Aluminum cookware is a long-standing kitchen staple due to its low cost and ability to effectively conduct heat. But decades ago, as autopsy reports found unusually high levels of aluminum in the brains of people with Alzheimer's disease, concern arose over the health risks of this metal -- including the safety of cooking foods in aluminum cookware. The U.S. Food and Drug Administration (FDA) reports the amount of aluminum that leaches into food from this cookware is much less than the amount naturally present in foods and other consumer products. But because aluminum is a known toxin to the body, the safety of dietary aluminum and this cookware is still a controversial issue with consumers.
Beyond cookware, aluminum is naturally found in rocks, minerals, clay and soil -- which is how it ends up in the plants we eat. It is also added to many processed foods. The Centers for Disease Control and Prevention (CDC) estimates the average adult consumes 7 to 9 mg of aluminum daily from foods, not including the amount that can leach into food by cooking with aluminum pots or pans. In addition, aluminum is added to many consumer goods, including some antacids, buffered aspirin, toothpaste, nasal spray and some cosmetics. As much as 100 to 200 mg aluminum is found in some antacid tablets, for example. In other words, it's nearly impossible to avoid aluminum.
Leaching From Cookware
The amount of this metal that leaches into food from aluminum cookware and utensils depends on a variety of factors. Acidic foods, such as tomato sauce, cause more aluminum to leach from this cookware compared to the effects of lower-acid foods, such as chicken or meat. Prolonged food contact with this metal -- such as longer cooking or storage times -- also increases the amount that seeps into the food. In addition, a July 2013 study published in "ISRN Public Health" found that older aluminum pots leach more of this metal into foods compared to new pots and utensils. A study published in the September 1985 issue of "Journal of Food Protection" estimated food contact with aluminum pans or foil can add an average of 3.5 mg aluminum to the daily diet, an amount the study authors considered insufficient to constitute a health hazard.
The body derives no benefits from aluminum, which can be inhaled, ingested or absorbed through the skin. This metal can cause lung damage if large amounts are inhaled, and is considered a neurotoxin, or a poison to the brain and nervous system. However, aluminum is very poorly absorbed, making oral intake from cookware or foods less concerning, according to the CDC. A report published in the February 2001 issue of "Regulatory Toxicology and Pharmacology" notes that less than 1 percent of ingested aluminum gets into the blood, most of which is excreted in the urine. However, people with severe kidney disease can retain higher amounts of aluminum in their bodies, which can lead to dementia, anemia or bone disease.
Aluminum and Alzheimer's Disease
In the 1960's, when aluminum was initially suspected to be a causative agent in Alzheimer's disease, concerns arose about the safety of using aluminum cookware. While this safety issue has not been fully resolved, dietary aluminum is no longer a major suspect in this disease. A report published in the May 2014 "Journal of Occupational and Environmental Medicine" noted, for example, that brain changes caused by aluminum toxicity are not the same as the damage or impairment noted in Alzheimer's disease. Also, conflicting research exists on key issues such as cognitive impact of occupational exposure and reliability of animal studies completed on aluminum toxicity.
While aluminum cookware may not pose health concerns, it's probably best to stick with cooking low-acid foods in these pots and pans, and not to store foods in aluminum containers. Anodized aluminum may be a better option. Anodization is processed that hardens the cookware surface, sealing the surface to prevent the leaching of aluminum into food. Care should also be taken to discard aluminum ware that is damaged in any way, which can happen even with the anodized version. Other cookware options include glass, stainless steel, modern enamel and cast-iron. If you have kidney disease, you are at greater risk for aluminum toxicity, so discuss ways to avoid excess aluminum with your doctor.
- Regulatory Toxicology and Pharmacology: Safety Evaluation of Dietary Aluminum.
- Agency for Toxic Substances and Disease Registry: Center for Disease Control and Prevention: Public Health Statement for Aluminum
- Journal of Occupational and Environmental Medicine: Is the Aluminum Hypothesis Dead?
- ISRN Public Health: Comparative Study of Leaching of Aluminium from Aluminium, Clay, Stainless Steel, and Steel Cooking Pots
- Journal of Food Protection: Aluminum Levels in Foods Cooked and Stored in Aluminum Pans, Trays and Foil.