A brand new research has offered proof of each genetic adaptation and physiological modifications among the many Haenyeo, a unique group of ladies in South Korea’s Jeju Island recognized for diving as much as 10 m underwater and as much as seven hours a day to gather shellfish.
“In a society where established traditions have historically shaped gender roles, the Jeju-Haenyeo culture has emerged as an exceptional phenomenon,” the UNESCO mentioned after together with the group in its ‘Intangible Cultural Heritage’ checklist in 2016.
The genetic variant recognized within the research could scale back pregnancy-associated hypertension dangers, in response to the researchers. The findings have been printed within the journal Cell Reports.
The researchers explored whether or not long-term diving follow and pure choice have formed distinct traits on this group, significantly with respect to bradycardia (the slowing of coronary heart fee), blood stress regulation, and genetic variants related to chilly tolerance and pregnancy-related cardiovascular stress.
The researchers studied 91 girls divided into three teams: 30 Haenyeo divers from Jeju, 30 non-diving Jeju ‘controls’, and 31 non-diving Seoul ‘controls’. The physiological knowledge collected included spleen quantity (utilizing ultrasound), haematological parameters like hemoglobin and hematocrit ranges, and cardiovascular responses throughout a simulated dive (immersing one’s face in chilly water whereas holding breath).
Haenyeo divers have been discovered to be extra bradycardic throughout simulated dives than each management teams, which the researchers mentioned instructed a sturdy diving reflex probably attributable to coaching. This mentioned, the people’ spleen sizes weren’t considerably totally different between Haenyeo and non-Haenyeo Jeju girls — regardless that each teams had bigger spleens than the contributors from Seoul. This, the researchers argued, mirrored regional components somewhat than genetic adaptation.
The Haenyeo and Jeju controls additionally had larger diastolic blood stress than the Seoul contributors throughout the baseline, dive, and restoration intervals. The distinction persevered even after the researchers adjusted for confounding variables, indicating a possible adaptive function that enhanced the power that pumped blood to the mind throughout dives. The systolic stress remained unchanged, nonetheless.
With whole-genome sequencing of 84 people from the cohort, the researchers confirmed that Jeju Island residents — each Haenyeo and non-Haenyeo — are genetically distinct from mainland Koreans. They estimated the populations started to diverge round 5,000-7,000 years in the past.
Finally, the staff used the instruments of inhabitants genetics to determine a number of gene variants strongly related to diastolic blood stress throughout diving. One particularly, known as rs66930627, was considerably extra frequent in Jeju residents and was linked to decrease diastolic stress, a trait they might have advanced to cut back the danger of hypertension throughout being pregnant.
The staff additionally discovered that this variant correlated with modifications within the expression ranges of another genes with recognized roles in immune modulation and hypertension. According to the researchers, this affiliation supported their speculation that pure choice among the many Haenyeo could have focused the rs66930627 variant to cut back the danger of preeclampsia in diving pregnant girls.
“The Haenyeo are amazing, and their incredible ability is written in their genes,” University of Utah geneticist and research coauthor Melissa Ilardo mentioned in a launch. “The fact that women are diving through their pregnancy, which is a really tough thing to do, has actually influenced an entire island’s people.”
Published – May 06, 2025 09:08 am IST
