New brain imaging research has revealed for the first time that
people who only smoke cigarettes occasionally for social reasons
run a similar risk as regular smokers of reducing their grey
matter volume. The study was conducted by academics at the
University of Roehampton, the Combined Universities Brain Imaging
Centre, London, and King’s College London.
The research, which was first published in the academic journal
Addiction Biology*, shows that both regular and
intermittent smokers show a reduction in both volume and in
concentrations of important chemicals such as glutamate, in a
crucial area to the front of their brains, the prefrontal cortex.
Because this brain region is involved in complex thought
processes, emotional regulation and the inhibition of risky
behaviours, it is thought that tobacco smokers may be rendered
more impulsive and prone to risk taking than non-smokers. It is
believed that these changes in brain volume and function are
caused predominantly by the nicotine in tobacco, but may also be
due to the multitude of harmful chemicals that are also added to
cigarettes by manufacturers.
Eighty-five people in the UK, with an average age of 23 years
old, took part in the research, including 41 non-smokers, 24
intermittent smokers and 20 daily smokers. This is the first
study ever conducted which has examined both the effects of
intermittent and regular smoking on the brain. Participants were
examined using MRI brain scanners to compare brain capacity
differences between the three groups.
The daily smokers smoked on average 11.5 cigarettes every day for
at least one year, while the intermittent smokers smoked between
one to four cigarettes on at least one day per week. Of the 85
participants, 46 were male and 39 were female.
While the prevalence of daily smoking has decreased from 19.8% of
the population in 2011 to roughly 14.1% of the population today**
the proportion of cigarette users who smoke occasionally may be
increasing as the risks of regular smoking have been widely
publicised.
The research was led by Dr Paul Faulkner, Senior Lecturer, and
Professor Paul Allen, both from the Department
of Psychology at the University of Roehampton. Commenting on
the findings, they said: “Cigarette smoking is still the largest
contributor to disease and death worldwide. The findings of our
research confirms for the first time that both regular and
occasional smoking are associated with low volume and low
concentrations of important chemicals in the front part of the
brain; this may reflect the negative effects of nicotine on the
human brain, but may also make them more addicted to smoking,
thus creating a vicious circle.
“Intermittent smokers may think that that the risk to their
health is lower than regular smokers, but when it comes to the
negative effects on the brain, occasional, non-daily smoking has
a very similar impact as daily cigarette use.”
*A copy of the research paper is available to download here.
**Public Health England 2019
