Plastic water bottles expose the drinker to bisphenol-A (BPA), a form of estrogen that has been linked to problems in the human reproductive and immune systems. Aluminum does not contain BPA.
Link to Alzheimer's Disease
Some studies have shown that people with Alzheimer's disease have unusual amounts of aluminum in their brains. However, it is unclear whether high levels of aluminum cause Alzheimer's disease.
Effects on Nervous System
A 2008 study by the Agency for Toxic Substances and Disease Registry (ATSDR) tested animals after they received oral doses of aluminum in high amounts. The animals' motor skills showed signs of decline.
No Link to Cancer
Neither the Environmental Protection Agency nor the Department of Health and Human Services has studied the relationship between aluminum and cancer in humans, but no link has been found in tests conducted on animals.
Bone Development Risk
The ATSDR has found that aluminum can adversely effect bone development in young children. Children who were given aluminum in medical treatments for kidney problems developed diseases of the bone.