Scientists think they know why women find it harder to quit smoking than men

Woman smoking
Researchers may have discovered why women can find it harder to quit smoking than men. (Getty Images) (Justin Case via Getty Images)

In women, oestrogen is a key sex hormone that is needed for everything from bone strength, to menstruation, and pregnancy – but scientists have now found that this hormone could also be why women are more likely to find it harder to quit smoking than men.

After data suggested that women can become dependent on nicotine, which is the stimulant drug in cigarettes, after less exposure than men, researchers in the US decided to investigate why this is.

Scientists at the University of Kentucky wanted to understand why women struggle more with quitting cigarettes than men, and discovered that it could be due to hormones.

The team, led by PhD student Sally Pauss, found that oestrogen induces the expression of olfactomedins, which is a type of protein that is involved in the brain’s processing of reward and addiction.

Nicotine has been proven to suppress olfactomedins – which means the interaction between oestrogen, nicotine, and olfactomedin in women may be the reason they struggle more with addiction.

"Our work hoped to understand what makes women more susceptible to nicotine use disorder, in order to reduce the gender disparity in treating addiction to nicotine," Pauss said of the study published in the journal ‘American Society for Biochemistry and Molecular Biology’.

"Our findings have the potential to better the lives and health of women struggling with substance misuse. If we can confirm that oestrogen drives nicotine seeking and consumption through olfactomedins, we can design drugs that might block that effect by targeting the altered pathways.

"Hopefully, these drugs would make it easier for women to quit nicotine."

women with e-cigarette
Nicotine is found in cigarettes and most e-cigarettes. (Getty Images) (rez-art via Getty Images)

To get these results, the team used large sequencing datasets of oestrogen-induced genes to identify which ones have a hormone function in the brain.

They found that only one class of genes met this criteria – those coding for olfactomedins – which prompted them to perform a series of tests to better understand the interactions between olfactomedins, oestrogen, and nicotine.

Results of the tests, conducted with human uterine cells and rats, suggested that oestrogen’s activation of olfactomedins — which is suppressed when nicotine is present — might serve as ‘a feedback loop’ for driving nicotine addiction processes.

"It is possible it does this by activating areas of the brain’s reward circuitry, such as the nucleus accumbens," Pauss explained.

The team are now looking to conduct further studies to definitively determine whether oestrogen contributes towards nicotine addiction.

Pauss said that this knowledge will be helpful for women everywhere, but particularly for those taking oestrogen in the form of the contraceptive pill or via hormone replacement therapy.

"This is because, if our findings are proven, these things could increase a woman’s risk of becoming addicted to nicotine," she said.

The latest data from the Office for National Statistics (ONS) suggests that around 14.6% of men (3.6 million men) in the UK are smokers, as are 11.2% of women (2.8 million women).

Those aged between 25 and 34 are the highest proportion of current smokers compared to any age group.

According to the NHS, smoking is one of the biggest causes of death and illness in the UK and each year around 76,000 people die from smoking-related causes.

If you are looking to quit smoking, you can visit the NHS Smokefree website, download the free NHS Quit Smoking app, or call the helpline on 0300 123 1044.

Additional reporting by SWNS.

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