Sunday, February 7, 2016
Coffee and Magnesium
On reaching the age of 65, I am looking at a number of nutritional requirements, including mineral balance. I read contradictory advice about the role of coffee and magnesium uptake. Nutritionally coffee looks perfect: lots of magnesium and low calcium/phosphorus (both of which are plentiful elsewhere in the diet). Yet some sites say coffee depletes magnesium reserves. I tend to believe coffee must be a significant magnesium contributor, especially with the recent `health` findings of coffee. What do you say?
I admire your commitment to staying healthy by reviewing your age appropriate dietary needs. Nutrient requirements often do change as we age and, as you note, research in nutrition often provides us with conflicting information. Magnesium and coffee's role is no exception. Until we have "proof positive" scientific data on their connection (positive or negative), I say that it is fine to consume coffee in moderation, as one source of magnesium.
However, there are better sources of magnesium you can enjoy too. You can find higher levels in vegetables and grains, and lesser amounts in fruit, milk and seeds/nuts. Some magnesium rich foods include spinach, greens, broccoli, lima beans, potatoes, squash, whole bran, wheat germ, whole-grain products, figs, peaches, bananas, berries, avocado. Also, milk, yogurt, tofu, nuts, shrimp, kidney beans, and sunflower seeds.
To give you a small comparison: One cup of coffee (8 oz.) provides about 7 milligrams (mg) of magnesium. One cup of spinach provides 157 mg., two tablespoons of peanut butter gives us 51 mg., and a banana, 34 mg. Obtaining adequate magnesium in the diet should not be a problem, unless you are on a medication that depletes it (such as a diuretic). Note: according to the Dietary Reference Intakes (DRIs) if you are age 51 and older, the average man needs 420 mg. of magnesium per day and the average woman 320 mg.
For more help with planning a diet adequate in nutrients for your gender, age, and activity level you may want to visit ChooseMyPlate.gov. Thanks for your question!
Jane Korsberg, MS, RD, LD
Senior Instructor of Nutrition
School of Medicine
Case Western Reserve University