Effects of BDNF polymorphism and physical activity on episodic memory in the elderly: a cross sectional study

Abstract

BackgroundThe brain-derived neurotrophic factor (BDNF) concentration is highest in the hippocampus compared with that in other brain structures and affects episodic memory, a cognitive function that is impaired in older adults. According to the neurotrophic hypothesis, BDNF released during physical activity enhances brain plasticity and consequently brain health. However, even if the physical activity level is involved in the secretion of neurotrophin, this protein is also under the control of a specific gene. The aim of the present study was to examine the effect of the interaction between physical activity and BDNF Val66Met (rs6265), a genetic polymorphism, on episodic memory.MethodsTwo hundred and five volunteers aged 55 and older with a Mini Mental State Examination score ≥ 24 participated in this study. Four groups of participants were established according to their physical activity level and polymorphism BDNF profile (Active Val homozygous, Inactive Val homozygous, Active Met carriers, Inactive Met carriers). Episodic memory was evaluated based on the delayed recall of the Logical Memory test of the MEM III battery.ResultsAs expected, the physical activity level interacted with BDNF polymorphism to affect episodic memory performance (p < .05). The active Val homozygous participants significantly outperformed the active Met carriers and inactive Val homozygous participants.ConclusionThis study clearly demonstrates an interaction between physical activity and BDNF Val66Met polymorphism that affects episodic memory in the elderly and confirms that physical activity contributes to the neurotrophic mechanism implicated in cognitive health. The interaction shows that only participants with Val/Val polymorphism benefited from physical activity.

Personalising exercise recommendations for brain health: considerations and future directions

“…Self-reported higher levels of physical activity improved the Met-associated reduction in working memory in middle-aged men and women 72. As well, in older male and female Val/Val carriers, higher levels of self-reported physical activity were statistically associated with increased volume of the hippocampus,73 decreased dementia risk74 and better episodic memory 75. Engagement in a multimodal exercise programme also increased serum BDNF in male and female Val/Val carriers only 76.…”

996. The Effect of Exercise Training on Resting Concentrations of Peripheral Brain-derived Neurotrophic Factor (BDNF): A Meta-analysis

“…Few studies have assessed the potential impact of this SNP on the effect of exercise training on peripheral BDNF and brain outcomes. Findings from these reports suggest an increase in BDNF and improvements in memory after exercise only in those without the SNP [37, 133,137]. However, those findings are limited by the small number of studies.…”

“…This SNP is present in approximately 30% of the global population and is associated with altered secretion of BDNF as well as a possible increase in serum BDNF concentration relative to those without the SNP [134][135][136]. The presence of this polymorphism may alter the relationship between fitness and brain outcomes such as cognition, mood, and response to mood treatments [133,137,138]. Few studies have assessed the potential impact of this SNP on the effect of exercise training on peripheral BDNF and brain outcomes.…”

Effect of Physical Activity on Cognitive Development: Protocol for a 15-Year Longitudinal Follow-Up Study

“…In recent years, studies of the effect of physical activity on cognitive development are moving from descriptions of the relationship to in-depth explorations of the mechanisms [49–51]. The PACD study also seeks to investigate the possible role of plasma IGF-1 and BDNF in mediating activity-related cognitive development.…”