This 400-year-old Catholic saint’s body has amazed scientists with its preservation; discover the science behind

In the past century or so, it was the first time that remains of St. Teresa of Jesus—popularly referred to as St. Teresa of Avila—were being displayed for people to see. The ceremony at the Basilica of the Annunciation of Our Lady of Mount Carmel located in Alba de Tormes, in Salamanca province, of Spain, brought about a glorious moment for devotees of this Catholic saint. Since 1914, such an exposition by the saint had been done to the public last.This latest development began a new cycle of public adoration and attracted visitors from around the nation. Several in the crowd were clearly overcome. Some prayed silently, while others exhibited raw emotion—one woman put her hand over her mouth in awe, and another seemed to be crying upon viewing the body of the saint.St. Teresa of Avila, a famous mystic, reformer of the Carmelite order, and Doctor of the Church, died in 1582 at the age of 67. Her theological books and religious legacy have established her as one of the most revered people in Catholic history. Her body has been "mostly incorrupt", a process that still boggles both religious faithful and scientists, according to the Diocese of Avila.During the summer of 2024, church authorities opened up St. Teresa's tomb within a thorough analysis. Discalced Carmelite nuns, monks, and clergy participated in the process, examining her physical state thoroughly. The objective was to analyse the present state of her body and relics—her heart, left arm, and right hand—and to compare them with photographic documentation from the 1914 public exhibition.As reported by Father Marco Chiesa, not much has changed in the state of the saint's face and foot since they were last recorded more than 100 years ago. According to ET reports, a comprehensive 53-page anthropological report, published in March 2025, verified this observation. It observed the preservation of key body parts, including:These parts of the body still had identifiable skin, tissue, and muscle structure, all of which are rare in remains of such age.Additional examinations showed that St. Teresa's scalp still had brown hair, and her right eye still had a discernible iris and darkened eyelids. These are very rare indicators of physical preservation in remains of over four centuries.Advanced diagnostic equipment, such as X-ray imaging, was also utilised. The scans identified that St. Teresa had a number of chronic diseases while she was alive, some of which probably restricted her mobility. Whereas some people view St. Teresa's incorrupt body as miraculous, professionals look to natural causes. According to renowned anthropologist Professor Luigi Capasso, the preservation can be attributed to dryness of her tomb, making the environment unsuitable for fungal and bacterial decompositions. He labelled it a "unique natural occurrence," one that has immensely decelerated the natural process of decomposition.The Catholic Church is still walking a fine line between spiritual veneration of St. Teresa's remains and scientific investigation. Preservation procedures are being upheld to keep the saint's body from environmental and human degradation. Religious circles and academic communities view her remains as priceless—not just as holy relics but also as a subject of continued scientific investigation.Also Read | Is Earth in danger? NASA's alarming discovery of a star being consumed by a black hole sparks concerns