Walking for Cognitive Health: Previous Parity Moderates the Relationship Between Self-Reported Walking and Cognition

The Heterogeneity of Post-Menopausal Disease Risk: Could the Basis for Why Only Subsets of Females Are Affected Be Due to a Reversible Epigenetic Modification System Associated with Puberty, Menstrual Cycles, Pregnancy and Lactation, and, Ultimately, Menopause?

For much of human evolution, the average lifespan was <40 years, due in part to disease, infant mortality, predators, food insecurity, and, for females, complications of childbirth. Thus, for much of evolution, many females did not reach the age of menopause (45-50 years of age) and it is mainly in the past several hundred years that the lifespan has been extended to >75 years, primarily due to public health advances, medical interventions, antibiotics, and nutrition. Therefore, the underlying biological mechanisms responsible for disease risk following menopause must have evolved during the complex processes leading to Homo sapiens to serve functions in the pre-menopausal state. Furthermore, as a primary function for the survival of the species is effective reproduction, it is likely that most of the advantages of having such post-menopausal risks relate to reproduction and the ability to address environmental stresses. This opinion/perspective will be discussed in the context of how such post-menopausal risks could enhance reproduction, with improved survival of offspring, and perhaps why such risks are preserved. Not all post-menopausal females exhibit risk for this set of diseases, and those who do develop such diseases do not have all of the conditions. The diseases of the post-menopausal state do not operate as a unified complex, but as independent variables, with the potential for some overlap. The how and why there would be such heterogeneity if the risk factors serve essential functions during the reproductive years is also discussed and the concept of sets of reversible epigenetic changes associated with puberty, pregnancy, and lactation is offered to explain the observations regarding the distribution of post-menopausal conditions and their potential roles in reproduction. While the involvement of an epigenetic system with a dynamic "modification-demodification-remodification" paradigm contributing to disease risk is a hypothesis at this point, validation of it could lead to a better understanding of post-menopausal disease risk in the context of reproduction with commonalities may also lead to future improved interventions to control such risk after menopause.

Beyond sex differences: short- and long-term effects of pregnancy on the brain

Growing attention has been directed to the inclusion of females in neuroscience studies, and to the importance of studying sex as a biological variable. However, how female-specific factors such as menopause and pregnancy, affect the brain remains understudied. In this review, we use pregnancy as a case in point of a female-unique experience that can alter neuroplasticity, neuroinflammation, and cognition. We examine studies in both humans and rodents indicating that pregnancy can modify neural function in the short term, as well as alter the trajectory of brain aging. Furthermore, we discuss the influence of maternal age, fetal sex, number of pregnancies, and presence of pregnancy complications on brain health outcomes. We conclude by encouraging the scientific community to prioritize researching female health by recognizing and including factors such as pregnancy history in research.

Effects of exercise intensity and frequency on improving cognitive performance in middle-aged and older adults with mild cognitive impairment: A pilot randomized controlled trial on the minimum physical activity recommendation from WHO

Background: The World Health Organization physical activity guidelines recommend adults and older adults to accumulate at least 150–300 min of moderate or 75–150 min of vigorous aerobic-type physical activity weekly for health benefits including improvements of cognitive performance. However, the optimal exercise intensity and frequency for maximizing the cognitive benefits remain unclear.

Purpose: We conducted a parallel, assessor-blinded, pilot randomized controlled trial to evaluate the effectiveness of different intensities and frequencies of the WHO-recommended minimal volume of aerobic-type physical activity on improving cognitive performance in middle-aged and older adults with mild cognitive impairment (MCI).

Methods: Participants were randomly allocated to the stretching exercise control group (CON), once-a-week and thrice-a-week moderate-intensity walking groups (M1 and M3), and once-a-week and thrice-a-week vigorous-intensity walking groups (V1 and V3). Intervention duration was 12 weeks. The primary outcome was global cognitive performance assessed by the Hong Kong version of Montreal Cognitive Assessment. Secondary outcomes were self-report and objective cognitive performances, mental health, sleep quality, and cardiorespiratory fitness.

Results: Thirty-seven participants completed the study (CON: n = 7, M1: n = 7, M3: n = 7, V1: n = 8, V3: n = 8). Participants in all four walking exercise groups demonstrated significant improvements in global cognitive performance assessed by the Hong Kong version of the Montreal Cognitive Assessment after the intervention when compared to CON (p < 0.001). The walking exercise interventions also significantly mitigated the anxiety severity (p < 0.005) and improved the cardiorespiratory fitness (p < 0.05) of the participants in the walking exercise groups.

Conclusion: 150-min moderate- or 75-min vigorous-intensity walking exercise performed once- or thrice-weekly showed similar effects on improving cognitive performance in middle-aged and older adults with MCI. The 12-week walking exercise interventions also reduced anxiety severity and improved cardiorespiratory fitness of the participants.

Clinical Trial Registration:clinicaltrials.gov, identifier NCT04515563