A new study conducted by Finnish researchers has found that insulin resistance, a marker for type 2 diabetes, may be causing greater language problems, namely verbal fluency, and potential Alzheimer’s risk among women.
“Pre-clinical Alzheimer’s disease typically starts with episodic memory decline,” study author Dr. Laura Ekblad, a researcher at the University of Turku, told CBS News. “However, verbal fluency is a measure of executive function, and also deficits in executive function can be found early in the disease.” Executive function, she explained, is a form of higher thinking that mostly involves working memory, planning, and problem solving.
For the study, researchers examined the health of over 6,000 Finnish men and women between the ages of 30 and 97. With a wide variety of tests, researchers tested for verbal fluency by asking participants to name as many animals as they could in 60 seconds; then, they examined participants’ insulin resistance, as well as whether they had the gene APOEε4, a well-known precursor to Alzheimer’s disease.
The results showed women who had higher insulin resistance were also more likely to score very low on their verbal fluency exam. Interestingly enough, those who were found to have both higher insulin resistance and the APOEε4 gene did not seem to score as low on the verbal fluency exam, only those with higher resistance were impacted.
Researchers believe they’ve worked out a theory as to why that is. Previous research has shown that more women than men are affected by brain lesions called white matter hyperintensites (WMH), which are also known to be more common in those with metabolic problems like insulin resistance.
“White matter lesions seem to a play a role in Alzheimer’s disease,” researchers explained. “Therefore, the association between insulin resistance and cognitive functions could indicate that insulin resistance is a risk factor for Alzheimer´s disease.”
Already the fact that women seem to be more prone to developing dementia and Alzheimer’s has been a hot topic of research.
“The majority of people with Alzheimer’s disease are women. Women are about twice as likely to get Alzheimer’s disease,” Keith Fargo, director of scientific programs and outreach at the Alzheimer’s Association told CBS. “What we don’t know for sure is why.”
Ekblad said that this study does not necessarily prove causality: Due to the nature of the study’s design, they could only prove an association, and not a cause-and-effect model. This is to say not everyone with higher insulin resistance will develop cognitive problems or impairment later in life.
To Fargo, while the present findings are definitely an important discovery, there need to be more questions to the equation than answers.
“The only way we can get those answers is through more research,” he said. Although the study has proven that insulin resistance does have gender-specific effects on cognitive ability, researchers are still not 100 percent sure why, or what this means for the future of women’s health.
As for now, Ekblad suggests women be mindful of their diets and other lifestyle factors known to help prevent type 2 diabetes. Maintaining a healthy, active lifestyle doesn’t just combat diabetes, but also cognitive decline.