Physical activity may help ward off depression in older people
The levels of depression biomarkers in healthy postmenopausal women were lower after 8 weeks of increased daily physical activity, suggesting that the intervention may prevent depression in older people.
The study involved 38 healthy postmenopausal women (mean age 70.2 years) who were randomized 1:1 to an active or a control group. Women in the active group were requested to increase their physical activity amount beyond their usual lifestyle, as quantified using a uniaxial accelerometer for 8 weeks; while control participants maintained their daily lifestyle. [J Phys Ther Sci 2019;31:408-413]
After 8 weeks, the active group saw a significant increase in their serum brain-derived neurotrophic factor (BDNF) from baseline (p<0.05) while no significant changes were detected in the control group.
“BDNF has been shown to be associated with memory impairment and depression especially in older adults,” said the researchers led by Dr Masaki Takahashi from Waseda Bioscience Research Institute in Singapore.
“Although a decrease in BDNF concentration with age is inevitable, many past studies have demonstrated that acute or chronic exercise could increase BDNF concentration and thereby reduce depression symptoms in older adults,” they explained.
Levels of serotonin, another biomarker for depression, also increased significantly in the active arm after 8 weeks (p<0.01) but not in the control arm.
There were no changes in serum derivatives of reactive oxygen metabolites or biological antioxidant potential in either group. According to the researchers, the lack of association with oxidative stress may be attributed to inadequate intensity of physical activity, which in the current study was mainly focused on daily based activity such as walking and housekeeping rather than systematic exercise training.
As no data on whether diet or sleep time and quality changed during the study, the researchers acknowledged that this limitation should be taken into account and that these factors be considered in future studies.
“The findings from the present study suggest that increasing daily physical activity could be effective in improving depression biomarkers. This may be useful for the prevention of depression in older adults,” said Takahashi and co-authors.
According to guidelines, moderate exercise for a minimum of 150 minutes or vigorous exercise for a minimum of 75 minutes over 3–5 days per week are recommended to promote health. [Med Sci Sports Exerc 2007;39:1435-1445; Circulation 2007;116:1081-1093]
“From the perspective of lowering physical function and decreasing high-intensity physical activity with ageing, it is important to increase the concentrations of BDNF by increasing physical activity aside from exercising in older adults,” stated the researchers.