THE DETAILS: Copper and iron are both essential elements, required for our survival. Iron carries oxygen to red blood cells and to muscles, and helps produce important neurotransmitters in the brain; copper helps your body metabolize iron, boosts your immune system, and keeps your nerves and blood vessels healthy. And while most health officials are aware that people can experience deficiencies in both—iron-deficiency anemia being an example most of us have heard of—very little attention is paid to the damage caused by getting too much of either mineral.
In his paper for Chemical Research in Toxicology, George Brewer, MD, professor emeritus of internal medicine and human genetics at the University of Michigan Medical School, examined the available research on copper and iron toxicity and writes that what little research has been done has linked them to Alzheimer's disease, heart disease, diabetes, Parkinson's disease, and a few other neurological disorders. He refers to one study in which Italian researchers found elevated levels of copper in the blood of Alzheimer's patients. In another study, researchers analyzed copper levels in the blood of a large sample of healthy adults over a six-year period, and those with the highest levels of copper lost cognition three times faster than adults with normal copper levels. Iron is suspected of causing similar damage, he writes, because both metals can introduce too much oxygen to the brain, causing "oxidative stress" that damages neurons. Finally, because both are attracted to fat and cholesterol, Dr. Brewer points out that their ability to oxidize LDL cholesterol leads to the buildup of plaque on artery walls, contributing to atherosclerosis, an early form of heart disease characterized by the hardening of arteries.
Read on to find out who should worry about their copper levels.
WHAT IT MEANS: What's interesting about these metals, Dr. Brewer says, is that they only seem to be toxic in high quantities once you pass your reproductive years, usually around age 50. "These metals are good when you're younger because you need them for reproduction," he says, adding that younger bodies are also better able to defend themselves against excess levels. It's in our later years that most of the damage occurs. For one, women stop menstruating, which is one way the body keeps iron levels in check, he says, and iron begins to build up in the body. And in both women and men, age weakens the mechanisms that fight oxidative stress, he says, which damages the brain. "One main thing that happens is that the blood-brain barrier, which normally protects against these toxic molecules, becomes more leaky, and it becomes easier for copper and iron to infiltrate the brain."
If you're over 50, cutting excess copper and iron out of your diet is generally easy, and can be accomplished with some water filters and a little label reading:
• Get your levels checked. Regardless of your age, don't go on any low-copper or low-iron diet before getting your levels checked by a physician. While too much can be damaging, too little of either can lead to anemia, which itself can trigger heart attacks.
• Read your multivitamin label. Dr. Brewer says that multivitamins are the primary source of excess copper in our diets. Most supplements contain 2 milligrams (mg) of copper, which is more than the 0.75 mg that we need to survive, he says, and most people get at least 1 mg of copper from the foods they eat. "Copper is essential to life, and the idea is to make those pills contain all the essential vitamins and minerals," he says, "but in this case, that's a serious mistake." He notes that in the study of adults and cognition, the adults with the highest levels of copper had them because they were taking multivitamin supplements. Find a brand that contains no copper, he advises.
• Buy a water filter. Eighty percent of homes in the U.S. have copper water pipes, and Dr. Brewer suspects that a good portion of our copper exposure is coming from them. "Copper leaches from these pipes in high enough amounts to be damaging, at least according to the animal studies," he says. According to the National Sanitation Foundation, carbon filters, reverse osmosis systems, and distillers will remove copper from your water, so be sure to buy a filter that's NSF-certified to do so. Copper cookware will also leach copper, he says, especially when it's new, but he doesn't have any information about the specific quantities.
• Eat less red meat. All meats and vegetables contain copper, Dr. Brewer says, but red meat contains forms of both copper and iron that are more easily absorbed by your body. Copper in vegetables, on the other hand, is bound to proteins and elements that prevent your body from absorbing it, so excess copper from plant sources is excreted more easily. Even if copper toxicity isn't an issue for you, making meat less prominent in your diet will benefit your health—and the environment—in other ways.
• Take more drastic measures. Dr. Brewer takes zinc to control copper levels in his blood, and he recommends giving blood once every two months to keep your iron levels in check. "But both should be done under the supervision of a doctor," he cautions, "because you don't want to become deficient." Know your copper levels before using these tactics for copper control.