Rexbye · Age and ageing 2006 · cross-sectional twin study · n=1826

Influence of environmental factors on facial ageing.

Cited 197 times in the scientific literature.

Level 3 - non-randomized controlled study

Cross-sectional analysis within a longitudinal twin cohort

PubMed 16407433 · doi:10.1093/ageing/afj031 · record verified 2026-08-26

What was done

Data were evaluated from the 2001 wave of the population-based Longitudinal Study of Aging Danish Twins, including 1,826 twins aged 70 and older who had high-quality facial photographs taken. Ten nurses independently estimated the visual age of each participant from the photographs, and the mean of these estimates was used as perceived age. Determinants of facial ageing were analyzed using multivariate linear regression and intrapair comparisons among twin pairs, controlling for disease status.

What was found

In men, higher perceived facial age was significantly associated with smoking (P = 0.01), sun exposure (P = 0.02), and low body mass index (BMI) (P < 0.005), with number of children showing borderline significance. In women, low BMI (P = 0.05) and low social class (P < 0.005) were significantly associated with older perceived age, with marital status (P = 0.08) and depression scores showing borderline associations. Numerical effect estimates and regression coefficients were not reported in the abstract.

Why it matters

This study shows that non-genetic, modifiable lifestyle factors—including sun exposure, smoking, and body mass index—alongside socioeconomic markers are significantly associated with perceived physical aging in late life, with notable differences between men and women.

Limits

The study is cross-sectional in its visual assessment, precluding causal conclusions. Key quantitative effect sizes and confidence intervals were omitted from the abstract. Findings in Danish twins aged 70 and older may not generalize to younger age groups or diverse racial and ethnic populations. Exposure measures relied on self-reported survey data.

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