Why brains are a women's health issue
Article #1 of Raising our voices, even louder! A women's health long-read content series
Welcome to the first in my new monthly content series, where I take a deep dive into core women's health topics.
I share articles of interest through my newsletter, but I wanted to get stuck into a subject with the help of some experts.
This content series will cover big topics in an approachable way. Consider my newsletter the snappy intro and these pieces the robust long-read.
First up, one of my favourites - brain health!
My fascination with neurology
Slowly but surely, we're beginning to learn more about our brains, one of the most complex organs in our body. Since 1995, over 50,000 neuroimaging articles have been published. Exciting, right?
But, you may not be surprised to hear that only 0.5% of neuroscience research looks at women's health1. This is despite the fact that conditions affecting the brain, such as migraines and anxiety disorders, disproportionately impact women. And, of course, all these conditions are also chronically underfunded compared with their disease burden.2
Finally, however, women's health neuroscience is getting the attention it deserves. Projects such as Ann S. Bowers Women's Brain Health Initiative at the University of Santa Barbara give us hope for the future.
Recent fascinating findings in this space include the role of hormone exposure to our long-term brain health and the connection between ADHD and the menstrual cycle.
My mind is blown (ha) by how little we know now and the potential impact of what we'll find out.
Plus, with research comes innovation. As we learn more about our brains, tech can help us control and enhance this knowledge. One company doing precisely that is Samphire Neuroscience, with whom I've partnered for this piece.
Co-founded by Emilė Radytė, an Oxford and Harvard neuroscience graduate, Samphire Neuroscience is building neurotechnology for women.
Who better to help us better understand the basics of our brains. Here's what I found out.
Sex and brains
We know that research is lacking on female-specific brain conditions, but is there a variation in how brains work between sexes? Does it matter that female brains are studied less than men?
Are there sex differences in brain health?
"Yes, in fact women are almost nearly twice as likely to be diagnosed with depression than men are. While a lot more research needs to be done in this field, the increased prevalence of depression correlates with hormonal changes in women, particularly during puberty, prior to menstruation, following pregnancy and at perimenopause, suggesting that female hormonal fluctuations may be a trigger for depression. This paper illuminates this further.
Women are also more susceptible to chronic pain, and their pain is more likely to be dismissed in a phenomenon known as the 'gender pain gap'. In modern studies performed on both sexes, scientists found that women are not only more likely to suffer from chronic pain – 70% of people with chronic pain issues are women–but they also feel pain more often, for longer periods, in more areas, and even more intensely. Moreover, about half of chronic pain conditions are more common in women, with only 20% having a higher prevalence in men.
Yet despite these stats, women's health research is notoriously underfunded and conditions that affect women more than men garner less funding1.
Both depression and chronic pain can be managed via brain stimulation, and that's why at Samphire we are taking a brain-centric approach to symptom management. We believe that by enhancing neuroplasticity and normal brain function we can help alleviate some of the most common and severe menstrual symptoms such as pain, depression and anxiety."
Do women's brains change through each cycle?
"This is another area where we need more research, but recent studies have shown the following:
Hormonal fluctuations during the menstrual cycle play a significant role in neuroplasticity. Research, including studies by Barth et al, has shown variations in the hippocampus' plasticity correlating with the menstrual cycle, particularly noting increased brain connectivity with rising oestrogen levels in the period before ovulation. The connection between oestrogen and brain health is supported by studies on early menopause that demonstrate the heightened risk of neuronal loss and increased vulnerability to Alzheimer's disease as a result of oestrogen reduction in the body.
In a recently published longitudinal study, Zsido and colleagues have found that changes in hippocampal sub-regions are closely tied to fluctuations in ovarian hormones. Increases in oestrogen levels have been linked to the expansion of the parahippocampal cortex, crucial for memory encoding and retrieval, while elevated progesterone levels have been associated with increased volume in the perirhinal cortex, important for processing sensory information and memory.
