Experts have identified a new mechanism that explains how smoking may increase the risk of dementia, showing that the lungs have a direct role in brain health.
Previous studies have shown that heavy smoking in middle age is associated with more than doubling the risk of developing dementia, including Alzheimer's disease, decades later.
A new study from the University of Chicago suggests that nicotine may activate a previously unknown biological pathway that helps explain this link.
The researchers found that certain specialized cells in the lungs, called pulmonary neuroendocrine cells (PNECs), release tiny particles known as exosomes in response to nicotine. These exosomes interfere with how the brain regulates iron – a process essential for healthy nerve cell function.
Disturbance of this balance can damage neurons, cause stress on their energy systems, and contribute to processes associated with neurodegenerative diseases such as Parkinson's disease.
According to researchers, this discovery strengthens the idea of a "lung-brain axis", showing that the lungs are not only a victim of tobacco smoke, but also an active organ that affects brain function.
The study, published in Science Advances, is based on laboratory models and stem cell research. However, the scientists emphasize that further studies are needed to confirm this mechanism in humans.
The research team is also exploring the possibility of blocking these exosomes as a potential way to develop therapies that protect the brain from damage caused by smoking.
Meanwhile, smoking rates in the UK have fallen to record lows, but the pace of decline has slowed and in some areas is even increasing. The latest figures show that around 9.1% of adults smoked in 2024, while the use of e-cigarettes has increased significantly, especially among young people.
Authorities are trying to accelerate this progress through a new law on tobacco and electronic products, which aims to create a “smoke-free generation.” Under the proposal, people born after January 1, 2009, would never be legally allowed to purchase tobacco products.
The bill also includes stricter measures to control e-cigarettes, restricting advertising, flavors, and packaging.
Over 1,200 health professionals – including doctors and nurses – have supported these measures, considering them essential for reducing smoking and preventing nicotine addiction in younger generations. /GazetaExpress/
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