Scientists revealed which people are biologically older than their age

Social isolation and feelings of loneliness are associated with a small increase in estimated biological age. The highest indicators were found in people who experienced both conditions simultaneously. The results of an analysis of nearly 310,000 participants have been published in the journal Health Psychology.

Researchers from Chinese medical institutions used data from 309,746 participants in the UK Biobank. Their average age at the start of the observation period was approximately 56 years, and the median duration of health monitoring reached 14.4 years.

Isolation and loneliness were assessed separately. The former reflected objective characteristics of social contact — living alone, infrequent meetings, and the absence of regular group activities. The latter reflected the subjective feeling of loneliness and the lack of someone to confide in.

Biological age was calculated using the PhenoAge formula based on blood markers associated with inflammation and organ function. Researchers then determined how much the result differed from what would be expected for the participant's actual age.

After accounting for lifestyle, socioeconomic conditions, and diseases, the most isolated group was on average older by this measure by approximately four months, while lonely participants were older by approximately three months. When the two factors were combined, the differences were the greatest.

These are small average differences in a calculated indicator. They should not be interpreted as a loss of a corresponding number of months of life or as a prediction for any specific individual. Observational data also do not allow for a definitive separation of the influence of social connections from reverse causation, in which declining health makes socializing more difficult.

The authors believe that objective isolation and subjective loneliness are important to study as distinct components of health.