That myth was started when it was discovered that unusually high deposits of aluminum were found in the brains of alzheimer's victims. But the very scientist who found that abnormality said that it was impossible for aluminum cookware to be the source. A lifetime of using it could not account for the amounts found.
That didn't stop the MSM and the healthnut wackos from spreading the BS causing people to toss millions of dollars worth of perfectly good cookware. Most aluminum cookware is cast aluminum which is too hard to easily leach into foods.
That was about 1979. Now aluminum is never mentioned.
The aluminum comes from under arm deorderant, that’s a well known fact.