Food is the only medicine that the average healthy individual requires on a daily basis. Indeed, more than 2000 years ago, Hippocrates is said to have offered: “Let food be your medicine, and let medicine be your food.”1 It is from such a perspective—that good nutrition is a fundamental building block of good general health and healthy skin—that this discussion proceeds. Specifically, this chapter will focus on some of the key chemical components of a healthy diet that have been shown to confer benefits to the skin. In the process, cutaneous effects will be discussed in the context of vegetarianism, as well as the skin types of the Baumann Skin Typing System. Attention will first be focused on the effects of diet on acne, the most common dermatologic condition, and, finally, on oral supplementation.
There is copious research underway now on the direct effects on health from the consumption or supplementation of various nutrients. A significant proportion of such work focuses specifically on the potential benefits conferred to the skin through the intake of certain foods or supplements. For instance, in 2003, a cross-sectional study of 302 healthy men and women collected data on serum concentrations of nutrients, dietary consumption of nutrients, as well as various cutaneous measurements (including hydration, sebum content, and surface pH), revealing statistically significant relationships between serum vitamin A and cutaneous sebum content as well as surface pH as well as between skin hydration and dietary consumption of total fat, saturated fat, and monosaturated fat. The investigators concluded that such findings are evidence that the condition of the skin can be influenced by alterations in baseline nutritional status.2
Acne vulgaris is one of the most common conditions that prompt visits to a dermatologist. In 1998, it was believed that acne affected as many as 40 to 50 million people in the United States alone.3 More recently, estimates of acne prevalence and incidence in Western populations, while remaining high, have come closer to 17 million in the United States4,5 (see Chapter 15). Interestingly, recent epidemiologic studies in non-Westernized populations (i.e., Inuit, Okinawan Islanders, Ache hunter-gatherers, and Kitavan Islanders) in which acne is rare, indicate that dietary factors, including glycemic load, may play a role in the development of this condition, particularly since incidence of acne has risen in these communities in association with the adoption of Western lifestyles.6–9
Accordingly, Cordain, has argued persuasively for abandoning the traditional belief espoused in the dermatology community since the early 1970s that diet does not contribute to the pathophysiology of acne. In particular, he asserts that the dogma claiming that diet and acne are unrelated has been based on two fundamentally flawed studies from 1969 by Fulton et al. and 1971 by Anderson that lacked control groups, statistical data treatment, as well as blinding and/or placebos and were characterized ...