Clinical trial NCT01032031: The Effect of Green Tea and Vitamin C on Skin Health
Official title: The Effect of Dietary Bioactive Compounds on Skin Health in Humans in Vivo
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Skin Cancer
Keywords: Green tea
Vitamin C
Ultraviolet radiation
Inflammation
Photoageing
Lead sponsor: University of Manchester
Sponsor class: OTHER
Collaborators: name: University of Leeds
name: University of Bradford
First posted: 2009-12-15
Enrollment: 95
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

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.

Eligibility criteria: 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

Primary outcomes:
measure: Change in the minimum erythemal dose (MED) of ultraviolet radiation.
timeFrame: 3 months
Secondary outcomes:
measure: Intergroup comparison of inflammatory mediators (cytokines/chemokines) in skin biopsy sections and blister fluid.
timeFrame: 3 months
measure: Intergroup comparison of histological biomarkers (leucocytes, markers of photoageing, DNA damage) in skin biopsy sections.
timeFrame: 3 months
measure: Nutrient (polyphenol) bioavailability in samples of skin, blood and urine.
timeFrame: 3 months
Other outcomes:
Locations:
city: Manchester
country: United Kingdom
facility: Salford Royal NHS Foundation Trust
Study officials:
affiliation: University of Manchester
name: Lesley E Rhodes, MBBS, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Rhodes LE, Darby G, Massey KA, Clarke KA, Dew TP, Farrar MD, Bennett S, Watson RE, Williamson G, Nicolaou A. Oral green tea catechin metabolites are incorporated into human skin and protect against UV radiation-induced cutaneous inflammation in association with reduced production of pro-inflammatory eicosanoid 12-hydroxyeicosatetraenoic acid. Br J Nutr. 2013 Sep 14;110(5):891-900. doi: 10.1017/S0007114512006071. Epub 2013 Jan 28.
citation: Farrar MD, Nicolaou A, Clarke KA, Mason S, Massey KA, Dew TP, Watson RE, Williamson G, Rhodes LE. A randomized controlled trial of green tea catechins in protection against ultraviolet radiation-induced cutaneous inflammation. Am J Clin Nutr. 2015 Sep;102(3):608-15. doi: 10.3945/ajcn.115.107995. Epub 2015 Jul 15.
citation: Clarke KA, Dew TP, Watson RE, Farrar MD, Osman JE, Nicolaou A, Rhodes LE, Williamson G. Green tea catechins and their metabolites in human skin before and after exposure to ultraviolet radiation. J Nutr Biochem. 2016 Jan;27:203-10. doi: 10.1016/j.jnutbio.2015.09.001. Epub 2015 Sep 12.
citation: Clarke KA, Dew TP, Watson RE, Farrar MD, Bennett S, Nicolaou A, Rhodes LE, Williamson G. High performance liquid chromatography tandem mass spectrometry dual extraction method for identification of green tea catechin metabolites excreted in human urine. J Chromatogr B Analyt Technol Biomed Life Sci. 2014 Dec 1;972:29-37. doi: 10.1016/j.jchromb.2014.09.035. Epub 2014 Sep 30.