The body’s pace changes at around 50, study finds

The body does not seem to age like a clock that always ticks at the same pace: sometimes, its molecular workings change more quickly. A study led by researchers from the Chinese Academy of Sciences detected pronounced changes in numerous proteins across different tissues between the ages of 45 and 55, with an approximate turning point around 50. This is no cause for alarm on a milestone birthday: the authors do not claim that everyone suddenly ages when they reach that age.

To look for these changes, the team analysed 516 samples from 13 tissues taken from 76 donors aged between 14 and 68. In total, they examined more than 12,700 proteins. The research, conducted by Yingjie Ding and other researchers, was published in the journal Cell on 25 July 2025. It is a kind of molecular inventory of several organs, albeit a far more meticulous one than opening a drawer and wondering where all those cables came from.

When comparing samples from different age groups, the researchers found that the most marked changes in most organs were concentrated between the ages of 45 and 55. They also identified 48 disease-related proteins whose levels increased with age, including some associated with cardiovascular and liver conditions. The finding describes patterns in the samples studied: it does not make any particular protein a diagnosis or provide a way to predict what will happen to an individual.

The Chinese study is not the only one to have found periods of molecular change. A study from Stanford University, published in Nature Aging on 14 August 2024, followed 108 people aged between 25 and 75 and detected changes around the ages of 44 and 60. But these are different studies: Stanford’s examined molecules and microbes, while the Chinese study focused on proteins in tissues. So their age markers are not two dates to put in the diary as though the body had a staff meeting.

The pattern of changes does not begin everywhere at once, either. The Chinese team observed early changes in the aorta and adrenal glands at around 30. Near the age of 50, the aorta showed particularly marked remodelling. The researchers suggest that protein signals from blood vessels could affect other organs; this is a hypothesis put forward by the team, not proof that the aorta directs the ageing of the rest of the body.

There is an important difference between comparing people of different ages and following the same person over several decades. This study compared tissue from donors of different ages who had died from accidental traumatic brain injury. Its findings describe what was observed in those samples and help researchers investigate how organs change, but they do not establish a universal age or mean that the whole body changes suddenly. The body, like an office with many departments, can have different rhythms in each section.

Taken together, these studies suggest that molecular ageing may involve periods of more intense change, rather than a perfectly uniform progression. The ages highlighted are reference points for the patterns observed, not identical boundaries for everyone. As always with health concerns, speak to your doctor or pharmacist if you have any personal questions.

Did you know? In the Chinese study, the aorta and adrenal glands were already showing early changes at around 30.

By Neuro-IA Cortés, La Gaceta de Guardamar’s virtual writer on the human body, an artificial intelligence: produced using publicly available sources. Sources consulted: english.cas.cn, , big.cas.cn, med.. General information: this does not replace advice from your doctor or pharmacist.