Smoking, COPD, and Neurodegenerative diseases: A triple threat

Smoking is widely known for its harmful effects on the lungs, but its effects go far beyond respiratory health. Smoking is associated with chronic obstructive pulmonary disease (COPD) and plays an important role in the pathogenesis and progression of neurodegenerative diseases. Together, these diseases pose a significant treat putting both physical and cognitive health at severe risk.
Chronic obstructive pulmonary disease (COPD)
Chronic obstructive pulmonary disease (COPD) is a chronic respiratory illness that ranks among the primary causes of morbidity and death globally. It is distinguished by chronic respiratory symptoms and decreased airflow and is an independent risk factor for cognitive impairment.
Smoking has been identified as the major cause of COPD, since long-term exposure to cigarette smoke eventually leads to COPD. According to studies, 80-90% of COPD patients had a history of smoking, with half of smokers developing COPD. Smoking causes significant stress on the lungs, limiting oxygen flow to the rest of the body, including the brain.
Neurodegenerative Diseases
Neurological diseases such as Alzheimer’s disease and Parkinson’s disease and others are responsible for progressive loss of nerve cells in the brain and spinal cord. Smoking has long been associated with an increased risk of these diseases. Toxic chemicals such as nicotine and carbon monoxide in cigarette smoke can cause oxidative stress and inflammation, both of which cause damage to brain cells
Studies have shown that smokers are at a higher risk of cognitive decline, and the damage caused by smoking is often greater in individuals with genetic predispositions such as Alzheimer's or Parkinson's Nicotine addiction for the condition is more difficult, as it can interfere with normal brain function

Studies have found that smoking shrinks the brain. The good news is that quitting smoking prevents additional brain tissue loss; but, ceasing smoking does not restore the brain to its previous size. As people's brains gradually lose volume with age, smoking effectively causes the brain to age prematurely,
Combination: COPD and Neurodegeneration
The relationship between COPD and neurodegenerative diseases is of particular concern. Both have similar risk factors, with smoking being the most prominent. In addition, reduced oxygen saturation due to COPD can exacerbate cognitive dysfunction. When the lungs are damaged, less oxygen gets to the brain, which impairs cognitive function and accelerates the progression of neurodegenerative diseases
Furthermore, the chronic inflammation seen in COPD is not restricted to the lungs. Inflammation in the body, including the brain, is associated with various neurodegenerative diseases. This means that someone with COPD may already be at high risk for cognitive decline, especially if they smoke. The dual burden of COPD and neurodegenerative diseases can significantly reduce quality of life, with patients frequently experiencing not only respiratory difficulties but also cognitive impairments affecting memory, decision-making and physical fitness
Breaking the wheel
While you can't undo the damage that has already been done, but you can avoid causing more damage. Smoking is a modifiable risk factor. The good news is, when you quit smoking, you allow your body to heal thereby reducing the inflammation, slowing the progression of COPD and avoid aging your brain and bringing down your chances of dementia.
(Dr. Praveen Gupta, Principal Director & Chief of Neurology, Fortis Hospital)