oxidants and antioxidants in biology - Oxygen Club of California

Lipophilic micronutrients and sun protection
W. STAHL
Institut für Physiologische Chemie I, Heinrich-Heine-Universität Düsseldorf,
P.O. Box 101007, D-40001 Düsseldorf, Germany
ß-Carotene, the most prominent carotenoid, is used for oral
sun protection. Based on the antioxidant properties of carotenoids it
has been suggested that these compounds exhibit skin protective effects.
Carotenoids are quenchers of singlet oxygen and also efficiently
scavenge peroxyl radicals.
When ß-carotene was applied as such or in combination with
α-tocopherol for 12 weeks, erythema formation (sunburn reaction)
induced with a solar light simulator was significantly diminished
from week 8 on (1). Similar protective effects are also achieved
with a diet rich in lycopene (2). It has been demonstrated that the
supplementation with a mixture of carotenoids protects humans
against UV-induced erythema as efficient as ß-carotene alone (3).
The intake of either ß-carotene (24 mg/d) or a mixture of carotenoids
composed of ß-carotene, lycopene and lutein (8mg/d
each) led to similar increases in total carotenoids in skin from wk 0
to 12. Long-term supplementation for 12 wk with 24 mg of a carotenoid
mix supplying similar amounts of ß-carotene, lutein and lycopene
ameliorates UV-induced erythema in humans; the effect is
comparable to the treatment with 24 mg of ß-carotene alone.
The extent of protection with ingested carotenoids is not comparable
to the use of a sunscreen with a high sun protection factor.
However, increasing the basal protection systemically contributes
to the permanent defense against UV light-mediated skin damage.
1. Stahl W. Heinrich U. Jungmann H. Sies H. Tronnier H. Am.J. Clin. Nutr.
2000; 71: 795-798.
2. Stahl W. Heinrich U. Wiseman S. Eichler O. Sies H. Tronnier H. J. Nutr.
2001; 131: 1449-1451.
3. Heinrich U., Gärtner C., Wiebusch M., Eichler O., Sies H., Tronnier H., Stahl
W. J. Nutr. 2003; 133: 98-101
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