Whole-Food, Plant-Based Diet
A whole-food, plant-based (WFPB) diet is another popular dietary approach that consists of eating fruits, vegetables, legumes, nuts, seeds, and grains in their whole natural form.94 This diet discourages all animal products, including red meat, seafood, dairy, and eggs. It is similar to a vegan diet except that it eliminates all highly refined carbohydrates, vegetable oils, and other processed foods.94 Randomized clinical studies have demonstrated the WFPB diet to be effective in the treatment of obesity and metabolic syndrome.95,96
A WFPB diet has been shown to increase the antioxidant capacity of cells, lengthen telomeres, and reduce formation of advanced glycation end products.94,97,98 These benefits may help combat accelerated skin aging, including increased skin permeability, reduced elasticity and hydration, decreased angiogenesis, impaired immune function, and decreased vitamin D synthesis. Accelerated skin aging can result in delayed wound healing and susceptibility to skin tears and ecchymoses and also may promote the development of cutaneous malignancies.99 There remains a lack of clinical data studying a properly formulated WFPB diet in the dermatologic setting.
The paleolithic (Paleo) diet is an increasingly popular way of eating that attempts to mirror what our ancestors may have consumed between 10,000 and 2.5 million years ago.100 It is similar to the Mediterranean diet but excludes grains, dairy, legumes, and nightshade vegetables. It also calls for elimination of highly processed sugars and oils as well as chemical food additives and preservatives. There is a strict variation of the diet for individuals with autoimmune disease that also excludes eggs, nuts, and seeds, as these can be inflammatory or immunogenic in some patients.100-106 Other variations of the diet exist, including the ketogenic Paleo diet, pegan (Paleo vegan) diet, and lacto-Paleo diet.100 An often cited criticism of the Paleo diet is the low intake of calcium and risk for osteoporosis; however, consumption of calcium-rich foods or a calcium supplement can address this concern.107
Although small clinical studies have found the Paleo diet to be beneficial for various autoimmune diseases, clinical data evaluating the utility of the diet for cutaneous disease is lacking.108,109 Numerous randomized trials have demonstrated the Paleo diet to be effective for weight loss and improving insulin sensitivity and lipid levels.110-116 Thus, the Paleo diet may theoretically serve as a viable adjunct dietary approach to the treatment of cutaneous diseases associated with obesity and metabolic derangement.117
Arguably the most controversial and radical diet is the carnivore diet. As the name implies, the carnivore diet is based on consuming solely animal products. A properly structured carnivore diet emphasizes a “nose-to-tail” eating approach where all parts of the animal including the muscle meats, organs, and fat are consumed. Proponents of the diet cite anthropologic evidence from fossil-stable carbon-13/carbon-12 isotope analyses, craniodental features, and numerous other adaptations that indicate increased consumption of meat during human evolution.118-122 Notably, many early humans ate a carnivore diet, but life span was very short at this time, suggesting the diet may not be as beneficial as has been suggested.
Despite the abundance of anecdotal evidence supporting its use for a variety of chronic conditions, including cutaneous autoimmune disease, there is a virtual absence of high-quality research on the carnivore diet.123-125
The purported benefits of the carnivore diet may be attributed to the consumption of organ meats that contain highly bioavailable essential vitamins and minerals, such as iron, zinc, copper, selenium, thiamine, niacin, folate, vitamin B6, vitamin B12, vitamin A, vitamin D, vitamin K, and choline.126-128 Other dietary compounds that have demonstrated benefit for skin health and are predominantly found in animal foods include carnosine, carnitine, creatine, taurine, coenzyme Q10, and collagen.129-134 Nevertheless, there is no data to recommend the elimination of antioxidant- and micronutrient-dense plant-based foods. Rigorous clinical research evaluating the efficacy and safety of the carnivore diet in dermatologic patients is needed. A carnivore diet should not be undertaken without the assistance of a dietician who can ensure adequate micronutrient and macronutrient support.
The adjunctive role of diet in the treatment of skin disease is expanding and becoming more widely accepted among dermatologists. Unfortunately, there remains a lack of randomized controlled trials confirming the efficacy of various dietary interventions in the dermatologic setting. Although evidence-based dietary recommendations currently are limited, it is important for dermatologists to be aware of the varied and nuanced dietary interventions employed by patients.
Ultimately, dietary recommendations must be personalized, considering a patient’s comorbidities, personal beliefs and preferences, and nutrigenetics. The emerging field of dermatonutrigenomics—the study of how dietary compounds interact with one’s genes to influence skin health—may allow for precise dietary recommendations to be made in dermatologic practice. Direct-to-consumer genetic tests targeted toward dermatology patients are already on the market, but their clinical utility awaits validation.1 Because nutritional science is a constantly evolving field, becoming familiar with these popular diets will serve both dermatologists and their patients well.