beta-carotene and Sunburn

Nutritional supplements are increasingly used to protect human skin against environmentally-induced damage, most importantly as a consequence of ultraviolet radiation exposure. beta-carotene is a major constituent of comercially available products administered for systemic photoprotection. Studies on the systemic use of beta-carotene provide evidence that 15-30 mg/d over a period of about 10-12 wk produces a protective effect against UV-induced erythema. Similar effects have been attributed to mixtures of carotenoids or after long-term intake of dietary products rich in carotenoids. Supplementation with carotenoids contributes to basal protection of the skin but is not sufficent to obtain complete protection against severe UV irradiation.

Topics: Administration, Oral; Administration, Topical; Antioxidants; beta Carotene; Dose-Response Relationship, Drug; Drug Administration Schedule; Humans; Nutritional Requirements; Nutritive Value; Skin; Sunburn; Sunlight; Sunscreening Agents

This paper describes the development of the use of carotenoid pigments in the treatment of light-sensitive skin diseases. It also discusses the animal and human studies involved in determining whether carotenoids have any anti-cancer activity. The possible mechanisms of carotenoid photoprotective and anti-cancer actions are briefly discussed.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Adolescent; Adult; Animals; Bacteria; Bacterial Physiological Phenomena; beta Carotene; Canthaxanthin; Carotenoids; Child; Child, Preschool; Diet; Humans; Infant; Light; Neoplasms; Neoplasms, Experimental; Photochemistry; Photosensitivity Disorders; Porphyrias; Protoporphyrins; Skin Diseases; Skin Neoplasms; Sunburn; Sunlight; Ultraviolet Rays

This review deals with topical and systemic approaches for protection of human skin against the harmful effects of solar radiation. Two concerns about the deleterious effects of sun exposure involve: (1) acute effects (e.g., sunburn and drug-induced phototoxicity) and (2) potential long-term risks of repeated sun exposures leading to development of solar elastosis, keratoses, induction of both nonmelanoma and melanoma skin cancer, and alteration of immune responses and functions. Action spectra of normal and abnormal reactions of human skin to acute and chronic effects of solar radiation are presented with a view to helping the physician prescribe the appropriate sunscreens. Factors that influence acute effects of sunburn are reviewed. Various artificial methods effective in minimizing or preventing harmful effects of solar radiation, both in normal individuals and in patients with photosensitivity-related problems, are discussed. Emphasis is placed on the commercially available chemical sunscreens and their properties. Sun protection factor (SPF) values of several brand-name formulations determined with a solar simulator under indoor conditions (laboratory) and with solar radiation under natural, field conditions are presented. Factors responsible for variations of SPF values observed under indoor and outdoor conditions are reviewed. Systemic photoprotective agents and their limitations are outlined. The photobiology of melanin pigmentation (the tanning reaction) is briefly discussed, with emphasis on the dangers of using quick-tanning lotions for stimulation of the tanning reaction.

Topics: 5-Methoxypsoralen; Administration, Oral; Administration, Topical; beta Carotene; Carotenoids; Chloroquine; Dermatitis, Contact; Furocoumarins; Humans; Keratosis; Melanins; Methoxsalen; Nonprescription Drugs; Photosensitivity Disorders; Skin Neoplasms; Skin Pigmentation; Sunburn; Sunscreening Agents; Ultraviolet Rays

Given the public health burden of skin cancer in white populations, an increase in sun protective behavior is needed. In a high-risk community, we assessed long-term sunscreen use among people who had participated in a randomized trial of daily sunscreen application for prevention of skin cancer.. In 1992, 1621 residents of the subtropical Australian township of Nambour were randomly allocated to either daily or discretionary sunscreen use until 1996. From 1997 to 2002, we monitored by questionnaires their ongoing sunscreen use.. People who had never or irregularly used sunscreen when in summer sun before the trial were more likely (P < 0.0001) to be sustaining regular application especially to their face (20% vs. 11%) and forearms (14% vs. 5%) if they had been allocated to daily, not discretionary, use of sunscreen for 5 years.. Regular voluntary sunscreen use for skin cancer prevention can be sustained by sun-sensitive people in the long term. Habit formation appears to be an important goal for sun protection programs among those living, or on vacation, in sunny places.

