A condition that affects millions of American women has been associated with an increased risk of developing Alzheimer's disease. A new review has set out to understand what could be behind the potential connection.
Researchers across the U.S. and Iran said that having polyendocrine metabolic ovarian syndrome (PMOS), formerly known as polycystic ovary syndrome (PCOS), has been linked with an increased risk of cognitive vulnerability and dementia, and outlined possible mechanisms behind the connection.
However, they said that clinical evidence showing a link between PMOS and Alzheimer's disease remains "inconsistent" and focus should "remain on optimizing metabolic health" while further investigation is conducted.
The experts conducted a thorough search of data through October 2025 to come to their conclusions. The review was published online in the Journal of the Endocrine Society on October 13.
"The findings align with our research linking metabolic alterations with cognitive function in PMOS," Marla Lujan, a professor of nutritional sciences at Cornell University, told Newsweek. "We need more mechanistic studies to fully capture how reproductive hormones might alter Alzheimer's disease development in PMOS."
"This article presents food for thought," Shruthi Mahalingaiah, a professor of environmental reproductive and women's health at Harvard University, told Newsweek, adding it is "important to study the potential long-term effects of PMOS on cognition and neurological health."
However, she added that "we should be careful not to present the current evidence reviewed in this article as demonstrating a clear, independent dementia risk," as available studies are "limited and inconsistent." She said, at the same time, the research could "offer an important opportunity for prevention."
...
What Is PMOS?
PMOS is a condition where cysts, which are small sacs of fluid, develop on the ovaries. This can lead to irregular menstruation and is a common cause of infertility. The condition is believed to affect 10 to 15 percent of women worldwide.
Other symptoms include acne, hair growth, darkening of the skin in body creases, weight gain and more. It is understood that imbalances in hormones could play a role in the symptoms.
It is known that PMOS can increase a woman's risk of developing a number of diseases including type 2 diabetes, gestational diabetes (which is diabetes during pregnancy), heart disease, high blood pressure, high cholesterol, sleep apnea and stroke, as well as depression and anxiety.
What The Review Found
Mina Amiri, the first author of the study and an assistant professor at Tehran University of Medical Sciences, told Newsweek that one of the studies reviewed was a retrospective Canadian cohort of more than 16,000 women with PMOS and almost 50,000 age-matched controls, where a higher dementia prevalence was found among those with PMOS, alongside a younger age at onset.
Although, another study included was a prospective UK Biobank analysis of around 1,000 women with PMOS and around 5,000 age- and BMI-matched controls, which found no significant association with all-cause dementia.
"The differences between these studies likely reflect study design, diagnostic criteria and, most importantly, how well each adjusted for metabolic factors such as BMI and insulin resistance," she said. "Studies that account for these factors show a much weaker association or none at all."
Therefore, they said that "direct evidence of Alzheimer’s-type changes in the brains of women with PMOS is lacking. The existing biomarker findings come from blood tests and are strongest in women with obesity or insulin resistance."
"Research needs large, long-term studies following women across the reproductive lifespan, and randomized trials with cognitive outcomes, to clarify whether PMOS independently affects dementia risk," she said.
Although, she added that healthcare providers "should continue to focus on metabolic health, through lifestyle measures and insulin-sensitizing treatment where indicated."
How PMOS Could Increase Dementia Risk
Mahalingaiah said there is research suggesting that "metabolic co-morbidities, particularly insulin resistance, obesity and related cardiometabolic risk, may account for much of the observed association."
These factors, alongside sleep disturbances, are both "common in PMOS" and things that are "known to increase Alzheimer's risk," Dr Anuja Dokras, a director of the University of Pennsylvania Polyendocrine Metabolic Ovarian Syndrome Center, told Newsweek.
"It is likely that these metabolic and vascular factors are probably the main drivers of any increased cognitive risk rather than PMOS itself," she said.
Amiri also said that studies reported "mild differences in attention, executive function and memory, and some brain imaging differences, in women with PMOS," but that these changes appear to be "largely explained by insulin resistance and obesity rather than by PMOS itself."
"Hormonal factors such as elevated [luteinizing hormone (LH)], androgens and progesterone deficiency may play a smaller, additional role, but this is far less certain," she added. "These mechanisms are hypotheses, not proven causes."
Mahalingaiah added that this "reinforces the importance of early, individualized management of metabolic health, rather than framing PMOS itself as inevitably leading to cognitive decline."
What Needs To Happen Next
Dokras said that women with PMOS "should not be alarmed by these findings," as while there is "increasing interest in the relationship between PMOS and cognitive aging, current evidence does not support routine dementia screening solely because of a PMOS diagnosis."
"The bigger takeaway is that PMOS is a whole-body condition with metabolic, endocrine, cardiovascular, and potentially neurological implications that deserve continued study," she said.
She added that large, long-term studies that follow women with PMOS across the lifespan are needed to "determine whether the condition independently increases dementia risk."
"In the meantime, the most important message is to focus on optimizing metabolic health through healthy lifestyle habits and management of cardiovascular risk factors, which are important for both overall and brain health," she said.
Mahalingaiah also said she would "welcome longer-term studies examining whether exercise, and different types or intensities of exercise, can prevent or reduce neurological and cognitive risk in people with PMOS. At present, that is a particularly important unanswered question."
Reference
Mina Amiri, Armita Kakavand Hamidi, Daniel L Farkas, Richard P Buyalos, Ricardo Azziz, (2026) Potential links between PCOS/PMOS and Alzheimer disease and related dementias. Journal of the Endocrine Society. https://doi.org/10.1210/jendso/bvag206
Newsweek’s reporters and editors used Martyn, our AI assistant, to produce this story. Learn more about Martyn here.
Contact Newsweek editors on this story: Kara Dolman and Paul Donnelley.