- New research shows how hot flashes and night sweats might indicate a higher risk of Alzheimer’s disease.
- This study sheds light on how menopause symptoms like hot flashes may explain why women are more likely to develop Alzheimer’s.
- Experts explain the findings.
Nearly two-thirds of Australians with dementia are women. Though we still don’t know why women comprise the majority of cases, previous research has looked at the relationship between menopause and Alzheimer’s, including one study published earlier this year that found early menopause may increase the risk. Now, new research shows how a common menopause symptom, hot flashes, may indicate a higher risk of Alzheimer’s.
A study presented at the 2023 Annual Meeting of The Menopause Society in Philadelphia investigated if hot flashes are associated with adverse biomarkers, or signs, of Alzheimer’s disease. This study builds on previous research about the connection between hot flashes and brain health, including one 2022 study that found people who experience hot flashes tend to have more white matter hyperintensities, a brain biomarker that has been linked to an increased risk of Alzheimer’s disease.
The new study examined vasomotor symptoms, or hot flashes and night sweats, in 248 women with a uterus and at least one ovary ages 45–67. The participants were either late-perimenopausal or postmenopausal.
Researchers found that women who have hot flashes, particularly those that occur during sleep, may have a higher risk for Alzheimer’s. They also found that a greater number of sleep hot flashes was associated with an increased likelihood of Alzheimer’s.
“Among other things, these findings indicate that women who experience frequent hot flashes, particularly during sleep, may warrant AD [Alzheimer’s disease] dementia risk reduction efforts,” said lead author and psychologist Rebecca Thurston in a press release.
These reduction efforts may include preventative lifestyle habits (like following a brain-healthy diet and exercising regularly) and also consulting with your doctor about your risk factors.
How are hot flashes linked to Alzheimer’s risk?
Hot flashes are a common symptom of menopause, occurring as a result of erratic or diminished oestrogen production, says women’s sexual health expert Dr Sheryl A. Ross.
“Hot flashes at night are called night sweats and in this study, this was associated with a low-value biomarker called, amyloid B 42/20, suggestive of a higher risk of Alzheimer’s disease,” she explains.
The association of hot flashes during sleep and Alzheimer’s disease may indicate that disruptions in sleep patterns could contribute to Alzheimer’s risk, suggests gynaecologist and menopause expert Dr Anat Sapan. “Alternatively, oestrogen has neuroprotective effects, and its decline may affect brain health,” she adds.
Research has shown that Alzheimer’s is driven predominantly by reduced brain cell metabolism and increased inflammation, says neurodegenerative disease expert Dr Dale Bredesen.
“The reduction in estradiol [oestrogen], especially if rapid, represents a reduction in the [cell metabolism] in the brain, thus hormonal reduction is associated with both hot flashes and Alzheimer’s,” he explains.
Why are women at higher risk for Alzheimer's?
Although men also develop reduced hormonal support over time (a reduction in testosterone, for example), the decline in hormones for women is a steeper curve, so the drop is more rapid, triggering a reduction in brain cell support that is more severe than typically occurs with men, says Dr Bredesen. “However, it’s important to note that there are many other triggers for Alzheimer’s, so this is only one factor.”
There are many other risk factors, including diabetes, high blood pressure, chronic obstructive pulmonary disease, older age, sedentary lifestyle, poor sleep, unhealthy diet, and genetic risk factors, that are also associated with an increased risk of Alzheimer’s disease, says Dr Ross.
The bottom line
This small study establishes correlation between the occurrence of hot flashes and increased Alzheimer’s risk, but more longitudinal studies are needed to closely examine the relationship between decreased oestrogen levels and risk for Alzheimer’s, says neurologist Dr Shae Datta. “While correlation is important, it does not always mean that is the ‘cause’ for a disease,” she explains.
Still, this study highlighting the possible connection between nighttime hot flashes and Alzheimer’s risk underscores the significance of sleep and oestrogen for brain function, says Dr Sapan. “It is important to recognise this risk as well as the other physical, environmental, and genetic risks of [Alzheimer’s] and be proactive.”
Menopause hormone therapy can not only help alleviate menopause symptoms but also potentially reduce the risk of Alzheimer’s, adds Dr Sapan.
These results suggest that “all women who are entering perimenopause or menopause should consult their doctors about their risk factors for cognitive decline to discuss the best plan for preventing cognitive decline,” adds Dr Bredesen.
Educating yourself on all the risks associated with Alzheimer’s disease is helpful in learning ways to prevent it, says Dr Ross.
“Eating a colourful and healthy diet similar to the Mediterranean diet, exercising 150 minutes per week, minimising alcohol intake, not smoking, sleeping seven to eight hours a night, and practicing mindfulness, will reduce your risk of chronic medical problems and your risk of Alzheimer’s disease,” she adds.
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