Sex and gender differences in cognitive and brain reserve: Implications for Alzheimers disease in women

Women represent (2)/(3) of the cases of Alzheimers disease (AD). Current research has focused on differential risks to explain higher rates of AD in women. However, factors that reduce risk for AD, like cognitive/brain reserve, are less well explored. We asked: what is known about sex and gender differences in how reserve mitigates risk for AD? We conducted a narrative review of the literature, with keywords: "sex/gender differences", "cognitive/brain reserve", "Alzheimers Disease", and the following cognitive reserve contributors: "education", "IQ", "occupation", "cognitive stimulation", "bilingualism", "socioeconomic status", "physical activity", "social support". Sixteen papers disaggregated their data by sex. Those papers observed sex and gender differences in reserve contributors. There is also evidence that greater reserve may be more beneficial in lowering AD risk in women, although more research is needed. We discuss how traditional reserve contributors are gendered and may not capture factors that support cognition in aging women.Funding Agencies|Canadian Consortium on Neurodegeneration and Aging; Wilfred and Joyce Posluns Chair in Womens Brain Health and Aging (the Womens Brain Health Initiative, Ontario Brain Institute); Wilfred and Joyce Posluns Chair in Womens Brain Health and Aging (Canadian Institutes of Health Research)Canadian Institutes of Health Research (CIHR); Canadian Institute of Health ResearchCanadian Institutes of Health Research (CIHR) [PJT 201610-153321, GS9-171369]; Natural Science and Engineering Research CouncilNatural Sciences and Engineering Research Council of Canada (NSERC) [RGPIN-2018-05761]; Alzheimers Society; Natural Science and Engineering Research CouncilNatural Sciences and Engineering Research Council of Canada (NSERC)