Location: Small Grain and Food Crops Quality Research
Project Number: 3060-21650-002-062-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 15, 2024
End Date: Dec 31, 2025
Objective:
The primary objective is to determine whether a serving of cooked mixed pulses (lentils, red kidney beans, black beans, pinto beans, 22 g each) daily for 16 weeks positively affects skin health parameters, including UV-induced skin erythema, wrinkles, smoothness, roughness, elasticity, hydration, transepidermal water loss (a skin barrier index), and skin pigments on the face and forearm in women 45-65. The secondary objective is to determine whether the intake of cooked mixed pulses modulates skin microbiome and epidermal lipids and reduces inflammation and oxidative stresses in women compared to a rice-based control diet.
Approach:
Lentils and dry beans are rich sources of polyphenols and dietary fibers; however, they are not consumed as a daily diet in America. This research will provide clinical evidence on whether daily consumption of mixed pulses protects skin health by reshaping the cutaneous microbiome and lipids and reducing inflammation and oxidative stress. A randomized, controlled, parallel design will be used. A basic skincare routine will be allowed, but anti-aging and anti-wrinkling products will be restricted. Participants will maintain dietary and skin care restrictions during the 3-week run-in period and the following 16 weeks. During the 3rd week of the run-in period, participants will come to the lab (V1) to test minimal erythema dose using an FFDA-approved UVB phototherapy light 19.
After the run-in period, participants will be randomly assigned to pulse and control groups using stratified block randomization for comparable age and skin type distribution 20.
Twenty-four hours before the lab visits (V2-V4), participants will stop by the lab to receive UV irradiation on dorsal skin using two times minimal erythema dose. On the next day, after confirming compliance with the study protocol, a fasting blood sample will be drawn by a phlebotomist. Body weight, height, and waist circumference will be recorded. After eating the assigned test diet as breakfast with a cup of water, participants will complete a skin care survey and ASA24 dietary record before skin tests. Participants will be advised to maintain their normal daily life but avoid excessive sun exposure (e.g., sunbathing or on the beach for over 30 min) one week before skin testing. Subjects will be requested to stop using any skin care products 24 hours prior to skin testing. Participants may resume their use of skin care products after skin tests are done. Participants' compliance will be assessed using compliance calendars, skincare, and dietary assessments. Mixed pulses are expected to reduce wrinkles, UV-induced erythema, and skin transepidermal water loss but improve skin elasticity. We also anticipate pulse consumption will reduce inflammation and oxidative stress compared to the control diet. Sixteen weeks of pulse consumption is expected to have greater activities than eight weeks. We predict that pulses modulate both skin microbiome and epidermal lipids. Due to the critical role of the skin microbiome and lipids, we expect to identify skin microbes and lipids that partially mediate the beneficial effects of pulse consumption on skin health.
