Doctor’s Tip: Metals are essential in trace amounts
This is another column in a series about Alzheimer’s disease, based on “Power Foods For The Brain” by Neal Barnard, M.D. As Dr. Barnard points out, we need “copper for building enzymes, iron for blood cells, and zinc for nerve transmission, among other functions.” But we only need trace amounts of these metals, which can easily be obtained from the food we eat.
According to evidence cited by Dr. Barnard, all three of these metals are found in the plaques and tangles found in the brains of Alzheimer’s patients. This doesn’t prove that these metals cause Alzheimer’s, but it does suggest that they may contribute. Let’s look at each one of these metals:
The recommended daily allowance of copper is 0.9 mg., and healthful sources include beans, greens, nuts, whole grains and mushrooms. Copper is an unstable metal — when a new penny or copper cookware darkens, oxidation and free radicals are occurring. When copper in our bodies oxidizes, brain health is compromised. Several studies show that people with high blood copper levels have more cognitive decline, especially in the setting of high intake of animal products (plants have properties that dampen the harmful effects of excess metals and other toxins). In a study of over 9,000 people in Chicago, the combination of high copper levels and high intake of trans and saturated fat, found in animal products and snack food, was associated with “a loss of mental function that was the equivalent of an extra nineteen years of aging.”
We know that the ApoE4 gene increases the risk of Alzheimer’s, and it turns out that people with this gene fail to make proteins that bind copper and “keep it out of harm’s way.” Excess copper comes from copper pipes, copper cookware, many vitamin/mineral preparations, and from eating at the top of the food chain. For example copper is ingested by farm animals and is stored in their muscle and fat, so when we eat meat we get a much higher dose of copper than if we just ate plants.
Iron is also an unstable metal, which rusts after contact with water — a process that involves harmful oxidation and free radicals. The RDA is 8 mg. a day for adult men and postmenopausal women, and 18 mg. a day for menstruating women. Healthful sources include greens, beans, whole grains and dried fruits. Anemia (low red blood count) and high red blood counts are both associated with cognitive decline. Plants contain what’s called non-heme iron, and our bodies are able to control the absorption of this type of iron, depending on whether we need more iron or not. Animals however, have heme iron, which we absorb even if we already have plenty. Another source of high iron levels are iron skillets and pans. And iron is in many vitamin/mineral preparations and breakfast cereals.
The RDA of zinc is 11 mg. per day for men and 8 mg. for women. Healthful sources include oatmeal, whole-grain bread, brown rice, peanuts, beans, nuts, peas and sesame seeds. Zinc is a stable metal, but according to Dr. Barnard it “seems to encourage beta-amyloid proteins to clump together to form plaques.” Many plants have something called phytic acid, that limits zinc (and copper) absorption. Zinc is added to many vitamin/mineral preparations, as well as breakfast cereals. And once again, you get more zinc if you eat at the top of the food chain.
Our bodies do not need aluminum. The link between this metal and Alzheimer’s is more controversial than the other metals listed above. Until we know for sure, Dr. Barnard recommends avoiding aluminum. Sources include baking powder, many antacids, single-serve creamers and salt packets, pickle relish, aluminum cookware, aluminum foil (especially used with acidic food such as tomatoes), and antiperspirants (most deodorants are fine).
Mercury can clearly harm the brain. Pregnant women and children are advised to avoid tuna and certain other fish because of mercury. But mercury is bad for the rest of us as well, and most fish contain it these days. There are some researchers who think mercury amalgam fillings are problematic, others who discount this. Dr. Bernard feels that since we don’t know for sure, it’s wise to replace mercury fillings with safer compounds.
Dr. Feinsinger, who retired from Glenwood Medical Associates after 42 years as a family physician, has a nonprofit Center For Prevention and Treatment of Disease Through Nutrition. He is available for free consultations about heart attack prevention and other medical issues, and to help people with hospital or other medical bills they don’t understand or think are too high. Call 970-379-5718 for an appointment. For questions about his columns, email him at firstname.lastname@example.org.
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