives you 43% of your daily calcium needs in a ½-cup serving. You also get a dose of iron, a mineral the body needs to produce hemoglobin — the protein that helps red blood cells deliver oxygen throughout the body.
Best ways to eat it: Tofu takes on the flavor of whatever you cook it in. Try subbing it in for chicken or beef in your next stir fry. Extra firm tofu can also be put onto the grill.
Pumpkin seeds (Magnesium: 74 mg in 1 ounce)
Other body benefits: The seeds from your jack-o-lantern are a good source of fiber, with 5 grams per ounce. Pumpkin seeds also have plenty of heart-healthy monounsaturated fats, as well as 5 grams of protein per serving.
Best way to eat them: Fiber and protein make pumpkin seeds a slimming snack. Toast seeds in a skillet until golden brown and beginning to pop, about 4 minutes, and then transfer them to a baking sheet. Let cool completely, stirring occasionally. Pumpkin seeds also make a savory salad topper.
Flaxseed (Magnesium: 40 mg in 1 tablespoon whole)
Other body benefits: A sprinkling of ground flaxseed turns a cup of yogurt or cereal into a heart-healthy breakfast: a tablespoon contains more than half your recommended daily intake of omega-3 fatty acids. Flaxseed also gives you doses of fiber and the antioxidant lignan.
Best way to eat it: Flaxseed has a nutty flavor that works well sprinkled into yogurt and cereal, or blended into smoothies. Just be sure to grind them first (or buy them pre-ground) — otherwise the seeds will pass through you without being digested, and you won't reap the health benefits.
Milk (skim) (Magnesium: 27.8 mg in 1 cup)
Other body benefits: You've had the health benefits of milk drilled into your head since you were a kid, but here's a quick review: a cup of milk provides about a third of your daily recommended intake of calcium, which you need to build healthy bones and keep them strong as you age. Milk is also a good source of potassium, vitamin D, protein, and vitamin B-12.
Best way to eat it: Pour low-fat or fat-free milk over cereal, blend it with fruit and nut butter for a smoothie, or simply pour it into a glass and drink up.
Oatmeal (Magnesium: 57.6 mg in 1 cup cooked)
Other body benefits: This healthy whole grain fills you up with folate, fiber, and potassium. Plus, it can help lower cholesterol, and oats are even rich in omega-3 fatty acids.
Best way to eat it: Have it at breakfast with your choice of toppings. Just go easy on the sweetener.
Broccoli (Magnesium: 51 mg in ½ cup cooked)
Other body benefits: A serving of the cruciferous superfood contains more vitamin C than an orange. Plus, research shows that people who eat lots of broccoli may have a lower risk of certain types of cancer, including colon and bladder cancer.
Best way to eat it: You'll get the most nutritional bang for your buck if you eat broccoli raw or lightly steamed, and paired with tomatoes.
Sweet corn (Magnesium: 33 mg in 1 ear)
Other body benefits: Some people say carb-heavy corn is a diet no-no. Though corn does have 6 to 8 grams of naturally occurring sugar in one ear, this healthy whole grain is also a great source of fiber, B vitamins, vitamin C, and plant-based protein.
Best way to eat it: Go beyond cobs drenched in butter and salt. Instead, brush them with olive oil and place them directly on a hot grill for a smoky flavor.
Peas (Magnesium: 48 mg in 1 cup)
Other body benefits: A cup of peas provides nearly a day's worth of vitamin C. Peas also provide protein, potassium, and vitamin A.
Best way to eat them: The possibilities are endless: toss peas in a stir-fry or on top of a salad, make a belly-warming split-pea soup, mix them into pasta, or even eat them raw.
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