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Why Do Women With Dementia Outnumber Men 2:1?
Longer female lifespan is only part of the answer. And here is what women can do about it.
Of the 6.2 million people age 65 and older with Alzheimer’s in the United States, two-thirds are women . The question is why.
The most obvious answer (and the one with considerable data to support it) is that Alzheimer risk increases with age, and women tend to live longer than men. The median age at dementia onset in the United States is about 83 years for both men and women. But the average life expectancy for men in the U.S. is 76.1 years. For women, it is 81.1 years .
But the story is a little more complicated than that. A study of over 26,000 middle-aged men and women found that women outperform men in this age range on measures of global cognition, executive function, and memory. The problem is that as they age, women suffer significantly faster declines in global cognition and executive function, but not memory. So this means that as women age, they enjoy greater cognitive reserve than men, but when that reserve starts to decline, they suffer a steeper fall-off .
Except however, for women who use hormone replacement therapy (HRT) following menopause.
Researchers at the University of Arizona’s College of Medicine and the Center for Innovation in Brain Science investigated dementia risk among 375,000 women aged 45 years and older. They found that HRT was associated with significantly reduced risk of all forms of dementia, including Alzheimer’s disease. And the longer the women had been on HRT, the lower the risk of developing dementia. Important caveat: Not all HRT formulations were equally effective: Natural steroid formulations yielded the greatest protective effects. The greatest reduction in dementia risk was observed in women aged 65 years or older.
But what about breast cancer or blood clot risk, you say?
Early studies reported an association between HRT and increased risk of breast cancer and blood clots. But more recent research tells a different story. And that is because of the rise in bioidentical hormones, that is, hormones that are compounded from natural sources that more closely resemble human hormones than do synthesized hormones or hormones extracted from pregnant horses. Synthetic progesterone turns out to be particularly risky. Here are the specific findings:
“Natural” 17 β Estradiol is significantly more effective than conjugated equine estrogen with or without synthetic progestin .
Bioidentical progesterone (micronized) does not increase the risk for deep vein thrombosis (DVT).
Micronized progesterone and dydrogesterone are likely to be associated with a lower risk of breast cancer compared to that seen with other progestogens.
Topical estradiol (creams or gels) do not increase the risk of blood clots, whereas the oral synthetic Prempro® does pose that risk .
Bio-identical testosterone with and without bio-identical estradiol was found to significantly reduce the risk of breast cancer.
Modern HRT seems to be not only safer for postmenopausal women than earlier versions in terms of cancer and blood clot risk, it is also protective against dementia.
Copyright Denise D. Cummins, PhD Nov 22, 2021
‘Super-Agers’ Perform as Well as Twenty-Year-Olds on Memory Tests
Worried that your memory will decline with age? You may be right to worry--unless you're a super-ager, that is.
A super-ager is an elderly person who performs as well as younger adults on tasks of cognitive function. They also don't show the typical brain shrinkage that usually develops as we age.
In a recent study, researchers scanned the brains of typical older adults (mean age 67), “super-agers” (mean age 66), and younger adults (mean age of 25) while they performed a very challenging memory test. The test required the participants to view 80 pictures of faces or scenes that were paired with an adjective, such as an image of a city paired with the word “industrial”, and to decide whether the word matched the image.
Ten minutes later, each participant was shown the same 80 image-word pairs, along with 40 new pairs and 40 rearranged pairs, such as the city image they’d seen previously now paired with the word “rural”. Their job was to indicate whether each word-image pair was “old”, “new”, or “rearranged”.
Younger adults typically outperform older adults on this kind of task. That’s because when we’re young, our brains are organized into distinct groups of neurons that respond selectively to different categories of images: Some groups respond strongly to faces, others to house, others to trees, and so on. As a result, it is easy to create and retrieve vivid and distinct memories of what we see. But as we age, these distinct populations become less choosy. Subsets that used to respond primarily to faces now respond to other images as well. That makes it more difficult to form and retrieve distinct memories for the things we see.
Unless you are a super-ager, that is.
The super-agers in this study not only out-performed typical older adults on the memory test, their performance equaled the performance of younger adults. Brain scans revealed why: The scans of superagers in this study were found to have the same degree of differentiation as the younger adults, and far exceeded that of the typical older adults.
Were the brains of super-agers just naturally more efficient than their peers, or did they intentionally developed strategies to compensate for the decline of the aging brain—ones that can be taught? That is the next question the investigators plan to investigate.
The study was published in the scientific journal Cerebral Cortex on June 30, 2021. https://academic.oup.com/cercor/advance-article-abstract/doi/10.1093/cercor/bhab157/6311553?redirectedFrom=fulltext
Copyright Denise D. Cummins, Nov 18, 2021
Dr. Denise D. Cummins is cognitive scientist, author, and elected Fellow of the Association for Psychological Science. In this blog, she writes about the latest exciting findings in cognitive science so you can stay informed about brain health, mental health, and decision-making power. Her latest book is Good Thinking: Seven Powerful Ideas that Influence the Way We Think (2nd Edition, 2021)