Topics: Adult; Aged; Analysis of Variance; Australia; beta Carotene; Follow-Up Studies; Health Behavior; Humans; Middle Aged; Skin Neoplasms; Sunburn; Sunscreening Agents; Surveys and Questionnaires; Vitamins

Beta-carotene, a quencher of excited species such as singlet oxygen and free radicals, has been reported to protect against cutaneous photodamage, including sunburn acutely and photocarcinogenesis chronically. The present double blind placebo-controlled study examines the effect of beta-carotene supplementation on the human sunburn response and specifically on the induction of sunburn cells at the time of peak reaction intensity (24 h) after a single solar simulated light exposure 3 times the individually determined minimal erythema dose (MED). Administered orally either as a single 120 mg dose to dietarily restricted subjects or for 23 d as a daily 90 mg supplement to subjects on standard diets, beta-carotene increased plasma and skin levels of beta-carotene compared to both pretreatment levels and placebo-treated controls, but provided no clinically or histologically detectable protection against a 3 MED sunburn reaction. Thus, these data suggest that oral beta-carotene supplementation is unlikely to modify the severity of cutaneous photodamage in normal individuals to a clinically meaningful degree.

Topics: Aged; Apoptosis; beta Carotene; Carotenoids; Diet; DNA Damage; Double-Blind Method; Female; Free Radical Scavengers; Humans; Keratinocytes; Radiation-Protective Agents; Sunburn

Plasma concentrations of beta-carotene were determined in healthy men ingesting 180 mg beta-carotene/d during studies on the effects of beta-carotene on sunburn prevention. This dose is also used in the treatment of light-sensitive skin diseases. beta-carotene concentrations were found to reach a plateau in 1.5 to 4 wk, although there was much individual variation in the actual serum concentrations achieved. Carotenodermia was present in most subjects. No evidence of toxicity was found, confirming the findings of previous photosensitivity-prevention studies, which also reported no significant toxicity attributable to beta-carotene.

Topics: Adult; beta Carotene; Carotenoids; Humans; Intestinal Absorption; Male; Randomized Controlled Trials as Topic; Sunburn

Reactive free radicals can be produced in the skin by the action of environmental factors, such as sun radiation and toxins. These radicals can damage the DNA, proteins and lipids of the living cells. The consequences can be skin aging, immune suppression and even skin cancer. Humans have developed a protective mechanism against the action of free radicals in the form of antioxidant substances. Several of these antioxidants cannot be produced by humans and have to be acquired via food, such as carotenoids. Optical, non-invasive methods, like resonance Raman spectroscopy, allow a qualitative and quantitative online detection of the kinetics of antioxidants such as carotenoids in the skin. By employing this method it has been shown that the uptake of carotenoids in food can lead to an accumulation in the skin. On the other hand, stress, illness and UV-radiation can reduce the concentration of antioxidant substances in the skin. A high concentration of antioxidant substances is protective and associated with a reduction in skin wrinkling.

Topics: Antioxidants; beta Carotene; Beverages; Biological Availability; Carotenoids; Dermatitis, Contact; Food; Humans; Lycopene; Nutritive Value; Signal Processing, Computer-Assisted; Skin Aging; Skin Physiological Phenomena; Spectrum Analysis, Raman; Sunburn; Ultraviolet Rays; Vegetables

Topics: Bacteriorhodopsins; beta Carotene; Carotenoids; Child; Female; Humans; Photosensitivity Disorders; Radiation-Protective Agents; Rhodobacter sphaeroides; Sunburn; Sunlight