Research Shows Why the Risk of Alzheimer’s is So Much Higher for Women

Not only are women more likely to develop Alzheimer’s and other forms of dementia, but new research also suggests that they may be more severely affected by various common risk factors for cognitive decline. Scientists at the University of California San Diego School of Medicine analyzed data from more than 17,000 middle-aged and older adults and found that certain modifiable risk factors for dementia appear to have a greater impact on women’s cognitive function than on men’s. The findings were published in Biology of Sex Differences.

“Beyond the question of which risk factors are most common, we found that some have a disproportionately greater impact on women’s cognitive abilities,” said Dr. Megan Fitzhugh, assistant professor of neuroscience at the UC San Diego School of Medicine and first author of the study. “This suggests that preventive measures may be more effective if they are tailored not only to the prevalence of risk factors but also to how strongly each factor affects women’s cognitive abilities compared to men’s.” The researchers say the findings could help explain why women account for nearly two-thirds of Alzheimer’s cases in the United States.

Women Bear a Greater Alzheimer’s Burden

Nearly seven million Americans currently live with Alzheimer’s, and women account for the majority of these cases. In Europe, too, women are significantly more likely to be affected by Alzheimer’s and other forms of dementia than men. Experts now speak of a “gender-specific Alzheimer’s burden,” as women not only develop the disease more frequently but also often live with it longer and, in addition, take on a large share of the caregiving responsibilities. Although women generally live longer than men, scientists say that longer life expectancy alone does not fully explain this discrepancy.

Researchers are increasingly investigating how biological, social, and lifestyle factors interact to influence the risk of dementia differently in women and men. Many of these factors can potentially be modified through medical care or lifestyle adjustments. For the new study, Fitzhugh and lead author Judy Pa, PhD, a professor of neuroscience at the UC San Diego School of Medicine, examined 13 established dementia risk factors using data from the “Health and Retirement Study,” a nationally representative sample of middle-aged to older U.S. adults. The factors included educational level, hearing loss, smoking, alcohol consumption, obesity, depression, physical inactivity, high blood pressure, diabetes, and other cardiometabolic diseases.

Key Dementia Risks affect Women and Men Differently

The analysis revealed several notable differences between women and men. Women were more likely to report:

• Depression (17% versus 9% among men)
• Physical inactivity (48% compared to 42%)
• Sleep disturbances (45% compared to 40%)

The women in the study also had a slightly lower average level of education, which is considered a risk factor for later cognitive decline. The following values were higher among men: High blood pressure was widespread in both groups, affecting about six out of ten participants. The average body mass index for both genders ranged from overweight to obese.

• Hearing loss (64% compared to 50% in women)
• Diabetes (24% compared to 21%)
• Heavy alcohol consumption (22% compared to 12%)

Some Risk Factors Had a Stronger Impact on Cognitive Function in Women

The researchers found that several risk factors were more strongly associated with poorer cognitive performance in women than in men. Conditions related to heart and metabolic health, including high blood pressure and a higher body mass index, showed a stronger negative association with cognitive performance in women. Hearing loss and diabetes, although more common in men, were also associated with lower cognitive scores in women.

Researchers suspect several causes for this. Hormonal changes after menopause play an important role. Estrogen normally protects blood vessels, nerve cells, and blood flow to the brain. With menopause, this protection decreases significantly, which means that high blood pressure, vascular damage, and metabolic problems could have a greater impact on sensitive brain regions. This may increase susceptibility to Alzheimer’s and other neurodegenerative diseases.

Diabetes also appears to harm women more severely. Elevated blood sugar levels promote inflammation, damage small blood vessels in the brain, and impair the energy supply to nerve cells. Studies suggest that women may be more sensitive to these metabolic changes than men. Additionally, it is believed that hormonal differences and inflammatory processes exacerbate the progression of the disease. Another notable factor is hearing loss. Although men are affected more frequently, women with hearing problems often exhibit more severe cognitive impairments. Experts suspect that social isolation, communication stress, and emotional strain play an important role in this. Since social interaction is closely linked to mental activity, hearing impairments could indirectly increase the risk of dementia.

In addition, Alzheimer’s disease sometimes progresses differently in women. Women can often compensate for early symptoms for longer, for example through better language skills or a higher so-called cognitive reserve. As a result, the disease often goes unnoticed for longer and is frequently diagnosed only when significant changes in the brain have already occurred. Overall, the findings show that dementia does not develop in the same way in all people. The same risk factors can affect women significantly more than men. For this reason, scientists are increasingly calling for gender-specific research as well as more individualized prevention and treatment strategies. Particularly important for women are good control of blood pressure and blood sugar, sufficient exercise, social activity, and early medical screening. “These differences underscore how important it is to consider gender as a key variable in dementia research,” said Pa. “Gender-specific differences are severely neglected in many of the most common causes of death, such as Alzheimer’s, heart disease, and cancer.”

Toward More Personalized Dementia Prevention

The new research findings support the approach known as precision medicine. This involves tailoring prevention and treatment more closely to individual factors—such as gender, genetic predisposition, lifestyle, or metabolism. Scientists increasingly believe that general recommendations alone are not sufficient to effectively prevent dementia. Instead, it might make more sense to specifically target those risk factors that have the greatest impact on brain health in certain population groups.

Especially in women, it appears that classic risk factors such as high blood pressure, diabetes, depression, or lack of exercise can have a more significant impact on cognitive performance than in men. That is why researchers are calling for more individualized prevention. For women, this could mean detecting cardiovascular diseases earlier, monitoring blood pressure and blood sugar more consistently, and paying closer attention to psychological stress. Regular exercise is also becoming increasingly important, as physical activity not only protects the heart but can also reduce inflammatory processes in the brain and improve blood circulation. Depression, in particular, is increasingly becoming a focus of dementia research. Studies show that depressive symptoms occur more frequently in women and may be associated with an increased long-term risk of cognitive impairment. Chronic stress, sleep problems, and social isolation also influence hormonal and inflammatory processes in the body, which may contribute to damage to nerve cells. Experts therefore suspect that mental health is a far more important component of dementia prevention than previously assumed.

Another focus is on cardiovascular health. Untreated high blood pressure is considered one of the most significant modifiable risk factors for dementia. In women, high blood pressure could have a particularly negative effect on small blood vessels in the brain, especially after menopause, when the protective influence of estrogen decreases. This may increase susceptibility to circulatory disorders, inflammation, and protein deposits, which are typical of Alzheimer’s disease.

The researchers also emphasize that many risk factors are fundamentally modifiable. This means that prevention could actually make a difference—especially if measures are started early. In addition to medical treatment, social and societal factors are also considered important. Women are more likely to take on caregiving responsibilities, experience chronic stress more frequently, and, in some regions, have poorer access to healthcare or preventive services. Such stressors could also affect brain health in the long term. Why dementia risks manifest differently in women than in men has not yet been fully clarified. Discussions focus on hormonal changes, differences in the immune system, genetic factors, and gender-specific differences in metabolism and brain structure. Certain risk genes, such as APOE-e4, appear to have a stronger influence on the risk of Alzheimer’s in women than in men.

Researchers view these findings as an important step toward smarter and more targeted prevention strategies. The goal is not to treat dementia only in old age, but to identify and reduce risk factors individually decades earlier. A more nuanced understanding of gender-specific differences could help reduce the growing burden of Alzheimer’s and other forms of dementia in the long term—especially among women, who are disproportionately affected worldwide.