The mechanism of action and clinical benefits of soy for the treatment of hyperpigmentation.

BACKGROUND: Hyperpigmentation disorders are common and diverse conditions that may require treatment for medical and/or cosmetic reasons. Hyperpigmented lesions can reduce patients' quality of life, self-perception, and social and vocational functioning. The most commonly used treatments for hyperpigmentation include topical agents, such as hydroquinone, retinoids and azelaic acid.
OBJECTIVES: Current topical treatments have significant limitations; they often do not produce adequate results and may be limited by adverse effects, such as dermatitis. Soy and soy-based products have demonstrated a wide range of potential benefits for health and nutrition, including a range of dermatological effects.
METHODS: Research from the last decade has identified multiple mechanisms by which soy-derived products may affect skin pigmentation, as well as photodamage and photoaging, overall skin health, and even the risk for and progression of skin cancer.
RESULTS: Preclinical evidence has demonstrated that soy-derived serine protease inhibitors affect skin pigmentation by inhibiting protease-activated receptor-2-mediated phagocytosis of melanosomes by keratinocytes.
CONCLUSION: Soy-based products containing these serine protease inhibitors may represent a new therapeutic option for dermatological treatment. Indeed, recent evidence from randomized clinical studies supports the safe and effective use of soy products for the treatment of hyperpigmentation.