Coffee and green tea polyphenol consumption was found to reduce skin photoaging and hyperpigmentation in a cohort of Japanese women, according to study data published in Clinical, Cosmetic, and Investigational Dermatology.
The cross-sectional study cohort comprised healthy, nonsmoking Japanese women, aged 30 to 60 years, who reported moderate daily sun exposure. Women with chronic skin diseases or who had undergone cosmetic skin treatments were excluded. Participants underwent a clinical examination of the facial skin, conducted using a digital photoimaging system. Ultraviolet (UV) Pigmented Spot (PS) scores were assigned to each individual based on the raw PS count. The rate of UV pigmented spot development was calculated by dividing PS count by number of years since age 18. Semistructured interviews were used to capture diet, environmental, and lifestyle factors, including polyphenol intake and average sun exposure. A total of 244 women were enrolled: 131 were interviewed in the summer and 113 were interviewed in the winter.
Mean age in the total cohort was 46.4±7.2 years. Total polyphenol consumption was negatively correlated with UV PS scores for both the winter (P =.013) and summer (P =.022) cohorts; in all subsequent analyses, winter and summer survey data were pooled. In the pooled cohort, total polyphenol consumption was negatively correlated with PS score (P <.001), raw PS count (P =.002), and the average area of pigmented spots (P =.002). Polyphenol consumption also appeared to slow the rate of hyperpigmented spot development; participants in the highest tertile of consumption had significantly lower hyperpigmentation development rates (P =.002). This trend persisted across all skin types and melanin indices.
Average polyphenol consumption was 1225±827 mg/d, with coffee and green tea accounting for 53% and 8% of total daily consumption, respectively. Although polyphenol consumption from any source was negatively associated with PS score, only coffee and green tea reached statistical significance. Polyphenols from coffee (P =.001) had a more significant association with PS scores than green tea (P =.029). Participants who reported high consumption of both coffee and green tea had the lowest overall PS scores (P <.001), followed by participants who reported high coffee intake only.
The authors believe that patients interested in reducing skin hyperpigmentation may benefit from increased beverage-based consumption of polyphenols. As study limitations, investigators cited the cross-sectional design, through which causality cannot be established. Additional study with longitudinal follow-up may identify the mechanisms through which polyphenols influence skin photoaging, the investigators wrote.
Fukushima Y, Takahashi Y, Kishimoto Y, et al. Consumption of polyphenols in coffee and green tea alleviates skin photoaging in healthy Japanese women. Clin Cosmet Investig Dermatol. 2020;13:165-172.