Effects of BDNF polymorphism and physical activity on episodic memory in the elderly: a cross sectional study
Résumé
Background:
The 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.
Methods:
Two 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.
Results:
As 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.
Conclusion:
This study clearly demonstrates an interaction between physical activity andBDNF Val66Metpolymorphism
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