This is how smoking changes the brain

A breakthrough pill hoped to help thousands of people give up smoking is due to be rolled out on the NHS in the UK.

Varenicline – made by pharmaceutical company Teva UK – is a once-a-day pill which works by tackling nicotine cravings and is thought to help with withdrawal symptoms such as irritability and trouble sleeping.

NHS England claims that when it is used in conjunction with behavioural support, it can help about one in four people stop smoking for at least six months.

Officials estimate it could help more than 85,000 people give up smoking annually over the next five years, as well as prevent up to 9,500 smoking-related deaths.

The addictive quality of nicotine is well-cited as one of the pivotal reasons why cigarettes are so hard to give up – but what other impacts does smoking have on our brains?

Reduces brain volume

Some research suggests that smoking cigarettes can impact the volume of crucial parts of our brain.

"Smoking can reduce brain volume," says Dr Steven Allder, consultant neurologist at Re:Cognition Health. "Studies show that smoking leads to brain atrophy, especially in areas critical for memory, learning and decision-making, such as the hippocampus and frontal cortex."

The toxic chemicals in cigarettes, such as nicotine and carbon monoxide, also restrict blood flow to the brain therefore reduce oxygen supply to brain cells, explains the neurologist.

"Over time, this contributes to cell damage and death, shrinking brain volume," forewarns Allder. "Additionally, smoking increases oxidative stress and inflammation, both of which can accelerate the breakdown of brain tissue, leading to a smaller, less dense brain structure."

Accelerates brain ageing

Chain smoking can have a big impact on many of our brain’s cognitive functions.

"Smoking accelerates brain ageing by damaging blood vessels and increasing oxidative stress," explains Allder. "It exposes the brain to free radicals, which harms neurons and causes inflammation, speeding up the ageing process.

"This leads to a faster decline in cognitive functions such as memory, processing speed and executive functions."

In addition, nicotine restricts blood flow, depriving brain cells of oxygen which exacerbates cell degeneration, adds the neurologist.

"Over time, these effects accumulate, causing the brain to age more rapidly than it would in a non-smoker, increasing susceptibility to age-related cognitive decline," highlights Allder.

Increased risk of neurodegenerative diseases

Many studies indicate that smokers are more at risk of developing a neurodegenerative disease such as Alzheimer’s.

"Smoking increases the risk of neurodegenerative diseases, such as Alzheimer’s and Parkinson’s," states Allder. "Smoking accelerates oxidative stress and inflammation, which damage brain cells and promote the formation of amyloid plaque formation, which is associated with Alzheimer’s.

"Reduced blood flow caused by nicotine constriction also increases stroke risk, which can lead to vascular dementia."

Some research also suggests that smoking may disrupt dopamine pathways, raising susceptibility to Parkinson’s disease, adds Allder.

"Smoking has also been linked to higher levels of brain toxins that impair cognitive function," notes Allder. "The cumulative effects of smoking make the brain more vulnerable to conditions that cause cognitive impairment and memory loss."

If you have been affected by issues raised in this story, please visit: www.rte.ie/helplines.