Adding Polyphenol-rich Pulses to Daily Diet Improves Skin Health by Reshaping the Skin Microbiome

Not Applicable

Not yet recruiting

• Conditions: Healthy
• Interventions: Other: Pulse Diet; Other: Control Rice Diet

• Registration Number: NCT06538415
• Lead Sponsor: University of Florida

Brief Summary

Skin health is influenced by the microbiome, lipids, oxidative stress, inflammation, and UV exposure. A 14-week trial with 50 women aged 45-65 will test if polyphenol-rich pulses improve skin health by affecting these factors. Using a white rice control diet, the study will measure skin parameters and analyze correlations with changes in lipids and microbiome, potentially proving the benefits of pulses.

Detailed Description

Human skin is the largest organ in the body. The slow deterioration of skin appearance and its barrier function are the most prominent signs of human ageing. Cutaneous factors (microbiome and lipids) have immediate and direct impacts on skin health and functions. Intrinsic factors (oxidative stress and inflammation) and extrinsic ones (mostly UV irritation due to sun exposure) affect the skin chronically. Our preliminary research showed that six weeks of cranberry juice intake improved part of women's skin health parameters and decreased oxidative stress. Its activities on the skin correlated with changes in skin microbiome and epidermal lipids. Pulses, especially lentils and beans, are rich sources of polyphenols and fibers. However, there is no clinical evidence on whether adding a serving of cooked mixed pulses with high polyphenol content (lentils, red kidney bean, black beans, and pinto beans) to the diet affects skin health and the underlying causes of skin aging. Women make over 90% of the decisions on food purchases for their families. Skin health is a major concern for women because skin aging becomes visibly noticeable after age 30. The investigators hypothesize that polyphenol-rich pulses improve skin health by reshaping the cutaneous microbiome and lipids and suppressing inflammation and oxidative stress. This hypothesis will be tested in a 14-week clinical trial in 50 women aged 45-65 using a randomized controlled parallel design. The control diet will be formulated using white rice to match the calories and macronutrients of mixed pulses.

Study Timeline

• Study First Submitted: 2024-07-26
• Study First Submitted QC: 2024-08-02
• Study First Posted: 2024-08-05
• Status Verified: 2025-01
• Last Update Submitted: 2025-01-02
• Last Update Posted: 2025-01-03
• Study Start: 2025-03-01
• Primary Completion: 2026-09-01
• Study Completion: 2026-09-01

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: Female
• Target Recruitment: 50

Inclusion Criteria

• BMI (18.5-29.9)
• Body weight ≥110 pounds
• Fitzpatrick skin type 2 and 3.

Exclusion Criteria

• pregnancy
• breast-feeding
• impaired fasting glucose
• frequent alcohol use
• history of skin cancer
• sunbathing and the use of tanning bed, intake of vitamin/mineral supplements
• habitual high intake of fruits (≥ 2 cups daily)
• intake of medication that might influence the outcome of the study

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Pulse Diet	Pulse Diet	Participants will consume cooked pulse (112 calories -lentils, red kidney beans, black beans, and pinto beans) during 14 weeks.
Control Rice Diet	Control Rice Diet	Participants will consume cooked rice (112 calories) during 14 weeks.

Primary Outcome Measures

Name	Time	Method
Change from baseline skin transepidermal water loss	100 days	Skin transepidermal water loss will be measured using a Tewameter to evaluate the water barrier function of the skin. The Tewameter measures the density gradient of the water evaporation from the skin (g/h/m\^2).
Change from baseline skin erythema and melanin index	100 days	Skin erythema and melanin index ((Arbitrary Mexameter Units on a scale of 0-999) will be assessed with Mexameter. These two components are mainly responsible for the color of the skin. They are measured by reflectance.
Change in skin microbiome	100 days	For skin swabbing, a 3x3-cm square on a forearm will be swabbed with a cotton swab soaked in 0.9% sodium chloride with 0.1% Tween-20 in a Z-stroke manner
Change in inflammation	100 days	* Plasma concentration levels (pg/mL) of IL-6 proteins will be analyzed as inflammation biomarkers using ELISA kits.; * Plasma concentration levels (mg/mL) of C-reactive proteins will be analyzed as inflammation biomarkers using ELISA kits.
Change from baseline Skin color after UV radiation	100 days	Irradiation will be applied to dorsal skin (back, scapular region not typically exposed to the sun) with 2 times of minimal erythema dose using an FDA approved UVB phototherapy light and a UV light meter. At baseline, after 56 and 112 days, skin color will be measured before and 24 hours after irradiation. Skin color will be evaluated by a colorimeter using the 3-dimensional color system with L\*, a\*, and b\*-values. L\* and b\* values assess lightness and browning effects, respectively. The a\*-value (red/green-axis) is a measure for reddening (erythema).
Change from baseline skin pH plus	100 days	Skin pH will be measured using a Skin-pH-Meter.
Change from baseline skin hydration	100 days	Skin hydration (Arbitrary Units (AU) on a scale of 0-120) will be measured using a Skin Corneometer.
Change in oxidative stress	100 days	Concentration of Malondialdehyde (nmol/mL) in plasma will be determined as a marker of lipid peroxidation using a photometric method.