Almond consumption increased UVB resistance in healthy Asian women

Abstract

Background: Almonds are a rich source of phenolic and polyphenolic compounds, which have antioxidant activity. In vitro and in vivo studies have demonstrated that topical application of almond oil and almond skin extract reduces UVB-induced photoaging. Ultraviolet-B (UVB) protection by oral almond consumption has not been previously studied in humans.

Objectives: To investigate whether oral almond consumption can increase resistance to UVB radiation and reduce skin aging in healthy Asian women.

Methods: Thirty-nine female participants (18-45 years) with Fitzpatrick skin type II-IV were randomly assigned to consume either 1.5 oz of almonds or 1.8 oz of pretzels daily for 12 weeks. Minimal erythema dose (MED) was determined using a standardized protocol, which determined the minimal radiation needed to induce erythema on the inner arm following UVB exposure. Facial skin texture was evaluated by two dermatologists using the Clinician's Erythema Assessment scale and Allergan Roughness scale. Facial melanin index, hydration, sebum, and erythema were determined using a cutometer.

Results: The MED was increased in the subjects consuming almonds compared to the control group consuming pretzels. There were no differences noted between the groups consuming almonds versus pretzels in Allergan roughness, melanin, hydration, or sebum on facial skin.

Conclusions: Our findings suggest that daily oral almond consumption may lead to enhanced protection from UV photodamage by increasing the MED.

Keywords: UVB skin exposure; almond; facial skin texture; minimal erythema dose; randomized controlled trial.

FIGURE 1

Minimal erythema dose in healthy Asian women consuming almond or pretzels for 12 weeks. Data are means ± SD. *compared to baseline (P ≤ .05); p‐value indicates comparison between almond and pretzel group; almond N = 13, pretzel N = 16

FIGURE 2

Effect of almond consumption on facial erythema and Allergan roughness compared to pretzel consumption at baseline and week 12. Data are means ± SD; almond N = 13, pretzel N = 16