I don't care for the idea, but I haven't seen any scientific research suggesting that anodized aluminum cookware specifically is harmful. Anodization subjects the surface of aluminum pots and pans to a process that builds up the metal's natural coating of oxide. This should yield a hard, nonreactive substance that forms a tough coating. As a result, an anodized aluminum cooking surface is non-stick, scratch-resistant and easy to clean. According to manufacturers, anodization seals aluminum so that the metal cannot leach into food. Anodized aluminum shouldn't react to acidic foods, so you can theoretically use these pots and pans for preparing rhubarb and sauces with tomato, wine or lemon juice - ingredients that you shouldn't cook in traditional aluminum pots.
Concerns about the safety of anodized aluminum stem from the supposed connection between aluminum and Alzheimer's disease. Some years ago postmortem examinations of the brains of patients who had the disease found traces of aluminum. Since then, study results have been contradictory. Some showed that high exposure to aluminum did not increase the risk of Alzheimer's while some found what appeared to be a connection. Today, researchers are looking elsewhere for the primary causes of the disease.
I generally advise against allowing food to contact aluminum during cooking. Aside from any concern about Alzheimer's, evidence suggests that ingesting aluminum can be harmful to the kidneys and may weaken bones by depleting the body of phosphorus and calcium. Quality aluminum cookware has a cooking surface of stainless steel or some other material - the aluminum is used only on the exterior surface for its superior heat-conducting property. (A rolled edge that allows food to touch only stainless is ideal). Well-made anodized aluminum cookware that doesn't have any scratches is probably okay as well, but if you cook in ordinary aluminum pots and pans (or anodized cookware with scratches) acidic liquids such as tomato sauce will react with the metal, which will get into food and then into your body.
Aluminum is all around us. It is the most abundant metal in the Earth's crust and is widely distributed in soil, plants and water, including our food and drinking water. But there is no need for aluminum in human nutrition, and because it is so chemically reactive, it is probably not good for us. Individuals with the highest exposures to aluminum are those who take aluminum-containing antacids daily or several times a week. The average human intake is relatively low; between 30 and 50 mg per day. It's estimated we absorb less than one percent of the aluminum we swallow.
Andrew Weil, M.D.