In our complex world, we are called upon to deal with an impressive number of events that cause us stress. Our body's response to this stress is to produce cortisol. Several studies (Drewelies, 2021; Mendonça-de-Souza, 2007) document the link between cortisol in our blood and cognitive deficits.
Studies confirm that yoga practice, however, mitigates these effects by restoring balance in the body faced with stress. Gothe et al. (2016) recently demonstrated that a yoga session has a positive effect on working memory and inhibition control in both youth, adults, and the elderly.
Recall that executive functions refer to a subset of cognitive functions whose processes are goal-directed (i.e., planning, scheduling, working memory, task coordination, cognitive flexibility, abstract thinking, etc.). These executive functions help us stay on track and accomplish our daily tasks.
Background to Gothe's (2016) study.
"Prolonged activation of the hypothalamus-pituitary-adrenal system is thought to have deleterious effects on brain function. Neuroendocrine studies suggest that brain exposure to higher concentrations of cortisol contributes to cognitive deficits as we age. Mind-body techniques such as yoga have been shown to improve stress levels by restoring the body's sympathetic-parasympathetic balance. The purpose of this study was to determine if yoga practice moderated the stress response, resulting in improved executive function."
Sedentary, community-dwelling older adults (N = 118, mean age = 62.02) were randomized for 8 weeks to either a yoga group or a control group that practiced fitness and stretching. At baseline and after eight weeks, participants completed self-report questionnaires assessing their executive function, stress, and anxiety levels, and provided saliva samples to measure their cortisol levels before and after completing cognitive tests.
The yoga participants showed improved measures of executive function and an attenuated cortisol response compared to their stretching counterparts, who showed increased cortisol levels and poor cognitive performance in their follow-up. Changes in cortisol levels as well as self-reported stress and anxiety levels predicted observed performance on the empathy task, n-back working memory, and cognitive flexibility attached to task switching (β's = 0.27-0.38 and p's ≤ 0.05 for yoga; β's = -0.37-0.47 and p's ≤ 0.01 for stretching).
Eight weeks of regular yoga practice resulted in improved working memory performance mediated by an attenuated stress response that was gauged by self-report and objective measures of salivary cortisol. Thus, this study provides evidence that nontraditional physical activity interventions, such as yoga, may be useful in restoring balance to the HPA (hypothalamic-pituitary-adrenal) axis, which is responsible for cortisol production, in older adults, and thus prevent cognitive decline.
Gothe NP, Keswani RK, McAuley E. Yoga practice improves executive function by attenuating stress levels. Biol Psychol. 2016 Dec;121(Pt A):109-116. doi: 10.1016/j.biopsycho.2016.10.010. Epub 2016 Oct 26. PMID: 27794449.
Colcombe S, Kramer AF. Fitness effects on the cognitive function of older adults: a meta-analytic study. Psychol Sci. 2003;14(2):125–130. PubMed doi:10.1111/1467-9280. t01-1-01430
Gothe, Neha & Pontifex, Matthew & Hillman, Charles & Mcauley, Edward. (2013). The Acute Effects of Yoga on Executive Function. Journal of physical activity & health. 10. 488-495. 10.1123/jpah.10.4.488.
Baklouti S, Aloui A, Baklouti H, Souissi N, Jarraya M. Effects of Hatha yoga on cognitive functions in the elderly: a cross-sectional study. Libyan J Med. 2022 Dec;17(1):2080799. doi: 10.1080/19932820.2022.2080799. PMID: 35657065; PMCID: PMC9176371.
Pauly T, Drewelies J, Kolodziejczak K, Katzorreck M, Lücke AJ, Schilling OK, Kunzmann U, Wahl HW, Ditzen B, Ram N, Gerstorf D, Hoppmann CA. Positive and negative affect are associated with salivary cortisol in the everyday life of older adults: A quantitative synthesis of four aging studies. Psychoneuroendocrinology. 2021 Nov;133:105403. doi: 10.1016/j.psyneuen.2021.105403. Epub 2021 Aug 30. PMID: 34536776.
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