MANY people have heard "somewhere" that a principal cause of Alzheimer's Disease is aluminium deposits in the brain, caused (so the logic they've "heard" goes) by eating meals made in aluminium saucepans. So is it true that non-stick pans are the way to avoid this progressive disease?

Unsurprisingly, it's not. The facts we do know about Alzheimer's Disease, which affects so many people including the former US president Ronald Reagan, are surprisingly few. It affects both men and women, it's not contagious, it's not caused by stress, but most importantly it is not part of "normal" aging. Alzheimer's is not inevitable as you get older.

The idea that aluminium might be involved in Alzheimer's emerged from studies in the 1960s, in which experimenters injected rats with aluminium compounds: they found this led to more "neurofibrillary tangles" in the brain - a corollary of Alzheimer's.

From there the leap of logic that "it must be caused by aluminium in our food" was unfortunately inevitable, even though it's not one that the scientists would have made: they would tell you that injecting rats doesn't tell you a lot about normal humans.

An idea about Alzheimer's that is currently in the ascendant is that it is distantly related to disorders like Creutzfeldt-Jakob Disease (CJD), reckoned to be due to the accumulation of malformed proteins made by the body. Alzheimer's patients show similar build-ups of "beta-amyloid plaques", which are deposits of the insoluble form of a protein made normally by the body. The plaques appear to interfere with brain function.

However, just as aluminium was receding over the horizon, newer research has come in suggesting that maybe it does have a role to play after all.

Several studies have reported that people who live in areas with low levels of aluminium in the drinking water have less chance of developing Alzheimer's Disease than those who live where levels of aluminium in the drinking water are higher. Cause and effect? Or just chance? Or was it actually not Alzheimer's at all, as has been suggested by others?

At present, the strongest signs are that Alzheimer's has a genetic element, predisposing you towards developing it, and that some environmental factors may play a part. But you can hang on to the old pots and pans.