Skin carotenoids are inversely associated with adiposity in breast cancer survivors

Carotenoids are antioxidants which may mitigate some of the adverse effects of obesity, a condition associated with poor outcomes in breast cancer patients. We hypothesized that baseline skin carotenoids would be inversely associated with adiposity in breast cancer survivors and would increase with weight loss. Skin carotenoid score (SCS) was assessed by resonance Raman spectroscopy in breast cancer survivors (body mass index ≥25 kg/m²) enrolled in a 6-month randomized controlled weight loss trial (n = 47). Measurements included total body fat using dual-energy X-ray absorptiometry, height, weight, waist and hip circumference, dietary intake, and serum biomarkers. Associations between SCS, adiposity measures, and serum biomarkers were assessed at baseline, as was the change in SCS from baseline to 6 months, in the intervention and usual care groups. At baseline, SCS was inversely correlated with all adiposity measures (P ≤ .05). In multivariate analyses, baseline percent body fat had the strongest association with baseline SCS (partial R²= 0.20). Baseline SCS was significantly inversely associated with log C-reactive protein levels (regression coefficient β ± SE: -0.051± 0.019; P = .011) and log leptin (β ± SE: -0.019± 0.009; P = .046), but the associations were no longer significant after adjustment for adiposity. Over the 6-month study, the intervention group had a 17.6% increase in SCS compared to a 1.5% decrease in the usual care group (P = .28). In our study of overweight and obese breast cancer survivors, dual-energy X-ray absorptiometry-measured body fat explained a large portion of the variation in skin carotenoids at baseline, suggesting a stronger association than that previously seen in studies using less accurate measures of adiposity.