Science Explains Why Our Tendons Break Down with Age

Could certain protein differences in our tendons explain why this tissue breaks down over the years? A new study published in the journal Biological Chemistry examines tendon structure in horses, which are similar to those found in humans as both mammals face common injuries as they age. 

For their research, the study authors used a horse model to undertake a thorough analysis of all proteins and protein fragments existing in healthy and injured tendons.

Researchers at Queen Mary University of London (QMUL) along with others from the University of Liverpool collected data that showed how healthy, older tendons dealt with a greater amount of fragmented material within them. According to researchers, this suggested that accumulated damage over time had not been fully repaired.

While examining injured tendons, the team also found more evidence of protein breakdown. However, whilst in younger tendons, the cells were more active and busy working to repair damage, there was a high accumulation of different protein fragments in older tendons--suggesting that the cells somehow lost their ability to repair much of the damage as they aged.

"Normal function of tendons, such as the Achilles, is important not just for Commonwealth athletes but for everyday activities for ordinary people," said co-author Dr Hazel Screen, a Reader in biomedical engineering at QMUL's School of Engineering and Materials Science and Institute of Bioengineering, in a news release. "This is the first study of its kind, and provides evidence that the increased risk of tendon injury with ageing might be due to a reduced ability of tendon cells to repair damage effectively."