Protocol for Pilot Study Testing the Effect of Avocado Consumption on Skin Aging

Abstract

ObjectivesAvocados are an excellent source of bioactive compounds such as monounsaturated fatty acids, sterols, polyhydroxylated fatty alcohols and carotenoids. A common cause of photoaging is exposure to UV light, as the radiation generates oxidative stress, which leads to inflammation and erythema of the skin. Studies have demonstrated that topical application of bioactive compounds from avocado reduce UVB-induced photoaging. Ultraviolet-B (UVB) protection by oral avocado consumption has not been clinically investigated in humans. Therefore, it is the objective of this pilot study to determine if the consumption of one avocado daily for 16 weeks can increase resistance to UVB radiation and reduce skin aging in healthy women. MethodsThis study is a randomized, two arm, parallel group comparison of daily avocado consumption vs. habitual diet. Eligible participants are females, at least 25 years of age, Fitzpatrick Skin type II-IV, in good health with an increased waist circumference of 35 cm. Participants will be excluded if they are habitually eating 2 avocados per month, allergic to avocado and any unstable medical conditions. At screening, informed consent and HIPAA authorization will be reviewed and signed. In addition, Fitzpatrick Skin type and response to UVB will be assessed. Subjects will consume 1 avocado a day (Hass Avocado) or maintain habitual diet (up to 2 avocados/month) daily for 16 weeks. Skin will be assessed at weeks 0, 8 and 16. Minimal erythema dose (MED) will be determined by exposing the inner arm covered by a sleeve with 6 cut out windows with an increasing dose of UVB using the Dermalight 90. Facial melanin index, hydration and sebum will be determined using the mexameter MA18, corneometer CM825 and sebumeter SM815 probes attached to the Cutometer dual MPA 580 (Courage&Khazaka electronic GmbH, Koeln, Germany). 22 participants will be enrolled in each group considering a 10%dropout rate. ResultsPrimary outcome will be the effect of daily avocado consumption on MED assessed by UVB exposure compared to habitual diet. Secondary outcomes will be the effect of daily avocado consumption on facial skin elasticity, sebum, melanin and hydration status as assessed by cutometer compared to habitual diet. ConclusionsThis study is currently recruiting participants. Funding SourcesHass Avocado Board.