A recent study has revealed that long-term space travel, particularly missions to Mars, could significantly impact astronauts' heart health, building on previous research that identified heart issues upon their return to Earth.

To investigate these effects, scientist Jonathan Tsui developed human induced pluripotent stem cells into heart muscle cells, which were then placed on a flexible 'tissue chip' designed to simulate heart contractions.

These heart tissues were sent to the International Space Station (ISS) aboard the SpaceX CRS-20 mission in March 2020, where they were monitored for contraction strength and irregular beating patterns.

Real-time monitoring allowed scientists on Earth to receive data on tissue contractions every 30 minutes, providing insights into the health of the samples.

The study observed that irregular beating patterns emerged, with the interval between beats significantly increasing by day 19 of the experiment.

Microscopic examination of the space samples revealed disordered protein strands and swollen mitochondria, indicating deterioration compared to ground samples.

Notably, the study found that key structural components of the heart muscle, known as sarcomeres, became disordered and shorter, suggesting potential heart disease.

Overall, the findings indicated that the heart tissue weakened, exhibited irregular beating patterns, and underwent genetic changes similar to those observed in aging.

The ongoing research aims not only to understand the impacts of space travel on heart health but also to identify drugs that could help maintain heart function in aging populations.

Led by Deok-Ho Kim, the research team included experts from multiple institutions, highlighting the collaborative nature of this investigation into cardiovascular health in space.

Following their return to Earth, the research team, led by Tsui, continued to maintain and collect data from the tissues over time.

The results of this significant study were published in the Proceedings of the National Academy of Sciences on September 24, 2024, emphasizing the need for a better understanding of weightlessness effects on heart function.