A recent genetic study focused on a group of female extreme divers in Korea has revealed notable genetic adaptations that may aid in their ability to withstand the physical challenges of free-diving. This research, published in Cell Reports, explores the extraordinary capabilities of the Haenyeo, women who have dedicated their lives to diving in the frigid waters surrounding Jeju Island.

The Haenyeo divers, renowned for their remarkable endurance, typically dive up to 60 feet deep to collect various marine resources, including seaweed and shellfish. The practice, integral to the region's cultural and economic history for centuries, has seen a decline, with most divers now in their senior years.

In an effort to understand the genetic factors contributing to the Haenyeo's exceptional diving abilities, researchers assessed several physiological metrics, including heart rate and blood pressure, and analyzed the DNA of the participants. This investigation uncovered two significant genetic variations that appear to enhance their underwater performance.

Adaptations for High-Pressure Diving

One of the key findings is that Haenyeo divers possess a genetic mutation associated with lower blood pressure during dives, a trait that is more prevalent among them than in the general population of mainland Koreans. This adaptation could be crucial for maintaining safety while diving, particularly for those pregnant, as it may help mitigate the risks of blood pressure-related complications.

Breath-holding during dives can elevate blood pressure, presenting potential health risks. The genetic change identified in the Haenyeo may play a protective role, allowing them to dive safely even during pregnancy and avoid conditions like preeclampsia, which can pose serious health threats.

Cold Tolerance and Pain Resistance

Additionally, the researchers noted a second genetic variation linked to pain tolerance, specifically in relation to cold exposure. Despite the chilling winter temperatures near Jeju Island, the Haenyeo continue to dive year-round, showing resilience to the cold that most would find unbearable. While the study did not quantitatively measure cold tolerance, the researchers plan further investigations to explore this intriguing aspect of Haenyeo physiology.

The distinct genetic traits that support the diving capabilities of the Haenyeo are part of a broader genetic landscape present among the Jeju Island population. However, the combination of these genetic factors, along with decades of diving experience, positions the Haenyeo uniquely in terms of their diving efficiency.

Research has consistently indicated that both trained and untrained individuals experience a decrease in heart rate when diving as a mechanism to conserve oxygen. For the Haenyeo, who have spent their lives mastering this skill, their heart rate reduction is significantly more pronounced than that of untrained individuals, further enhancing their diving capabilities.

Implications for Health Advancements

The discoveries stemming from this study could have far-reaching implications for medical science, particularly in terms of improving treatment for conditions associated with high blood pressure, including stroke. The low stroke mortality rates observed on Jeju Island suggest that these genetic adaptations might offer protective benefits against such health issues.

By understanding the genetic mechanisms that empower the Haenyeo, researchers hope to uncover insights that could benefit broader populations facing similar health challenges.