Ian Graham, of Christchurch, asks :-

I have been told that I shouldn't use aluminium cooking pots because aluminium can contaminate the brain. Is this so?

John Reynolds, a neuroscientist at the University of Otago, responded.

This is a question which I remember concerned my parents in the 1970’s when this issue was first raised as a possibility in the media. My father even took the step at one stage of throwing away many of his aluminium pots out of concern.

Science has indeed since confirmed that aluminium, being a metal that the brain does not need for normal functioning, is toxic to brain cells but only when present in large concentrations. There is also evidence that aluminium can accumulate in the brain if ingested in sufficient quantities. After an unfortunate accident in Camelford in the United Kingdom in 1988 where aluminium at very high levels was accidentally pumped into the town water supply, a small number of people developed dementia-like brain disorders, three of whom died some years later with typically ten times the level of aluminium normally considered safe found in their brains after death.

However, the reality is that despite quite a bit of research, the jury is still out on whether sufficient amounts of aluminium could be ingested from pots or cans to cause any brain issues.

The particular concern has been a link with Alzheimer’s disease. Aluminium can interact with small fragments of proteins causing them to clump together and accumulate. These are the fragments which in sufficient quantities are known to lead to brain cell deterioration in Alzheimer’s disease. This does make a link between aluminium and Alzheimer’s disease likely, however it does not mean that the aluminium is the primary cause of Alzheimer’s.

Indeed, for every study that has found an association between aluminium and Alzheimer’s there is a study that has reported no significant levels of aluminium in Alzheimer’s brains. On balance, the Alzheimer’s society maintains that there is insufficient evidence to declare exposure to the typically low levels of aluminium that we might ingest through our diet, through aluminium cans or pots, or other products, as a causative agent for Alzheimer’s disease.