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Open Access Research

Chocolate flavanols and skin photoprotection: a parallel, double-blind, randomized clinical trial

Jaime Andres Mogollon1, Catherine Boivin2, Simone Lemieux3, Claudine Blanchet1, Joël Claveau2 and Sylvie Dodin14*

Author Affiliations

1 St. François d’Assise Hospital, Centre hospitalier universitaire de Québec (CHUQ), Quebec, QC, Canada

2 Melanoma and Skin Cancer Clinic, Dermatology Division, Hôtel-Dieu Hospital, CHUQ, Quebec, QC, Canada

3 Department of Food Sciences and Nutrition, Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec, QC, Canada

4 Department of Obstetrics and Gynecology, Research Centre, St. François d’Assise Hospital (CHUQ), Université Laval, Quebec, QC G1L 3 L5, Canada

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Nutrition Journal 2014, 13:66  doi:10.1186/1475-2891-13-66

Published: 27 June 2014

Abstract

Background

Solar ultraviolet (UV) radiation has deleterious effects on the skin, including sunburn, photoaging and cancer. Chocolate flavanols are naturally-occurring antioxidant and anti-inflammatory molecules that could play a role in preventing cutaneous UV damage. We investigated the influence of 12-week high-flavanol chocolate (HFC) consumption on skin sensitivity to UV radiation, measured by minimal erythema dose (MED). We also evaluated skin elasticity and hydration.

Methods

In this 2-group, parallel, double-blind, randomized controlled trial, 74 women aged 20–65 years and Fitzpatrick skin phototypes I or II were recruited from the general community in Quebec City, for randomization to either HFC (n = 33) or low-flavanol chocolate (LFC) (n = 41). A blocked randomisation (4), considering date of entry, skin type and age as factors, generated a sequentially-numbered allocation list. Study participants and research assistants were blinded. Totally, 30 g of chocolate were consumed daily for 12 weeks, followed by a 3-week washout period. MED was assessed at baseline and at 6, 9, 12 and 15 weeks. Main outcome was changes in MED at week 12.

Results

33 participants in the HFC group and 41 in the LFC group were analyzed with 15 weeks of follow-up. Both groups showed similarly-increased MED at 12 weeks (HFC: 0.0252 ± 0.1099 J/cm2 [mean ± standard deviation (SD)]; LFC: 0.0151 ± 0.1118; mean difference (MD): 0.0100 J/cm2; 95% confidence interval (CI): -0.0417 to 0.0618). However, after 3-week washout, the HFC group presented decreased MED (-0.0248 ± 0.1145) whereas no effect was seen in the LFC group (0.0168 ± 0.1698) (MD: -0.0417; 95% CI: -0.1106 to 0.0272). Net temple elasticity increased slightly but significantly by 0.09 ± 0.12 mm in the HFC group at 12 weeks compared to 0.02 ± 0.12 mm in the LFC group (MD: 0.06; 95% CI: 0.01 to 0.12 ). No significant adverse events were reported.

Conclusion

Our study failed to demonstrate a statistically-significant protective effect of HFC vs. LFC consumption on skin sensitivity to UV radiation as measured by MED.

Trial registration

ClinicalTrials.gov identifier: NCT01444625

Keywords:
Skin photoprotection; Flavanols; Chocolate; Cocoa; Minimal erythema dose