New research finds that smoking may raise the risk of dementia by creating chemical signals that move from the lungs to the brain. Earlier ideas focused on damage to blood vessels and less oxygen in the brain, but the new study suggests nicotine can change organ communication.
Researchers found rare lung cells called pulmonary neuroendocrine cells (PNECs) release tiny particles called exosomes when exposed to nicotine. These exosomes contain serotransferrin, a protein that helps control iron. The team made similar lung cells from human stem cells so they could study many cells in the lab.
Changes in iron balance can affect brain cells and match markers seen in neurodegeneration. The vagus nerve could carry the lung signal to the brain. Scientists are testing whether blocking these exosomes could lead to future treatments, but effects on people are still years away.
Difficult words
- dementia — A loss of memory and thinking skills
- nicotine — A chemical in tobacco and cigarettes
- exosome — A tiny particle released by cellsexosomes
- serotransferrin — A protein that helps control body iron
- pulmonary — Related to the lungs and breathing
- vagus nerve — A nerve that connects the body to brain
- neurodegeneration — Progressive damage to brain cells and tissue
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Discussion questions
- Do you think smoking can harm the brain? Why?
- Would you try to stop smoking after reading this? Why or why not?
- What could scientists try to block to help people, according to the article?
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