Contraceptive pills might change women’s brains and make them risk takers, study suggests

Oral birth control may alter the part of the brain responsible for emotion, anxiety and fear, possibly making women on the pill more likely to engage in unsafe behaviors.

Researchers from Canada studied 139 women aged 23 to 35 years old and found those taking oral contraception had thinner regions on their frontal lobe than those who had never taken or had stopped taking OCs.

This thinning is thought to impact social conduct and impulsivity, possibly leading to women on OCs having lower inhibitions, taking more risks and having less fear.

The team said more research needs to be done, but their results suggest exposure to sex hormones plays a role in the structure of the nervous system. 

Alexandra Brouillard, a researcher at Université du Québec à Montréal and first author of the study, told DailyMail.com her team identified that the effect of current OC use on this brain region was associated with the exposure to synthetic estrogen present in the pills

More than 150million women use oral contraceptives across the globe and birth control pills are between 93 and 99 percent effective at preventing pregnancy

Brouillard said: ‘In our study, we show that healthy women currently using [oral contraceptives] had a thinner ventromedial prefrontal cortex than men. 

‘This part of the prefrontal cortex is thought to sustain emotion regulation, such as decreasing fear signals in the context of a safe situation. 

‘Our result may represent a mechanism by which COCs could impair emotion regulation in women.’

More than 150million women use OC across the globe and birth control pills are between 93 and 99 percent effective at preventing pregnancy.

OC is generally considered safe, but there are some risks, including breast soreness, mood changes, weight gain and stroke. 

Among the female subjects, 62 were currently using oral contraception, 37 had previously used OC and 40 women had never taken the pills. Researchers also included 41 men for comparison.

The team took conducted MRIs to study the gray matter volume and cortical thickness of regions in the brain involved in processing information, regulating emotions, retaining memories and controlling muscles, as well as sensory perception and decision-making. 

Gray matter – sometimes referred to as grey matter – is known as the cortex of the brain and makes up the outermost layer of the brain.

Increased cortical thickness is thought to be associated with intelligence and thinning is associated with cognitive impairment. 

Compared to men, all three groups of women had larger gray matter volume in a part of the brain associated with learning, self control and executive control. 

This could be one reason men are generally more impulsive than women.  

The study also found that only women who were currently taking birth control showed thinning in a part of the brain responsible for processing risk and fear and controlling emotions. 

Thinning of this area is thought to cause inhibition deficits, or the loss of social conduct and impulsivity, particularly as it relates to the function of the amygdala, which is gray matter involved with experiencing emotions. 

An impaired amygdala lessens fear conditioning – when a person comes to associate something with a negative outcome and has a fearful response. 

This may lead to women on OCs having lower inhibitions, taking more risks and having less fear in unsafe situations. 

However, Brouillard told DailyMail.com researchers still have to investigate if their anatomical findings relate to significant changes in behavior or mental status.

She said it would be ‘too presumptuous’ to conclude these brain changes directly relate to riskier and more unsafe behaviors.

However, scientists do know these areas of the brain are involved with such behaviors. 

Brouillard said women prescribed birth control are made aware of the physical effects of the medication, such as a lack of period and ovulation. 

However, the impact of OCs on brain development are rarely addressed. 

Considering how widespread the use of birth control is, it is important to better understand the pills’ current and long-term effects on brain anatomy and emotional regulation, the researchers said. 

Brouillard added: ‘The objective of our work is not to counter the use of COCs, but it is important to be aware that the pill can have an effect on the brain. 

‘Our aim is to increase scientific interest in women’s health and raise awareness about early prescription of COCs and brain development, a highly unknown topic.’

The study was published Tuesday in the journal Frontiers in Endocrinology.