Does nicotine lower the IQ or harms the brain anyhow?

Nicotine is a substance that has been extensively studied and proven to harm brain health, especially when used over a long period or during adolescence. Although it can temporarily enhance attention and memory, this comes at the expense of long-term cognitive decline.
⏳ The Paradox of Short-Term "Brain-Boosting" and Long-Term "Brain-Damaging"
The impact of nicotine on the brain presents a clear short-term and long-term paradox.
Short-term effect (false "alertness"): Nicotine can rapidly (within about 10 seconds) pass through the blood-brain barrier and bind to the nAChRs (nicotinic acetylcholine receptors) in the brain, releasing neurotransmitters such as dopamine. This process brings about a brief sense of euphoria, relaxation, and a slight improvement in attention and memory. However, this improvement fades as nicotine is metabolized (within about 1-2 hours), leading to a craving that drives repeated use.
Long-term effects (real damage): Prolonged use of nicotine causes the brain to undergo neural adaptation, leading to a decline in cognitive function. Studies have found that the intelligence quotient of long-term smokers is 10.6% lower than that of non-smokers, and the rate of brain atrophy for long-term smokers is three times that of non-smokers. Even intermittent smoking can damage the hippocampus, which is responsible for memory. The impact varies across different age groups:
Crowd Long-term impact
Teenagers Their brains are particularly vulnerable, leading to learning and attention disorders, and the risk of addiction is extremely high.
Adults Long-term use is clearly associated with cognitive dysfunction (such as impaired working memory and attention), and accelerates brain aging.
Pregnancy/Fetus Nicotine is a neurodevelopmental toxin that can cause fetal hypoxia, resulting in weakened fetal lung function, auditory processing defects, and cognitive and behavioral deficits after birth.
⚠️ Mechanism of nicotine's damage to the brain
Nicotine causes physical damage to the brain structure and function through multiple pathways:
Brain structure damage: Research has found that repeated exposure to high doses of nicotine can cause atrophy of the gray matter in the prefrontal cortex of teenagers. Nicotine can also alter the connectivity of the brain, especially in the prefrontal cortex region involved in impulse control and decision-making. It can "reconnect" the circuits of the teenager's brain and disrupt the connections that control learning and attention.
Disorder of the neurotransmitter system: Nicotine-induced neurotoxicity may lead to changes in the dopamine system function and cerebrovascular dysfunction, thereby impairing cognitive function.
Cell damage and oxidative stress: Nicotine has been proven to cause oxidative stress and inflammatory responses in brain tissue, and even cause DNA damage.
Cerebral vascular damage: By causing atherosclerosis, nicotine reduces the blood supply and oxygen to the brain, which is a major cause of cerebrovascular diseases such as stroke and vascular dementia. In the long term, nicotine may also disrupt the communication of the "lung-brain axis" in the brain, thereby disrupting the iron balance and increasing the risk of dementia.
?? Nicotine and Specific Neuro-psychiatric Disorders
The effects of nicotine are particularly complex in individuals who already have neuro-psychiatric disorders.
Children/Alzheimer's Disease: Some studies suggest that medicinal nicotine may be harmful to children's neural development and might even trigger the neuro-pathological processes of Alzheimer's disease.
People with mental disorders: Although some studies have observed that patients with severe mental disorders such as schizophrenia have a high rate of smoking, large-scale and high-quality research has clearly indicated that smoking can significantly impair the cognitive functions of this group. They may use smoking as a form of self-treatment to alleviate certain symptoms, but this comes at the cost of sacrificing overall cognitive health.
❓ Common Myth Resolution: Does Smoking Really "Make People Smarter"?
This is a widely spread misconception. The stimulating effect of nicotine can give people the illusion of enhanced cognition, but this is a typical case of self-deception.
Scientific research has not found that long-term use can enhance intelligence. On the contrary, a number of high-quality studies have provided conclusive evidence to the contrary:
Intelligence quotient data: In a study involving tens of thousands of Israeli young people, the average IQ of smokers (approximately 94) was more than 7 points lower than that of non-smokers (approximately 101); those who smoked more than one pack per day had an even lower average IQ (approximately 90).
Cognitive efficiency: The overall cognitive efficiency (including information processing and reaction speed) of long-term smokers is 10.6% lower than that of non-smokers.
The downward trend in consensus: The claim that nicotine can "boost brain function" is unfounded. Currently, there are no research conclusions indicating that nicotine or related smoking cessation drugs can enhance brain function.
?? Summary
In conclusion, nicotine is a highly addictive neurotoxin. Its risks to the brain far outweigh any minor short-term benefits. To protect brain health, the best choice is to stay away from all tobacco and nicotine products, especially for teenagers during the critical period of brain development and for women who are planning to conceive or are pregnant.