Skin Cancer
Conditions
Keywords
Green tea, Vitamin C, Ultraviolet radiation, Inflammation, Photoageing
Brief summary
There is little information on the effect of oral bioactive compounds on human skin clinically despite evidence of a beneficial effect from laboratory studies. The aim of this study is to examine the effect of oral bioactive compounds (green tea and vitamin C) on the health of human skin by measuring markers of skin health directly and skin nutrient uptake.
Detailed description
There is little information on the effect of oral catechin, a nutritionally relevant bioactive compound, on skin health in humans in vivo despite considerable evidence for protective effects in experimental studies. Vitamin C is essential for skin health and stabilises catechins in the gut lumen. Ultraviolet radiation (UVR) in sunlight is a key environmental stressor impacting on skin health. Effects include acute inflammation and longer term photodamage. OBJECTIVE: To examine the protective effect of catechin and vitamin C on UVR-induced inflammation. STUDY DESIGN (1) A double-blind randomised controlled nutritional study in 50 healthy volunteers. Volunteers will receive 3 months dietary supplement with high dose bioactive (n=25),or placebo (n=25). The aim is to quantify the influence of catechin/vitamin C on: 1. UVR-induced inflammation 2. Leukocyte infiltration 3. Inflammatory mediators 4. Markers of photoageing 5. DNA damage 6. Bioavailability will also be assessed (2) Bioavailability of catechin and vitamin C in skin and blood. Volunteers will receive active dietary supplement. Blood and urine samples will be taken over a period of 6 hours to determine blood bioavailability. Skin biopsies will also be taken to assess skin bioavailability. Volunteers will then receive 3 months of active dietary supplement followed by repeated sampling.
Interventions
DIETARY_SUPPLEMENTGreen tea + vitamin C high dose
One green tea capsule (1250mg catechin) and one vitamin C tablet (100mg) daily for 3 months
DIETARY_SUPPLEMENTPlacebo capsule
One capsule daily for 3 months
Sponsors
University of Leeds
University of Bradford
University of Manchester
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy adults * Sun-reactive skin type I / II
Exclusion criteria
* History of skin cancer * History of a photosensitivity disorder * History of a generalised skin disorder * Sunbathing (including sunbeds) in the past 3 months * Pregnancy * Taking photoactive medicine * Drink tea \> 2 cups/day * Taking nutritional supplements
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in the minimum erythemal dose (MED) of ultraviolet radiation. | 3 months | The UV minimum erythemal dose (MED) will be determined for each study volunteer before and after nutritional supplementation to examine if the intervention can increase the MED and therefore protect against UV-induced erythema. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Intergroup comparison of inflammatory mediators (cytokines/chemokines) in skin biopsy sections and blister fluid. | 3 months | — |
| Intergroup comparison of histological biomarkers (leucocytes, markers of photoageing, DNA damage) in skin biopsy sections. | 3 months | — |
| Nutrient (polyphenol) bioavailability in samples of skin, blood and urine. | 3 months | Bioavailability will be assessed in volunteers participating in both the first (RCT) and second (non-randomised bioavailability) parts of the study. |
Countries
United Kingdom
Outcome results
None listed