Further research from the University of California at Santa Barbara indicates that follicle-stimulating hormone (FSH) and other ovarian hormones can affect cortical thickness across the brain. The study observed that progesterone levels during the luteal phase can lead to variations in cortical thickness in different regions, suggesting a complex relationship between hormones and brain structure.
If we zoom in on the molecular level, research studies have shown a correlation between oestrogen and increased neuronal plasticity, partly modulated by increased levels of neurotrophic factors like Brain-derived Neurotrophic Factor (BDNF), a molecular indicator of neuroplasticity.
All of these studies demonstrate that the brain undergoes significant structural and functional changes as a result of hormonal fluctuations in the menstrual cycle."
How cool. What happens during the luteal phase - the phase after ovulation and before day one of your period?
"During the luteal phase, the surge in progesterone and fluctuating estrogen levels lead to significant changes in brain activity and mood.
A study by Li et al. (2021), revealed that hormonal changes are not just statistical data points but have tangible effects on brain function and, by extension, mood and cognition. The prefrontal cortex, a brain region pivotal for emotional regulation and cognitive processing, becomes less responsive to emotional stimuli during this phase. For women with PMDD (premenstrual dysmorphic disorder), this reduction is pronounced, mirroring patterns observed in depression.
To add to that, the luteal phase also triggers distinct changes in brain wave activity. Baehr et al. (2004) found that alpha waves, which are instrumental in mood regulation, exhibit notable imbalance or asymmetry during this phase. This isn't a harmless physiological shift. For women, particularly those with PMDD, this alpha wave asymmetry correlates with increased emotional sensitivity, mood swings, and episodes of depression.
In essence, the luteal phase isn't just a period of hormonal change but a phase where the very foundations of emotional and cognitive well-being are shaken up and recalibrated. Millions of women go through these drastic changes every single month, with little to no validation for their suffering."
We must acknowledge that final point. This isn't just in our heads. There are biological reasons for the feelings and difficult emotions being felt by millions of women. If we stopped talking about these issues and conditions in isolation and viewed them from a total body perspective, things really would be different.
Using our brain power to overcome our issues
The exciting thing about all this new research is the opportunity to use this new knowledge to enhance or protect our health.
We're all familiar with the term 'you can't teach an old dog new tricks' but, as it turns out, you absolutely can. Modern research3 suggests that our brains can develop well into adult life. Rather than finishing in our twenties, 'neuroplasticity' - the ability to form new brain connections – continues.
Now that we know this, how can we use it? Step in, neurotechnology.
"In academia, neurotechnology is the field of science and engineering in which the nervous system is interfaced with technical devices. It encompasses any method or electronic device which interfaces with the nervous system to monitor or modulate neural activity. The branch of neurotechnology that we work in is called neuromodulation. Neuromodulation is the alteration of nerve activity through targeted delivery of a stimulus, such as electrical stimulation or chemical agents, to specific neurological sites in the body.
Similar to the way a cardiac pacemaker can correct abnormal heartbeats, neuromodulation therapies can help to re-establish normal function of the nervous system."
I've heard people use the term neurohacking, what does that mean?
"Neurohacking, also sometimes called brain hacking, is understood as the attempt to optimise brain function and enhance mental wellbeing, cognitive performance, and mood.
At Samphire, we define neurohacking as the attempt to optimise brain function to enhance overall wellbeing. This is because we believe the brain is the control centre of our bodies."
How can neurotechnology help people with menstrual disorders? How can it support with pain?
"Neurotechnology methods like neuromodulation has shown great promise in the fields of depression and chronic pain management. When we look at the major symptoms of menstrual disorders, and especially the ones that interfere with lives, they can be categorised under mood and pain symptoms. Essentially, we are applying the same technology that is improving the livelihood of depression and chronic pain patients non-invasively and without severe side effects, to menstrual symptoms.
Our solution, Nettle, comes in the form of a medical-grade neurostimulation wearable, similar to Flow Neuroscience's device which in 2023 was clinically proven to be 2 times more effective than the 21 most common antidepressants. However, unlike Flow, which only targets the prefrontal cortex known for playing a role in mood regulation, Nettle will also target the motor cortex, which plays a role in pain perception. By targeting these two brain regions, Nettle is also the first at-home brain stimulation device that is designed to manage both chronic pain and mood symptoms.
