Nutritional Clinical Studies in Dermatology

October 2013 | Volume 12 | Issue 10 | Original Article | 1104 | Copyright © October 2013


Aikaterini I. Liakou MD,a Michael J. Theodorakis MD,b Bodo C. Melnik MD PhD,c
Apostolos Pappas PhD,d and Christos C. Zouboulis MD PhDa

aDepartments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Dessau, Germany
bUniversity of Athens Medical School, Athens, Greece
cDepartment of Dermatology, Environmental Medicine and Health Theory, University of Osnabrück, Germany
dThe Johnson & Johnson Skin Research Center, CPPW, a division of Johnson & Johnson Consumer Companies, Inc., Skillman, NJ

Abstract
BACKGROUND & AIMS: Nutrition has long been associated with skin health, beauty, integrity and aging through multiple pathways and cofactors implicated in skin biology. The onset and clinical course of various common skin diseases, especially acne, psoriasis, atopic dermatitis, and hair loss, have been suggested to be critically affected by nutrition patterns and habits. The relationship between acne and diet, predominantly the role of high glycemic load diets and dairy consumption have recently gained increased interest. Abnormal nutritional conditions such as obesity or malnutrition often manifest themselves by specific cutaneous features and altered skin function. Skin photoprotection, rendered by various nutrients, is well documented and appropriate nutritional supplementation has been shown to exert beneficial effects upon impaired skin integrity, restore its appearance and promote skin health. It is our intention to provide a comprehensive review of the most recent information on the role of nutrition for common skin diseases and regulation of skin biology.
METHODS: Nutritional clinical studies in dermatology have been reviewed using the MedLine literature source and the terms "diet" or "nutrition" and "skin".
RESULTS & CONCLUSIONS: The data on the relationship between nutrition and skin are until now controversial and much more work is needed to be done to clarify possible etiological correlations.

J Drugs Dermatol. 2013;12(10):1104-1109.

INTRODUCTION

The structural integrity, functional capacity, and regenerative potential of the human skin are known to be influenced, to a variable extent, by a plethora of factors, which thus greatly affect our appreciation of its overall appearance and our perception of its health and beauty. Heredity, sunlight, environmental or occupational exposure, chronic disease, medications, drug abuse, dietary habits, hormonal supplementation, psychosomatic stress, and poor socioeconomic conditions have all been implicated in the pathophysiology of skin abnormalities and aging. Nutrition has historically been one of the earliest and most important factors associated with skin health. However, the degree of its impact upon skin physiology, as well as the mechanisms involved in various nutrition-dependent alterations in skin structure and function, remain highly controversial.
Practical hardships in explicitly establishing a causative association between consumption of specific nutrients or food products and their potential effects on the skin have been hampered within clinical research, even when this relationship might appear straightforward or highly reasonable.
In this article, we thoroughly analyze available evidence derived from the most important clinical nutritional studies with regard to the human skin and we provide scientifically sound and clinically relevant conclusions based on emerging knowledge in this very challenging area of research.

Effects of Nutrition on Specific Skin Diseases

Nutrition and acne
Historically, the association between acne and nutrition has been highly controversial. The studies of Fulton et al,1 in 1969 and Anderson2 in 1971 failed, at the beginning of the second half of the century, to show any associations between diet and acne. The former,1 was a cross-over subject-blind interventional study of 65 adolescents who received either a chocolate bar or a control bar with similar amounts of sugar and fat in both bars; all subjects exhibited a similar glycemic index and glycemic load. The latter,2 a case series study of 27 students did not show any effects of various foods (chocolate, milk, toasted peanuts or cola) during a short study period of only 1 week.
The first serious randomized placebo-controlled dietary study was provided by Smith et al,3 who demonstrated a link between high glycemic load carbohydrate intake and acne. Smith et al,3 demonstrated significant improvement of acne severity in 23 Australian males aged between 15-25 years, adhering to a low glycemic load diet. The low glycemic load diet resulted in significant reduction in weight, body mass index, free androgen index, and increased IGF binding protein-1 (IGFBP-1) serum