Alzheimer's disease affects millions worldwide, but one statistic continues to stand out: women are disproportionately diagnosed compared to men. In Canada and other developed countries, about two-thirds of those living with Alzheimer's are women. While the longer average lifespan of women has often been cited as the primary reason, emerging research suggests there may be more complex biological and sociological factors at play. This evolving understanding has significant implications for how we approach prevention, diagnosis, and care — especially when it comes to women's brain health and aging.

The story of Sonia Elizabeth Cox, shared by her daughter Angeleta Cox, illustrates the deeply personal impact of this disease. Sonia, a vibrant woman who immigrated from Jamaica to Canada in 1985, was diagnosed with Alzheimer's at age 64. Her daughter recalls how quickly the symptoms appeared: Sonia first forgot her husband, then struggled to recognize her son. Angeleta became her primary caregiver until Sonia's passing in late 2024. Her experience is not unique, but it highlights the urgency of understanding why women are more vulnerable to this devastating condition.

For many years, researchers attributed the higher prevalence of Alzheimer's in women to longevity. Age remains a strong risk factor, but scientists are now uncovering other contributors, including hormonal changes, reproductive history, and even surgical interventions. These findings are shifting the narrative and opening new avenues for research and treatment.

One area receiving increased attention is the role of menopause in brain health. According to several studies presented at the Alzheimer's Association International Conference (AAIC), early or premature menopause — defined as occurring before age 45 or even before 40 — is linked to a higher risk of developing Alzheimer's later in life. Dr. Walter Rocca, a researcher at the Mayo Clinic, emphasized that women who experience early menopause, whether naturally or through surgical procedures like oophorectomy, may face hormonal deficiencies that elevate their risk. Estrogen, which declines during menopause, has been shown to have neuroprotective effects, making hormone therapy a potential intervention for some women.

Gillian Einstein, a neuroscientist at the University of Toronto, highlighted findings from the UK Biobank, a large-scale health and genetics database. She noted that a longer reproductive period and having one to three children appear to lower the risk of Alzheimer's. Conversely, women who had their ovaries removed before age 50 showed increased risk, underscoring the importance of hormonal balance throughout a woman's life. Einstein believes the scientific community is at a turning point, with growing recognition of how sex and gender influence dementia risk. This shift was evident at the AAIC, where more sessions than ever focused on women's health and sex differences in brain aging.

Despite these advances, researchers acknowledge that women have been historically underrepresented in clinical trials and dementia studies. Natasha Rajah, a Tier 1 Canada Research Chair at Toronto Metropolitan University, is working to address this gap. Her current project, the Canadian Brain Health at Midlife and Menopause study (BHAMM), aims to detect early signs of Alzheimer's through brain scans and blood samples collected during midlife. Rajah is particularly focused on identifying how menopause may serve as a critical window for early intervention. She also emphasizes the importance of including diverse populations in research, noting that Alzheimer's studies in North America have often lacked racial and ethnic representation.

For families like the Coxes, this research is more than academic. Angeleta Cox reflected on her mother's early hysterectomy due to fibroids, a decision that may have unknowingly increased Sonia’s risk of Alzheimer's. Armed with this knowledge, Angeleta made different choices for her own health, opting against a full hysterectomy and prioritizing stress reduction and mental well-being. She’s also sharing what she’s learned with her daughter and through the Pan African Dementia Association, an organization supporting Black communities affected by dementia.

Alzheimer's disease remains incurable, but early detection and lifestyle interventions can help manage symptoms and possibly slow progression. Treatments include medications that address cognitive decline, as well as non-pharmaceutical approaches like physical activity and brain-healthy diets. As science continues to uncover the unique risks women face, these strategies may become more personalized and effective.

Understanding why more women get Alzheimer's is not just a matter of statistics — it's about improving lives. When women are affected, the impact ripples through families and communities. As research becomes more inclusive and nuanced, there is hope that future generations will face fewer uncertainties and more options in the fight against Alzheimer's.

Read more at cbc.ca