Can you tell someone's biological age from their face?
Your face does emit biological signals, but it is too limited and too variable to measure your biological age accurately. Take facial ageing seriously as a possible indicator, but do not rely on it as a measure of your health.
Facial ageing does reveal something about biological age, but it is only one piece of a larger puzzle. People aged 60 and over who felt they looked older than their peers had a 61% higher chance of developing dementia in the years that followed, according to a large British study with more than 195,000 participants. That association held up even after adjusting for known risk factors such as a genetic predisposition to Alzheimer's disease. This is a correlation, however, not a proven causal relationship.
Specific wrinkles, such as crow's feet, were linked to cognitive decline in a smaller Chinese study of 612 people. The quarter with the most crow's feet had more than twice the rate of cognitive impairment compared with the quarter with the fewest. However, that study measured everything at a single point in time and had a small group of participants, so caution is warranted here.
The face is therefore not a reliable thermometer for your overall biological age. Large-scale organ research shows that different organs and systems each have their own pace of ageing. Facial features are one signal among many, alongside blood markers, immune function, gut microbiota and more. Chronological age alone is already a poor measure of biological ageing, and a single facial feature is even more so.
The eyes are perhaps the most informative part of the face. Cataracts and macular degeneration (damage to the central field of vision) are direct expressions of ageing in the eye. Interestingly, these eye diseases share biological mechanisms with Alzheimer's disease, Parkinson's disease and cardiovascular disease. In this way, the eye offers a kind of window onto how the body ages as a whole.
Genetic research further suggests that facial ageing is partly determined by biology and heredity, through genes in immune cells that also influence other ageing traits. What this means in practical terms for, say, a blood test or lifestyle advice is not yet clear. Oral health, including tooth enamel, gums and salivary glands, also provides age-related signals, but is an incomplete measure: smoking accelerates it considerably, and severe gum disease is a disease rather than ordinary ageing.
Claims are based on PMID 39506848 (large prospective UK Biobank study and smaller Chinese cross-sectional study), PMID 35263580 (multi-omics organ ageing), PMID 40659289 (genetic-immunological study, Mendelian randomisation), PMID 27501493 (oral ageing), PMID 38977082 (eye ageing), PMID 40110678 (immune function and biological age).