The device itself uses a low electrical current in what is known as transcranial direct current stimulation (tDCS) to modulate neuronal activity. This stimulation increases neuroplasticity, meaning the brain's ability to change and adapt by forming and reorganising synaptic connections. The brain-uterus connection is surprisingly linear. Changes in hormone levels affect brain structure and activity. This means each phase of a menstrual cycle enacts changes in the brain itself, which affect mood, energy, sensitivity and more. This is especially pronounced during the luteal phase, when hormone levels tend to become imbalanced.
Due to the long legacy of misogyny within medical research, the science backing Nettle is still fairly young but growing every day. A study by Li et al. (2021), revealed that the prefrontal cortex – the brain region pivotal for emotional regulation and cognitive processing – becomes less responsive to emotional stimuli during the luteal phase. For women with more severe PMS (premenstrual syndrome) or PMDD, this decline is even more pronounced, resembling patterns observed in patients with clinical depression. The luteal phase also triggers distinct changes in brain wave activity. Baehr et al. (2004) found that alpha waves, which are instrumental in mood regulation, exhibit notable imbalance or asymmetry during this phase which correlates with increased emotional sensitivity, mood swings, and depressive episodes. An escalating body of research also looks at the bidirectional relationship between pain and mood. We now know that dysmenorrhea and depression amplify each other. Depression intensifies pain and pain exacerbates depression, creating a vicious cycle that can severely impact a woman's quality of life.
These findings underscore the critical necessity of a comprehensive approach to managing menstrual symptoms in a way that simultaneously addresses both physical pain and emotional well-being. Through Nettle, Samphire is doing exactly that, and this is only the beginning of the company's push to address women's health and wellbeing with effective, safe, and science-backed solutions."
Optimising brain health
The possibilities of neurotechnology are very, very exciting. Imagine the impact it can have on conditions like depression and dementia but also on wider areas such as hearing and movement.
Alongside trying out this new technology, what can we all do to support our brains? Samphire Neuroscience has got us covered.
Samphire’s top three brain health tips are:
· Do simple brain-training games timed for your menstrual phase
· Learn something new that challenges you, such as an instrument or a new language
· Use external tools, like non-invasive brain stimulation.
I told you neuroscience was cool! See you all on Duolingo.
Introducing Nettle
Samphire Neuroscience is launching Nettle, the world's first medical-grade neuromodulation wearable for PMS and menstrual pain. The medical-grade headband is a breakthrough in health technology. Experience life-changing improvements in pain, mood, and cognitive function in just 20 minutes a day.
The company built the proprietary neuromodulation technology specifically to solve the unique combination of mental and physical symptoms women feel due to their menstrual cycle. It offers the world's first medical-grade drug and hormone-free solution to symptoms associated with PMS, PMDD, PCOS (Polycystic Ovary Syndrome) and endometriosis.
Find out more and buy it here.
Keen to read more on the topic?
1. https://samphireneuro.com/blogs/its-all-in-your-brain/neuroplasticity-and-the-cycle-brain-connection
2. https://www.samphireneuro.com/blog/will-neuroimaging-revolutionise-the-diagnosis-of-pmdd
3. https://iuk.ktn-uk.org/health/neurotechnology/
4. The Women's Brain Foundation
References
Jacobs, E G. (2023) Only 0.5% of neuroscience studies look at women's health. Here's how to change that. Available at https://www.nature.com/articles/d41586-023-03614-1 (Accessed May 2024)
Smith, K. (2023) Women's health research lacks funding – these charts show how. Available at https://www.nature.com/immersive/d41586-023-01475-2/index.htm (Accessed May 2024)
Fuchs, E and Flugge, G. (2014) Adult Neuroplasticity: More Than 40 Years of Research. Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4026979/ (Accessed May 2024)