Why does dementia disproportionately affect women? Sex differences in dementia: what the research reveals.

When we think of dementia, we often picture memory loss or confusion - but dementia is more than a disease; it’s a complex syndrome that steals independence, identity, and connection. And while it affects millions worldwide, it doesn’t affect everyone equally. In the UK, dementia has been the leading cause of death for women for over a decade.

Behind this stark statistic lies a troubling truth: women are not only more likely to develop dementia, but they also bear the brunt of its emotional, physical, and economic toll. From biology to caregiving to representation in research, the gender gap in dementia is wide - and closing it demands urgent attention.

So why are women more affected, and what can we do about it?

Dementia is not a single disease, but a syndrome, with a range of symptoms characterised by a significant decline in cognition that interferes with independent daily functioning. Each type of dementia has unique underlying causes, but all can be devastating to the lives of those affected. According to recent analysis by Alzheimer's Research UK, women are bearing a disproportionate weight of the impact. 

Dementia has been the leading cause of death for women since 2011. 

More than a decade ago, dementia became the leading cause of death for UK women - it has held this status ever since (1). While the male-to-female prevalence of dementia varies depending on the type, women have a higher lifetime risk of developing dementia overall. Alzheimer’s Disease (AD), the most common form of dementia, accounts for approximately two-thirds of women with dementia (2). This sex disparity in dementia prevalence has sparked increasing interest in the biological, social and environmental factors that contribute to this higher risk in women. 

So, why are women more affected?

One key factor is oestrogen, the primary female sex hormone, which is known to have neuroprotective effects. Oestrogen helps to maintain brain function by promoting neuronal growth and protecting against inflammation and brain cell death (3). However, as women reach menopause, their oestrogen levels decline, leaving the brain more vulnerable to damage and accelerating cognitive decline - particularly in the context of Alzheimer’s disease (4). 

Another important factor is longevity. Women tend to live longer than men, and because age is the most significant risk factor for dementia, this extended lifespan increases the likelihood of developing the condition (5). However, this is not the sole explanation. There are also sex differences in cognitive decline: once dementia begins, women often experience a faster progression of symptoms compared to men (6), suggesting that sex-specific biological differences influence disease progression. Understanding why this occurs is still an area of active research. 

Beyond biology, several social factors further compound women’s vulnerability. Women make up around two-thirds of unpaid carers of people with dementia. When formal care is unavailable, family members step in, often at great personal cost (7). Age UK has compiled a wide range of studies, finding that caregiving itself can increase the risk of cognitive decline in women due to stress, isolation and exhaustion. Approximately 61% of unpaid carers for people with dementia report that their caregiving responsibilities have negatively impacted their own health (8). Over 37% provide more than 100 hours of care each week, and around a fifth of women caring for someone with dementia have either reduced their working hours, or left the workforce entirely, to meet the demands of caregiving (9). 

Despite experiencing adverse reactions to drugs more often than men, women are less likely to be included in clinical trials. Women account for about 58% of clinical trial participants - which is lower than the percentage of people with dementia who are women - and therefore inaccurately represent the population. Only 6.7% of these trials report sex-specific outcomes and none provide sex-specific data on adverse events (10). The lack of sex-specific data is concerning, as it hinders the development of safe and effective treatments for women.  

Despite experiencing adverse reactions to drugs more often than men, women are less likely to be included in clinical trials. 

The sex gap also extends to the research workforce itself. Women make up 60% of dementia researchers, holding just 39% of senior roles (11). Between 2000 and 2020, only 37% of Alzheimer's Research UK grants were awarded to female researchers (12). These figures highlight a trend of women leaving academia at disproportionate rates prior to attaining senior positions - largely driven by work-life balance difficulties and a lack of adequate support structures. Tackling these issues is essential to ensure women are better represented in leadership roles in dementia research, promoting a more diverse research environment. 

What can we do about it?

To address the sex disparity in dementia research and care, several actions are needed:

• Promote sex-specific research - Clinical trials must include more women and report data by sex to develop treatments, considering factors like hormonal changes and caregiving roles.

• Support caregivers - Women who care for loved ones with dementia need better access to training, financial support, and respite care. To help balance caregiving with professional life, policies should offer flexible working and financial incentives.

• Empower women in research - Institutions should offer mentorship and work-life balance support to help women advance in dementia research. Equal access to grants and promotions is crucial for empowering women researchers (13). 

  
  

The good news is that the scientific community is starting to pay more attention to these sex differences, addressing the disparities in dementia care and research, leading to better outcomes for both women and society as a whole.

References

1. Alzheimer's Research UK (2021) The Impact of Dementia on Women. Available at: https://www.alzheimersresearchuk.org/about-us/our-influence/policy-work/reports/the-impact-of-dementia-on-women/

2. Alzheimer's Society (2021) Why dementia is different for women. Available at: https://www.alzheimers.org.uk/blog/why-dementia-different-women 

3. Stern, Y. (2020) 'The influence of gender on dementia risk and progression', Neurobiology of Aging, 88, pp. 185–194. Available at: https://www.sciencedirect.com/science/article/abs/pii/S0301008220301507 

4. Briceno Silva, G. et al. (2024) 'Influence of the onset of menopause on the risk of developing Alzheimer's disease', Cureus, 16(9), p. e69124. doi:10.7759/cureus.69124 

5. Zhu, D., Montagne, A. and Zhao, Z. (2021) 'Alzheimer's pathogenic mechanisms and underlying sex difference', Cellular and Molecular Life Sciences, 78(11), pp. 4907–4920. doi:10.1007/s00018-021-03830-w

6. Aggarwal, N. T. and Mielke, M. M. (2023) 'Sex Differences in Alzheimer's Disease', Neurologic Clinics, 41(2), pp. 343–358. doi:10.1016/j.ncl.2023.01.001

7. Giebel, C. et al. (2024) 'Do people with dementia and carers get what they need? Barriers in social care and carers needs assessments', Dementia, 23(4), pp. 550–566. doi:10.1177/14713012241237673

8. Carers UK (2024) State of Caring Survey. Available at: https://www.carersuk.org/policy-and-research/state-of-caring-survey/

9. Age UK (2020) Dementia Policy Position. Available at: https://www.ageuk.org.uk/siteassets/documents/policy-positions/health-and-wellbeing/dementia-policy-position-mar-2020.pdf

10.  Martinkova, J. et al. (2021) 'Proportion of Women and Reporting of Outcomes by Sex in Clinical Trials for Alzheimer Disease: A Systematic Review and Meta-analysis', JAMA Network Open, 4(9), p. e2124124. doi:10.1001/jamanetworkopen.2021.24124

11.  Andreou, M. et al. (2022) 'The dementia research career pipeline: Gender disparities in publication authorships and grant funding outcomes at different career stages', AMRC Open Research, 4, p. 18. doi:10.12688/amrcopenres.13072.1 

12.  Dementia Researcher (2021) Exploring gender composition of dementia researchers at different stages. Available at: https://www.dementiaresearcher.nihr.ac.uk/exploring-gender-composition-of-dementia-researchers-at-different-stages/  

13.  Alzheimer's Research UK, 2021. The impact of dementia on women. [online] Available at: https://www.alzheimersresearchuk.org/about-us/our-influence/policy-work/reports/the-impact-of-dementia-on-women/ 

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This article was written by Amy Harrison and edited by Rebecca Pope, with graphics produced by Suzana Sultan. If you enjoyed this article, be the first to be notified about new posts by signing up to become a WiNUK member (top right of this page)! Interested in writing for WiNUK yourself? Contact us through the blog page and the editors will be in touch.