Having trace amounts of molybdenum in our bloodstreams is not only normal but beneficial. The element piggybacks onto bacteria to help us metabolize proteins and grow new cells, and also helps keep our vertebrae and tooth enamel strong. But too much of it can indeed be toxic.
Health care practitioners worry more about miners exposed to molybdenum dust on a daily basis than they do about everyday folks with occasional and incidental exposure via cookware and ingested foods. Few if any cases of acute toxicity in humans have been documented, though animal studies have shown that ingesting small but frequent amounts can lead to diarrhea, growth retardation, infertility, low birth weight and even gout. It has also been shown to negatively affect the lungs, kidneys and liver.
But most of us need not fear, as the amount of molybdenum we get naturally from eating foods like green beans, eggs, sunflower seeds, wheat flour, lentils and cereal grain is not enough to cause any severe health reactions, and, again, is an important building block component of our diets. In fact, a deficiency of molybdenum in one stretch of northern China—where the element does not occur naturally in the region’s soils—has been linked to a higher-than-normal rate of esophageal cancer.
Additional amounts of molybdenum could be getting into your foods from stainless steel cookware, but manufacturers insist that if their products are not dinged and pocked from overuse or abused with abrasive brushes or detergents during clean-up they shouldn’t leach much of anything into the food cooking inside.
Of all the elements used to make stainless steel, molybdenum is one of the most able to tolerate high heat without expanding, softening or otherwise breaking down. That’s largely why it is approved for use in food-grade products by the U.S. Food and Drug Administration. Incidentally, its heat tolerance is also why it is used in the making of missiles, aircraft, rifle barrels, light bulb filaments and furnace components.
While it is unlikely that the amount of molybdenum in a normal human diet is enough to cause severe health reactions, no one would fault someone with reason for concern to take precautions. For starters, if you do have too much molybdenum in your systems, add some tungsten (sodium tungstate) into your diet, which naturally reduces the concentration of molybdenum in human tissues.
With regard to cookware, switching away from stainless steel might be a good idea for anyone with high molybdenum levels in their bloodstreams. No cookware is perfect, but cast iron and anodized aluminum seem to be the top choices today for cooks concerned about leaching elements. While cast iron is known to leach some iron into food, iron deficiencies were far less common before World War II when most of our grandparents cooked with it. And anodized aluminum is an ideal non-stick, acid- and scratch- resistant surface which locks-in aluminum that could otherwise leach into food.
CONTACTS: International Molybdenum Association