Holding Your Breath May Offer Unexpected Brain Benefits, Study Suggests

Holding one's breath for extended periods, a practice common in freediving, may offer surprising cognitive benefits, according to new research. While typically associated with the risk of hypoxia, the study suggests that regularly exposing the brain to low-oxygen states in a controlled manner could make it more resilient.

The research, detailed in a preprint study, focused on experienced freedivers, athletes who train to remain submerged underwater for several minutes on a single breath. The average person can hold their breath for 30 to 90 seconds, but top freedivers can endure much longer durations, with some setting world records exceeding 20 minutes. For most individuals, such prolonged oxygen deprivation would lead to hypoxia, a condition where brain cells can begin to die, causing symptoms ranging from dizziness to seizures and potentially permanent brain damage or death.

However, studies have observed that freedivers do not exhibit the cognitive impairments typically linked to hypoxia, nor do they show significant structural damage in the hippocampus, a brain region crucial for memory and navigation. To understand this phenomenon, researchers investigated the brains of 17 experienced male freedivers over seven months, comparing them to a control group of 20 physically active men who did not freedive.

Before and after the training period, participants underwent brain scans while breathing normally and while holding their breath. They also completed memory tests involving pairs of locations and hand gestures. The goal was to determine if changes in brain activity related to freediving correlated with improved memory recall.

Post-training scans revealed altered communication patterns in the divers' brains, particularly in regions associated with attention, decision-making, motor control, and sensory processing. The hippocampus showed stronger connections with the cerebellum, an area involved in motor coordination, memory, and cognitive functions. Concurrently, the hippocampus became less connected to areas related to movement and sensory processing, especially during normal breathing. Researchers hypothesize that the brain may be shifting focus from external stimuli to internal processes that support memory preservation under extreme conditions.

The memory tests indicated that divers with stronger connections between the left hippocampus and cerebellum were better at differentiating similar memories and recognizing new ones. Conversely, those with weaker connections between the right hippocampus and movement/sensory areas performed better at recalling previously seen memories. These findings suggest that repeated exposure to low-oxygen environments might alter hippocampal communication, potentially enhancing memory retention in freedivers.

The study authors propose that these insights could pave the way for new brain-training methods. Developing treatments that incorporate controlled periods of low oxygen might help the brain adapt and become more resilient, offering potential therapeutic approaches for age-related cognitive decline, neurodegenerative diseases, or conditions involving oxygen deprivation. However, the researchers caution that the study was small, and the control group was only scanned once, limiting definitive conclusions about causality. They also emphasize that freediving itself carries significant risks and should not be attempted without proper training and safety precautions.