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Alzheimer’s disease is a progressive neurodegenerative disorder that affects millions of people worldwide, leading to premature cognitive decline and memory loss. In recent years, studies have shown a significant sex-related difference in the prevalence of Alzheimer’s disease. Out of the over 5 million Americans with Alzheimer’s disease, about two-thirds of these cases are amongst women. So why is Alzheimer’s disease almost twice as common in women?

“One of the major reasons for this stark difference could be the fact that women live longer.”

One of the major reasons for this stark difference could be the fact that women live longer. In fact, 57% of all individuals ages 65 and older are female. The average lifespan for women is about 5 years longer than for men in the U.S., and about 7 years longer worldwide. As the risk of developing Alzheimer’s increases significantly with age, it makes sense that we would see more women with the disease. Additionally, women will likely experience potential environmental and lifestyle factors for a longer period of time due to the lengthier lifespan.

Just as there is no one single cause for the development of Alzheimer’s disease, however, there is no one simple reason for the existing sex related difference. There are likely many factors other than longevity that increase a woman’s chances of developing Alzheimer’s, many of which are unknown.

“During menopause, estrogen levels naturally decline in women, which may impact cognitive function…”

It has been proposed, for instance, that biological factors such as hormonal differences play a role. Hormones, specifically estrogen, play a major role in brain function and neuroprotection. Estrogen has been shown to promote brain plasticity, enhancing learning and memory processes in the hippocampus. In rats, the administration of estrogen has been shown to improve learning and retention and reduce “cognitive deficits”. During menopause, estrogen levels naturally decline in women, which may impact cognitive function and increase the risk of developing Alzheimer’s disease.

Additionally, body composition may be an important biological factor influencing the development of Alzheimer’s disease. On average, men have a higher percentage of muscle mass compared to women, which may have a protective effect. A recent study published in the British Medical Journal found that “lean mass might be a possible modifiable protective factor for Alzheimer’s disease,” although the exact reason is not well known.

“…women often become the primary caretaker in the case of family members becoming mentally or physically ill.”

Another important factor to consider is women’s societal role and expectations and the potential subsequent impact. Women are typically primary caregivers while many also maintain full time jobs outside of the home. Additionally, women often become the primary caretaker in the case of family members becoming mentally or physically ill.

Although this may not be the case for every woman, the pressure to fulfill many roles can lead to increased levels of stress and less time for stress management and, ultimately, poorer quality of sleep. Of course, these factors are difficult to study, and it is impossible to make broad generalizations, however these sociocultural factors could certainly have an impact on cognitive health.

The higher prevalence of Alzheimer’s disease in women is a complex and multifaceted issue. Lifespan, biological, environmental and sociocultural factors may all contribute to this sex-related difference in disease prevalence. Understanding these factors is essential to develop targeted prevention and treatment strategies that account for these differences.

“…there are many dietary and lifestyle factors that can prevent the onset of Alzheimer’s disease.”

Regardless of biological sex, there are many dietary and lifestyle factors that can decrease the risk of developing or slow the progression of Alzheimer’s disease. Consuming a nutrient dense diet, staying mentally and physically active, managing stress, aiming for good quality sleep, minimizing consumption of alcohol and maintaining a sense of community and social interactions can all reduce your risk of developing all the diseases making up the current epidemic of non-transmissible chronic diseases, including Alzheimer’s disease.