Neuroscientist finds her brain shrinks while taking birth control

yikes and it is subtle and a complete surprise.   I wonder if it applies also to other organs as well and does this impact the nervous system?

We do have now well over fifty years of meta stats to reassure us.

So it is hard to get worked up.  yet now we know.

Neuroscientist finds her brain shrinks while taking birth control

A researcher who underwent dozens of brain scans discovered that the volume of her cerebral cortex was 1 per cent lower when she took hormonal contraceptives

By Grace Wade

22 October 2024

Before now, no one had studied the brain before, during and after taking hormonal birth control

https://www.newscientist.com/article/2452737-neuroscientist-finds-her-brain-shrinks-while-taking-birth-control/

The largest brain imaging study of a woman to date shows that hormonal birth control can decrease brain volume – though it isn’t clear what effect, if any, this has on brain function.

Hormonal contraceptives have been around since the 1960s. Yet scientists only began investigating their potential effects on the brain in the past decade or two, says Carina Heller at the University of Minnesota. Previous studies have shown differences in brain volume between women who take hormonal contraceptives and those who don’t. But no one had studied the brain before, during and after taking hormonal birth control.

Heller, who was 30 years old at the time the study began, had previously used hormonal birth control once for 12 years but had stopped taking it about five years before the study.

The researchers scanned Heller’s brain using magnetic resonance imaging (MRI) five times a week, at the same time each day, for five weeks while she wasn’t using birth control. She then started taking birth control pills that contained synthetic forms of both oestrogen and progesterone – one of the most popular forms of contraception in many countries including the US and the UK. Three months later, Heller underwent 25 more brain scans across five weeks. She then stopped using the oral contraceptive and, three months later, repeated the scanning procedure for a final five weeks, marking 75 total brain scans.

As part of the study, Heller measured her body temperature and provided a blood sample before each scan to determine what phase of her menstrual cycle she was in. She also completed daily psychological questionnaires to track her mood and anxiety levels and logged her sleep, and how much water, alcohol and caffeine she drank each day. Heller tried to keep her physical activity and diet consistent throughout the study as well – one of the benefits of being your own study participant, she says.

The collection of brain scans created a detailed picture of how Heller’s brain changed across both her natural menstrual cycle and with hormonal contraception. However, the researchers didn’t capture her full menstrual cycle in the first 25 scans. “I had a prolonged cycle then,” says Heller, who presented these findings on 7 October at a Society for Neuroscience meeting in Chicago. So, they didn’t include them in their preliminary analysis.

The researchers found the volume of Heller’s cerebral cortex – the brain’s outermost layer – was 1 per cent lower while she was on birth control compared with when she stopped the medication. This is in line with previous studies that have indicated hormonal birth control may decrease volume in certain areas of the cortex.

Carina Heller underwent 75 brain scans to study birth control’s effects

Ann-Christine Buck

Heller says a decrease in cortical volume isn’t necessarily a bad thing. For instance, it also occurs during puberty and pregnancy when the brain refines neural pathways to make them more efficient. “This could be [happening] for the brain on oral contraceptives,” says Heller. “But for now, we don’t know what this means, and that’s why it’s so important that we do more research on the topic.”

It is also essential to remember that hormonal birth control affects people differently. Just because Heller experienced decreases in cortical volume doesn’t mean everyone will, she says. “You cannot generalise these findings to a larger population.”

Still, the work is a crucial step towards understanding why some people experience negative side effects, such as depression, on hormonal contraceptives while others don’t, says Natalie Tronson at the University of Michigan.