(P11-036-25) Study Protocol: Effects of Polyphenol-Rich Pulses in Daily Diet on Skin Health, Inflammation, and the Cutaneous Microbiome and Lipids in Women

Objectives: We hypothesize that adding a daily serving of cooked mixed pulses (lentils, red kidney beans, black beans, and pinto beans) to the diet will improve skin health in women aged 45–65 by reshaping the cutaneous microbiome and lipids.

Methods: This randomized, controlled, parallel design trial (NCT06538415) will enroll 48 healthy women aged 45–65 with Fitzpatrick skin type 2 or 3. After a 3-week run-in period, participants will be stratified by menopausal status and skin type and randomized to receive either mixed pulses or a control white rice diet matched for calories and macronutrients. Participants will consume their assigned diet daily for 14 weeks (Day 0–Day 99) and adhere to dietary and skincare restrictions, avoiding other pulses, polyphenol-rich foods, supplements, and anti-aging skincare products. During the final run-in week, UVB phototherapy will determine the minimal erythema dose (MED) on the medial lower back. Visits 2–4 (Days 0–1, 49–50, and 99–100) will include fasting blood draws to analyze oxidative stress and inflammation biomarkers, anthropometric measurements, dietary and skincare surveys, and comprehensive skin testing. On the first day of each visit, participants will receive 2x MED UVB exposure on their back and return 24 hours later for a series of skin assessments. This will include a Visioscan VC20+ for wrinkles, roughness, scaliness, and smoothness; a Cutometer for elasticity; and a Tewameter, Corneometer, and Skin-pH Meter for transepidermal water loss, hydration, and pH, respectively. Erythema, melanin index, and skin color will be evaluated with a Mexameter and Colorimeter, and skin testing will conclude with cutaneous microbiota and epidermal lipid sampling. 

Results: N/A

Conclusions: We expect pulse consumption to reduce wrinkles, UV-induced erythema, transepidermal water loss, oxidative stress, and inflammation, while improving skin elasticity. Microbiota and lipid analyses are expected to uncover key mediators driving the observed benefits of pulse consumption on skin health.

Funding Sources: This research is supported by the Pulse Crop Health Initiative through the USDA Agricultural Research Service.