Throughout history, one means of progressing medicine was making the decision that one’s assumptions and definitions of disease were no longer consistent with the scientific evidence of one’s time and no longer served an individual’s health care needs. This applies to the field of medicine today with Alzheimer’s disease, which now requires a change of diagnosis and treatment.
Between 2000 and 2014, there has been an 89 percent increase in deaths due to Alzheimer’s. Deaths from Alzheimer’s have nearly doubled during this 14-year period, while those from heart disease — the leading cause of death in the United States — have declined nearly 14 percent. Today, Alzheimer’s is considered the sixth-leading cause of death and the fifth-leading cause of death for those ages 65 and older in the United States.
However, it is not as easy to label an individual with Alzheimer’s disease as it would seem because, according to the CDC, a person could only have died from Alzheimer’s if the direct cause of death is from the Alzheimer’s disease itself. However, Alzheimer’s disease frequently causes complications, which cause death. Thus, those that die from other diseases (for example pneumonia or heart attack) are often not considered to have died due to Alzheimer’s. This is why Alzheimer’s disease is often referred to as a “blurred distinction between death with dementia and death from dementia.” Women are at the epicenter of the Alzheimer’s epidemic. For example, “among those aged 71 and older, 16 percent of women have Alzheimer’s and other dementias, compared with 11 percent of men.” This can be seen by analyzing the biological, physiological and sociocultural aspects that cause sexual dimorphism in patients with Alzheimer’s disease.
A biomarker is an indicator of a biological state in the human body. Clinicians use these biomarkers to diagnose the presence — or absence — of a disease to provide treatment and analyze of the risk. Hormones are factors that define an individual as female or male biologically. Both genetic and hormonal variations contribute to the aspects that underlie sexual dimorphism of the brain. Furthermore, after menopause, women experience a brisk loss of estradiol and progesterone, two important sex hormones. Men also experience such abrupt declines in sex hormones, however, these declines are significantly more gradual. Additionally, because testosterone can be metabolized into estrogen, men do not experience this severe loss that women do. This shows the possible link between sex and Alzheimer’s disease.
In addition to the various biological explanations for the sex differences of dementia, the effects of sociocultural aspects should also be noted. Gender refers to the psychosocial factors that impact our identity and change our susceptibility to disease (via health perception, social and work-related stressors, personal and societal perceptions and patient-doctor relationships). Such factors that relate to gender identity that may contribute to an increased risk of Alzheimer’s include the following: education, occupation, smoking, drinking, diet and exercise.
Low education and occupational history have been associated with a higher prevalence of Alzheimer’s disease. As seen throughout history, men hold a greater percentage of upper management positions. This reinforces the need for men to keep mentally challenging themselves. The Seattle Longitudinal Study discovered that individuals in their study born from 1914 to 1948, versus individuals born from 1886 to 1913, had a higher cognitive performance at 70 years old and slower rates of cognitive decline. Furthermore, the difference between the younger and older cohorts was much greater for women than for men. This highlights the significance of gender-specific societal changes in an individual’s lifestyle over time by the impact that society has on cognitive aging.
Another aspect of culture that could explain why Alzheimer’s disease is more prevalent in women is cigarette smoking. Scientists have reported that cigarette smoking was indeed associated with a decreased risk of Alzheimer’s. Traditionally, men have a higher prevalence of smoking because it was more socially acceptable for men. Post 1920s and 1930s, more women have begun to smoke. However, women — generally — smoke less than men do. Thus, this explains the hypothesis that smoking reduces one’s risk of Alzheimer’s disease.
Furthermore, although a sex-specific and gender-specific focus on Alzheimer’s disease research is still not common, the prevalence and incidence of Alzheimer’s disease vary by sex and gender. There are significant sex and gender-specific risk factors for Alzheimer’s disease, for example, hormones, occupation and smoking. Not taking note of these would impede treatments and research. Thus, it is important to study biological, historical, social and cultural trends to determine whether or not there will be an impact on the future prevalence and incidence of Alzheimer’s disease. Understanding these sex and gender differences will further help us to define personalized treatments and preventative interventions for Alzheimer’s disease.
