Is there evidence that nicotine is toxic to the brain?
Literally speaking, nicotine is toxic to the brain in large enough quantities, meaning that it impairs brain function leading to serious illness or death. Nicotine overdoses are rare but have increased with the introduction of e-cigarettes, which can deliver more nicotine than traditional cigarettes.
Nicotine poses a series of other health risks, including cardiovascular, respiratory, gastrointestinal, immune and reproductive damage, addiction, and cancer. A 2012 study on the effect of nicotine on the adolescent brain found that “smoking increases the risk of developing psychiatric disorders and cognitive impairment in later life.”
The evidence that nicotine enhances brain function is mixed. A 2018 review of the literature found that nicotine improves motor function, attention and memory, but a 2020 review found results were inconsistent amid some evidence of tobacco industry funding.