Alzheimer’s disease is a brain disorder that slowly destroys memory and thinking skills. As the disease progresses, individuals are eventually deprived of the ability to carry out the simplest tasks. In most people with Alzheimer’s, symptoms first appear later in life. Estimates vary, but experts suggest that more than 6 million Americans, most of them age 65 or older, may have dementia caused by Alzheimer’s. Almost two-thirds of these patients are women. Scientists have sought the reason for this disparity among Alzheimer’s disease patients.
Harvard scientists explored the reasons behind the mystery. One key factor, they write, could be age and life span. The average life expectancy for women in America is 81 years. For men, the average is 77 years. Most people with Alzheimer’s have the late-onset form of the disease in which symptoms become apparent in their mid-60s or later. Reason stands to show that women are more likely to be diagnosed with Alzheimer’s than men simply because women statistically live longer lives. The longer one lives, the more likely they are to develop symptoms of the disease.
Scientists, however, believe that this phenomenon is due to more than life expectancy.
One study followed 16,926 people in Sweden and found that beginning around age 80, women were more likely to be diagnosed with Alzheimer’s disease than men of the same age. Similarly, a study based in Taiwan found that one’s chances of developing Alzheimer’s disease over seven years were greater in women compared to men.
Additionally, a meta-analysis examining the incidence of Alzheimer’s disease in Europe found that approximately 13 out of 1,000 women developed Alzheimer’s every year, compared to only seven men. Therefore, women living longer than men is not seen as the comprehensive answer to why women are more likely than men to develop Alzheimer’s disease. Research has repeatedly demonstrated that even among individuals who are living and the same age, women are more likely to be diagnosed with Alzheimer’s than men.
The work of Harvard researchers suggests that amyloid, one component of Alzheimer’s disease pathology, may be deposited in order to fight off infections in the brain. Should this hypothesis be proven true, researchers may conclude that Alzheimer’s disease is a byproduct of our brain’s immune system. In parallel reasoning, women are known to have stronger immune systems compared to men. This is believed to be so in order to fight off infections in the fetus during pregnancy. As part of their stronger immune systems, women may end up having more amyloid plaques than men, thus making them more susceptible to Alzheimer’s.
Women may possess a higher risk for developing Alzheimer’s, but there are several steps that women can take to reduce their individual risk of the disease. Studies show that even if you are likely by family history — or simply by chance — to develop Alzheimer’s disease at some point in your life, you can delay the onset of the disease by staying cognitively and physically active. As scientists continue to research the causes of this gender gap in Alzheimer’s, women can use this knowledge to stay as mentally and physically healthy for as long as possible.
Article by Rhonda Errabelli