{"id":36765,"date":"2026-09-13T14:02:00","date_gmt":"2026-09-13T18:02:00","guid":{"rendered":"https:\/\/www.ecoticias.com\/en\/?p=36765"},"modified":"2026-09-13T12:01:41","modified_gmt":"2026-09-13T16:01:41","slug":"off-jeju-island-older-women-vanish-beneath-the-waves-on-one-breath-and-science-is-finally-measuring-what-their-bodies-learned","status":"publish","type":"post","link":"https:\/\/www.ecoticias.com\/en\/off-jeju-island-older-women-vanish-beneath-the-waves-on-one-breath-and-science-is-finally-measuring-what-their-bodies-learned\/36765\/","title":{"rendered":"Off Jeju Island, older women vanish beneath the waves on one breath, and science is finally measuring what their bodies learned"},"content":{"rendered":"\n

You may not believe this, but off Jeju island in South Korea some women in their 80s and 90s are slipping beneath the waves without air tanks or safety lines. Their work is to descend as deep as 20 meters and look for shellfish between the volcanic rocks. They can keep doing that for hours, and some of them have been doing it for more than 60 years.<\/p>\n\n\n\n

These haenyeo<\/a> (or women of the sea) are preserving far more than a dangerous job. New research done with them suggests that decades of breath-hold diving<\/a> have trained their hearts to conserve oxygen. It has also shown that the islanders and the next generations may have genetic signatures linking to lower blood pressure during dives. The sad part is that women carrying this culture are aging much faster than new divers can replace them.<\/p>\n\n\n\n

What a day in the water really looks like<\/h2>\n\n\n\n

Their equipment is simple. A haenyeo carries a mask, lead weight, a hook tool and a floating \u201ctewak\u201d with a net beneath it. The tewak is a small buoy that is used as a flotation device to help the haenyeo stay afloat in the sea and also serves as a sort of life jacket. In 2016 UNESCO<\/a> added the culture of Jeju\u2019s haenyeo to its Representative List of the Intangible Cultural Heritage of Humanity.<\/p>\n\n\n\n

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It might be crazy to you, but those divers can work up to 7 hours a day on 90 days each year. Most of those dives reach around 10 meters, although more experienced women may work at twice that depth<\/a>. When they resurface they release air with a whistling, just like whales and dolphins. This exhalation method is called \u201csumbisori\u201d. The workers are divided into 3 ranks, determined by skill. And the senior sangguns guide the others, because nobody dives alone.<\/p>\n\n\n\n

\"Jeju
Jeju haenyeo carry their diving equipment and tewak floats, which provide support at the surface and hold nets for their catch.<\/figcaption><\/figure>\n\n\n\n

Their bodies have learned to stretch one breath<\/h2>\n\n\n\n

In May 2025, a team led by University of Utah geneticist Melissa Ilardo<\/a> compared 30 haenyeo to 30 non-diving women from Jeju and 31 women from mainland Korea. The participants averaged 65 years old. Researchers tried to \u201csimulate dives\u201d by asking the participants to hold their breath and place their face in cold water.<\/p>\n\n\n\n

The haenyeo\u2019s heart rates fell more sharply than those of other women, helping their bodies use limited oxygen more efficiently. In one specific case described by Ilardo, a diver\u2019s heart rate dropped by more than 40 beats per minute in less than 15 seconds. This response appears to be largely tied to training, showing what years of repeated dives can teach the body<\/a>.<\/p>\n\n\n\n

The genetic clues that were found<\/h2>\n\n\n\n

The study also found some traces that cannot be attributed to their practice. The haenyeos were more than 4 times as likely to carry both a genetic variant associated with lower blood pressure during diving and a genetic variant linked to a higher cold tolerance than mainland Korean women.<\/p>\n\n\n\n

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Yet non-diving women from Jeju carried the same markers, making the island\u2019s divers and non-divers nearly indistinguishable genetically. Ilardo proposed that centuries of women diving during pregnancy may have created selective pressure because dangerously high blood pressure can threaten both mother and baby. Still, the study involved only 91 women, so a larger study has to be done if we want more solid conclusions.<\/p>\n\n\n\n

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