Alzheimer's and Aluminum: Canning the Myth In talking they forget the common appellation of things, and the names of persons, even of those who are their nearest friends and relations. For the same reason they never can amuse themselves with reading, because their memory will not serve to carry them from the beginning of a sentence to the end ... They were the most mortifying sight I ever beheld. --Jonathan Swift, Gulliver's Travels, 1726 Written more than 250 years ago, Jonathan Swift's words have echoed through time, capturing the same modern-day image of people robbed of their ability to think or remember, people who would today probably be diagnosed as having Alzheimer's disease (AD). Back in Swift's day, there was yet no name for the mysterious illness, no known cause and no cure. But in the two centuries since then, scientists have made considerable progress in understanding AD and researching its possible causes. Since the mid-1970s when studies first emerged suggesting aluminum as a possible factor in developing Alzheimer's, the public has been besieged by conflicting reports both supporting and refuting those claims. The fact is humans are constantly exposed to aluminum, which is the third most abundant element on earth and is ubiquitous in food, water and air. Could it be possible then that every potential exposure to aluminum -- whether consuming foods and beverages from aluminum cans, cooking with aluminum pots and pans, wrapping food in aluminum foil, using baking powder, toothpaste, antiperspirants or antacids which contain aluminum salts or compounds -- increases our chances of getting Alzheimer's? No Solid Link According to a panel of scientific experts who convened recently at a symposium sponsored by the International Life Sciences Institute (ILSI), the answer is decidedly "NO!" "This worry of the general public about aluminum is part of a general concern about the toxicity of our environment," said John Trevor Hughes, D.Phil., M.D., a fellow of Green College at the University of Oxford and international expert on aluminum toxicity. Hughes suggested that news coverage on the issue has overblown the facts. "My opinion is that the total evidence relating aluminum with dementia and in particular with AD is quite unconvincing." Zaven S. Khachaturian, Ph.D., associate director of neuroscience and neuropsychology at the National Institute on Aging, agreed: "Epidemiological studies especially with respect to aluminum as a causal factor are not convincing." At present, "We don't know of any risk factors." Yet from a public perspective, Alzheimer's is among the most-feared conditions of aging, eroding one's ability to think, remember, feel and speak. The disease progresses slowly over a period of eight to 20 years, until finally total care is necessary until death. AD is considered the most common cause of dementia among older people, currently affecting some four million Americans. An estimated $90 billion is spent annually on health care for AD patients. The risk of getting AD seems to increase with age, with three-fourths of all cases appearing after age 65. With the changing U.S. demographics, it is estimated that the number of people with the condition will rise to 14 to 17 million by the middle of the next century. Why Aluminum? Aluminum came to the forefront as a possible cause of AD about 20 years ago when researchers found what they believed to be significant amounts of aluminum in the brain tissue of Alzheimer's patients. Subsequent international studies have shown possible links between dementias and the presence of aluminum in drinking water or in the dialysis fluids used for patients with renal failure. Although aluminum also had been found in the brain tissue of people who did not have AD, recommendations to avoid sources of aluminum received widespread public attention. "Recommendations were made to avoid aluminum in the diet and to avoid aluminum products for cooking or storing foods," said Seymour G. Epstein, technical director at the Aluminum Association in Washington, D.C. "These claims and 'medical recommendations' did not come from the scientific or medical communities but were loosely based on results of a few scientific studies then in progress." While some scientists are now examining a genetic link to Alzheimer's (see sidebar), others have not completely abandoned the aluminum theory. Donald R. McLachlan, M.D., director of the University of Toronto's Centre for Research in Neurodegenerative Diseases, concludes in the book Alzheimer's Disease and the Environment, "There is no evidence for, or against, aluminum as a primary cause for AD. However, strong evidence from four independent lines of investigation support the idea that aluminum is an important factor in at least the dementia component of the Alzheimer degenerative process." McLachlan recommends limiting dietary exposure to aluminum and conducting research on the potential risk of aluminum exposure to human health. John Savory, Ph.D., professor of pathology and biochemistry at the University of Virginia in Charlottes-ville, who spoke at the ILSI symposium, concurred with McLachlan that aluminum "probably is involved to some extent, but there's still a lot of work to be done." However, Savory was in consensus with all symposium speakers that aluminum poses no threat to most humans. "In normal healthy individuals, we have excellent barriers against aluminum entering the body," Savory said. Physiologically, aluminum is poorly absorbed by the body and is usually excreted quickly following ingestion. H3>Breaking the Myth Early studies on brain/nerve damage due to aluminum exposure involved extremely high levels of aluminum, usually in a form to which most people would never be exposed, e.g., injected into the brain, inhaled industrial aluminum "dust," or dialysis fluid used for persons with kidney disease. According to Hughes, symptoms resulting from these unusual routes of exposure would be observed with any metal. Furthermore, such symptoms differ clinically and pathologically from those of AD. "Unlike many injurious metals, such as lead, mercury and tin, aluminum toxicity has been proven only rarely," Hughes said. Susie Humphreys, Ph.D., of the Food and Drug Administration's Center for Food Safety and Applied Nutrition concurred: "We do know that aluminum in the brain can be neurotoxic," however, "aluminum cannot cause all that has been attributed to it." According to Humphreys, antacids are the largest carrier of aluminum of any drug. One antacid tablet alone can contain 50 milligrams (mg) or more of aluminum, 10 times the amount recommended by McLachlan for daily human consumption. People using antacids for upset stomachs or peptic ulcers may consume more than 1,000 mg per day (more than 300 percent over McLachlan's recommendation) over several days. Yet, there's no evidence that the widespread use of these aluminum-containing drugs causes dementia. The same holds true for any other type of ingested aluminum from sources such as foods cooked in aluminum cookware and baked goods containing baking powder. The aluminum content from such dietary exposures are also significantly less than that in antacids. Other instances of exposure that have shown no aluminum toxicity, said Hughes, include topical treatments such as antiperspirants or antiseptic aluminum solutions used by doctors. Summing Up the Evidence While scientists continue to search for causes and cures of Alzheimer's, there does not appear strong scientific basis for a role involving aluminum. The Alzheimer's Association, the major nonprofit organization dedicated to dealing with the devastating disease, also has concluded that there is no scientific evidence proving aluminum plays a causal role in Alzheimer's disease. Until there is more conclusive evidence to the contrary, the Association does not recommend the public take any extraordinary steps to avoid aluminum. Why then, if the majority of scientific evidence seems to support the conclusion that aluminum plays no role in developing Alzheimer's, does the issue continue to be debated? Epstein concluded, "It's always harder to prove a negative." To learn more about Alzheimer's disease, contact: Alzheimer's Association 919 North Michigan Avenue Suite 1000 Chicago, IL 60611 (800) 272-3900 Alzheimer's Disease Education and Referral Center P.O. Box 8250 Silver Spring, MD 20907-8250 (800) 438-4380 Reprinted from Food Insight September/October 1993

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