UC Davis

The role of nutrition in dermatology has been investigated for a long time, with a history of research focused on the effects of nutritional disorders on the skin. Some classic examples include pellagra, scurvy, and acrodermatitis enteropathica. Although these conditions have been mainly eradicated from developed countries due to fortification of food with the essential nutrients of concern or supplementation upon early detection, they can still be found among individuals or communities who are not receiving adequate nutrition due to factors such as economic instability, alcoholism, or eating disorders. As skin diseases caused by nutrition deficiencies become under control, current research focuses on managing dermal disorders such as dermatitis and acne, or promoting esthetics by decreasing wrinkles and hyperpigmentation as well as increasing hydration, collagen, and elasticity. Epidemiological studies suggest that a diet pattern rich in plant-based foods such as fruits and vegetables is associated with improved skin esthetics, such as fewer wrinkles, and lowers the risk of dermatological disorders. Plant-based foods are typically rich in bioactive compounds such as carotenoids, vitamins, and polyphenols that provide oxidant defense, protect against DNA damage and promote structural integrity to the skin. Deficiencies of select micronutrients such as vitamin A, C, E, and K have also been associated with certain skin disorders such as thickening of the skin, poor wound healing, and dermatitis. Unlike health conditions such as cardiovascular disease and diabetes, official dietary recommendations for specific skin disorders or esthetic concerns do not currently exist. The 2020 – 2025 Dietary Guidelines for Americans recommend consuming whole fruits and a variety of vegetables, with specific reference amounts for those with dark green, red, and orange colors, which are typically rich in carotenoids. This general recommendation aligns with the epidemiological studies that suggest beneficial effects to the skin by adopting a dietary pattern that consists of more plant-based foods. However, each fruit and vegetable has a unique nutrition profile and may elicit different skin benefits. This dissertation aimed to explore and understand the benefits of different plant-based food consumption on the skin. A particular emphasis was placed on mango, a tropical fruit that is widely consumed, and its relation to skin and inflammation. Chapter I provides some historical background on nutrition and skin, contextual information on the structure and functions of the skin, as well as a literature review of the reported effects of dietary carotenoids, vitamins, and polyphenols that can be found in mango on skin health and their potential mechanisms. The promising effects of mango intake led to the development of a study as detailed in Chapter II, which is a published manuscript that reported on a clinical trial that investigated the effects of fresh-frozen mango fruit intake on facial wrinkles in the lateral canthi and erythema in the cheeks of postmenopausal women with fair to beige skin tones. Chapter III is a manuscript that will be submitted for publication that reviewed the current evidence for consumption of plant-based foods and extracts, including fruits, vegetables, nuts, and legumes, on skin protection assessing parameters related to collagen, elasticity, erythema, hydration, roughness, and wrinkle. The narrative review focused on clinical dietary interventions with an aim to enable dietitians to provide better dietary recommendations with regards to select dermatological concerns. Chapter IV discussed the role of inflammatory markers on cardiovascular health and describes a study that investigated the effects of mango intake on endothelial function and pro-inflammatory markers. Appendix A is an accepted manuscript that described the development, utilization, and efficiency of a nutrition education game that aimed to elicit and reinforce healthier snack choices in children aged 9 to 13 years old. Appendix B details a newly funded proposed study to investigate the effects of mango intake on wrinkles and other skin measurements and changes in the gut microbiome by comparing it to a control group. In part, to confirm the findings from the study reported in Chapter II as the lack of a control group was a major limitation. Finally, a summary of this work and a discussion on future research directions will be presented in the Perspectives and Conclusions section.