[esperent]

I'm gonna make a guess that it's the long debunked hypothesis that aluminum cookware and cans are linked to Alzheimers.

As it turned out, aluminum poisoning can cause dementia-like symptoms, but you can't get aluminum poisoning from cookware or cans.

[roncesvalles]

Many aluminum cans have residual aluminum shavings inside and outside. The manufacturing process isn't perfect.

I've personally noticed shavings multiple times on the lip (especially with cheaper non KO/PEP products). La Croix cans are notorious for this.

[theandrewbailey]

Aren't most food cans made of steel, not aluminum?

[ButlerianJihad]

Food and beverage cans are made of plastics with a metallic wrapper. Don't worry -- I'm sure it's BPA-free!