When we consider common women’s health issues, Alzheimer’s disease (AD) wouldn’t naturally come to mind. However, women over 60 are more likely to experience Alzheimer’s than breast cancer. Statistics have shown that women are more heavily diagnosed with this disease compared to men. In fact, in the United Kingdom the ratio of female to male Alzheimer’s patients is 2:1.
Why are women so greatly impacted by this disease? Of course, a clear reason for this difference is the increased average life expectancy of approximately 4 years. But this is not the whole truth.
What is Alzheimer’s disease?
Alzheimer’s disease is the most common disorder under the umbrella term of ‘dementia’. This family of illnesses affect 850,000 nationally and costs the NHS £26.3 billion annually. Dementia is the 7th leading cause of death globally and the rate of annual patients seems to only be increasing. Despite these alarming statistics, there is a clear lack of detailed research into the illness – this often makes diagnosis challenging.
Key symptoms of the disease include: memory loss, decreased cognitive skills and difficulty carrying out daily tasks. The primary physiological feature of the illness is the formation of beta-amyloid plaques in the brain and a loss of neuronal connectivity. Shockingly, these features can occur up to 20 years before any symptoms are displayed. These changes originate in regions such as the hippocampus – a structure associated with memory.
As discussed, there is a major lack of research into Alzheimer’s sex prevalence. This is primarily due to issues with funding and diagnosis difficulties. Diagnostic issues can arise from factors such as distrust in the healthcare system, lack of awareness and shortage of specialists. This article will investigate some of the proposed potential links between sex and this illness.
Depression and menopause link
Depression is very prevalent in those with AD and it is often difficult to distinguish between the two diseases as they share common features. Typically women are estimated to have a higher chance of depression than men and this is believed to increase the chance of Alzheimer’s disease by up to 70%.
The onset of the menopause elevates the risk of depression due to shifts in hormone levels. It is thought that these changes in oestrogen levels alter the structure of the brain to change its function. Oestrogen impacts neurotransmitters, such as serotonin and norepinephrine, which play key roles in regulating depressive symptoms. It is believed that oestrogen acts as a protective barrier to the formation of amyloid plaques.
There is a huge social pressure placed on women going through the menopause. Where this natural change is viewed as a negative. It is often overlooked how impactful this can be on an individual’s mental health. Menopause not only affects a woman’s physiology but also their brain function.
Autoimmune disease risk
It has been shown that there is a strong correlation between the formation of amyloid plaques in the brain and Alzheimer’s. Autoimmune diseases, like multiple sclerosis, cause an increase in these plaques which may be part of the brain’s response to infection. In fact, it was suggested that up to 20% of people with an autoimmune disease will experience a form of dementia later in life.
It is acknowledged that women face an increased risk of having an autoimmune disease. Whilst the exact reason why is unknown, it is thought that pregnancy strengthens the individual’s immune system.
Studies have demonstrated that the most influential factors would include sleep patterns and socioeconomic status. Circadian irregularity is very common in AD patients. The production of peptides associated with formation of plaques are the highest when sleep disturbances occur.
Further to this, the rate of education for women in the U.S. has gradually increased over the last few years and there has been a corresponding decline in cases of Alzheimer’s disease. Whilst it is impossible to distinctly say this is the cause, it could be a possible link.
Hope for future research?
It is impossible to definitively say why women are so disproportionately affected by this illness. However, the World Alzheimer’s Report 2021 addresses this issue in further detail. The clear findings are that awareness campaigns and sex-specific brain screenings for those over 50 could have considerable influence on the rate of illness. It is extremely encouraging that these steps are going to be taken in future healthcare and research to reduce the sex gap of Alzheimer’s disease.