LOS ANGELES — New research gives some biological clues to why women may be more likely than men to develop Alzheimer’s disease and how this most common form of dementia varies by sex.

At the Alzheimer’s Association International Conference in Los Angeles on Tuesday, scientists offered evidence that the disease may spread differently in the brains of women than in men. Other researchers showed that several newly identified genes seem related to the disease risk by sex.

Two-thirds of Alzheimer’s cases in the U.S. are in women and “it’s not just because we live longer,” said Maria Carrillo, the association’s chief science officer. There’s also “a biological underpinning” for sex differences in the disease, she said.

advertisement

Some previous studies suggest that women at any age are more likely than men to develop Alzheimer’s. Scientists also know that a gene called APOE-4 seems to raise risk more for women than for men in certain age groups.

At the same time, women with the disease in its early stages may go undiagnosed because they tend to do better on verbal tests than men, which masks Alzheimer’s damage.

The new studies add more evidence and potential explanations for suspected variations between how men and women develop the disease.

Vanderbilt University researchers found differences in how tau, a protein that forms tangles that destroy nerve cells, spreads in the brains of women compared to men. Using scans on 301 people with normal thinking skills and 161 others with mild impairment, they mapped where tau was deposited and correlated it with nerve networks — highways that brain signals follow.

They found that tau networks in women with mild impairment were more diffuse and spread out than in men, suggesting that more areas of the brain were affected.

It’s long been known that women do better on tests of verbal memory — skills like recalling words and lists. University of California, San Diego, researchers found that women did better on these skills despite similar signs of early to moderate Alzheimer’s than men.

Using scans on more than 1,000 older adults, they found sex differences in how the brain uses sugar, its main energy source. Women metabolized sugar better, which may give them more ability to compensate for the damage from dementia and make them less likely to be diagnosed with it by tests that involve verbal skills.

“The female advantage might mask early signs of Alzheimer’s and delay diagnosis,” said study leader Erin Sundermann. “Women are able to sustain normal verbal performance longer,” partly because of better brain metabolism.

At the University of Miami, scientists analyzed genes in 30,000 people — half with Alzheimer’s, half without it — and found four that seem related to disease risk by sex.

“One confers risk in females and not males and three confer risk in males but not females,” said one study leader, Eden Martin.

Researchers don’t know yet exactly how these genes affect risk — or by how much.

“Some of these look like they’re tied to the immune system and we know there are differences between males and females” in how that works, said another study leader, Brian Kunkle.

Seven other genes seem to have different effect on risks in men versus women. The researchers have a National Institute on Aging grant to do an international study on nearly 100,000 people to try to validate and extend the results.

— Marilynn Marchione

Leave a Comment

Please enter your name.
Please enter a comment.

  • If it already proven that Alzheimers occurs more in women than in men, would it not be logical then to expect stepped-up research on hormonal & gender DNA, and the entire endocrine system? In these areas there does not seem to be much emphasis on R & D for Alzheimers. One wonders if that than also might lead to more effective approach also for ALS, Parkinson’s etc ?

  • Numerous studies have consistently shown that ‘rumination’ (regretting the past and worrying about the future, proliferating anger, etc.), is a transdiagnostic risk factor for the development of many mental health conditions. Since there is also evidence that women ruminate more than men, this finding in this article makes sense.

    • Men commit suicide more than women do, at all ages.

      This is a measurable outcome of depression, loneliness, lack of emotional support and perhaps genetic predisposition.

      The amount of time people spend ‘ruminating’ is yet to be measured.

      One man’s rumination may be another’s insightful reflection.

      Who knows? And who is willing to put aside the sense of superiority of their own sex?

    • You can check out the following article – there are gender differences in rumination:

      Johnson, D. P., & Whisman, M. A. (2013). Gender differences in rumination: A meta-analysis. Personality and individual differences, 55(4), 367-374.

      Also there is a huge difference between insightful reflection and typical rumination. The former cannot even be referred to as rumination because it involves analyzing a situation (it is a volitional act that can involve things like self-reflection). Typical rumination is an automatic process of being constantly engaged in thoughts such as regretting the past, worrying about the future, proliferating anger, etc.

    • Research on rumination can only be done via self reporting, it can’t be measured objectively in any way.

      It is well established that men tend to ignore health issues, including mental health issues.

    • Rumination can be measured objectively – you can check out the following article. There are other references too that I can provide.

      Garrison, K. A., Zeffiro, T. A., Scheinost, D., Constable, R. T., & Brewer, J. A. (2015).

      Meditation leads to reduced default mode network activity beyond an active
      task. Cognitive, Affective, & Behavioral Neuroscience, 15(3), 712-720.

  • It is my hope , wish . aspiration and advocacy that some where or some how there will come a time that this most serious ,lethal and mysterious super bug will be with in reality that there will be accurate and consistent worthy information as to this cause or causes of this super bug and that a remedy will be available to mitigate or have a positive result with lowering the ache .,pain suffering , depression . sadness and the devoid of just seeing some one you have known for an extended period of time . yet there comes this super bug within a short time and completely destroys or makes a radically change within the person that any one could not vision that this would take place . It is heart breaking to the core . thanks .Trevor Merchant . 4. 11 p.m day light savings time . New York City .

Your daily dose of news in health and medicine

Privacy Policy