Eat for Beauty

Marjet D. Heitzer, Ph.D.

The Plateau-proof Diet Foundation

http://www.plateauproofdiet.com

Email: [email protected]

Consuming a diet rich in beneficial nutrients such as vitamins
and minerals results in many welcomed side effects such as
weight loss and improved health not to mention enhanced beauty.
It is important to state here that this column is concerned with
the effects of nutrients derived from certain foods (not
supplements) on your overall appearance. One of the many
benefits of eating more fruits and vegetables may include
reduced wrinkle formation, leading to younger looking skin. The
definition of a wrinkle is: a small ridge, prominence, or furrow
formed by the shrinking or contraction of any smooth substance.
Of course, by the shear extent of creams that exist to combat
the signs of aging (i.e. wrinkles), no reader needs to be
reminded of the detailed definition.

Although many of us are too familiar with the definition of a
wrinkle, the reasons why we get them may not be clear. During
the aging process, fat as well as collagen and elastin (matrix
proteins responsible for the shape of organs) are lost in the
skin. To combat wrinkle formation, many topical creams either
replace the lost collagen and elastin or relax skin muscles,
resulting in a smoother appearance.

Sun damage by ultraviolet radiation (UVA) is one of the
leading causes of premature aging of the skin. UVA induces
premature aging by generating reactive oxygen species (ROS),
thereby increasing oxidative stress in the skin. ROS induced by
UVA, damages lipid, DNA, and proteins located within skin cells
(1). Furthermore, UVA induces gene expression of certain
enzymes, matrix metalloproteinases, which break down the support
matrix, collagen and elastin, found in skin, possibly leading to
wrinkle formation (1). For this reason, many marketing ads for
wrinkle creams include key words such as free radical,
collagen/elastin booster, and antioxidants.

Beta-carotene is a member of the carotenoid family (the bright
red, yellow, and orange pigments of fruit and vegetables) that
is found in foods such as carrots and green, leafy vegetables.
It is an antioxidant that is a potent ROS scavenger (2). Because
beta-carotene quenches ROS, they can no long damage skin lipids,
proteins, and DNA. Furthermore, beta-carotene represses
UVA-induced matrix metalloproteinase expression, making it one
of the few oral skin protectants that fight against premature
aging.

Along with directly combating premature aging by removing ROS,
beta-carotene may indirectly affect wrinkle formation by
increasing retinoic acid production in the skin. Beta-carotene
is required for retinoic acid production which induces skin cell
proliferation, perhaps leading to a thickening of the skin. In
turn, a thicker skin layer may result in a smoother appearance
of the surface of the skin.

Because beta-carotene accumulates in the epidermis of the skin
by ingestion, it was tested and confirmed to aid in protecting
the skin from UVA-induced premature aging (3). Furthermore, the
levels of beta-carotene obtained from a diet rich in fruits and
vegetables were sufficient to produce the protection from UVA.
Additionally, beta-carotene is phytoprotective (plant-derived
protection) against erythema (redness of skin produced by the
congestion of capillaries in the skin) induced by UVA.

To maintain the skin benefits associated with consumption of
fruits and vegetables rich in beta-carotene, it is important to
maintain consumption of those foods. Because UVA destroys
beta-carotene in the skin, it must be replenished continuously.
Keep eating your brightly-colored vegies.

1.Wertz, K., Seifert, N., Hunziker, P. B., Riss, G., Wyss,
A., Lankin, C., and Goralczyk, R. Beta-carotene inhibits
UVA-induced matrix metallo protease 1 and 10 expression in
keratinocytes by a singlet oxygen-dependent mechanism. Free
Radic Biol Med, 37: 654-670, 2004.

2.Stahl, W. and Sies, H. Bioactivity and protective effects of
natural carotenoids. Biochim Biophys Acta, 1740: 101-107, 2005.

3.Bando, N., Hayashi, H., Wakamatsu, S., Inakuma, T., Miyoshi,
M., Nagao, A., Yamauchi, R., and Terao, J. Participation of
singlet oxygen in ultraviolet-a-induced lipid peroxidation in
mouse skin and its inhibition by dietary beta-carotene: an ex
vivo study. Free Radic Biol Med, 37: 1854-1863, 2004.

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