Interesting article (attached) on the effects of dietary supplementation on skin health and aging
Highlights:
Advantages of Oral Administration:
The advantages of this route of administration are that the dietary bioactive compounds are metabolized and then presented to the entire tissue, potentially in an active form. Also, the blood continuously replenishes the skin with these bioactive compounds, which can then be distributed to all skin compartments (i.e. epidermis, dermis, subcutaneous fat and also to sebum)
Disadvantages of Topical Administration:
In the case of the skin, the classical route of antioxidant administration is topical application. However, this topical route of administration can be achieved efficiently only if the particular antioxidant is stable in the preparation as well as on skin, is able to penetrate the skin and is present in its active form (i.e. possible metabolites). In addition, penetration of antioxidants into the skin is influenced by environmental factors, such as temperature,hydration and the presence of other chemicals.
Some highlights about specific nutrients, see article for more:
Vit. E
Indeed, following supplementation, both the natural form (RRR-a-tocopherol) and the synthetic form (all-rac-atocopherol) appear in the blood circulation, whereas only
RRR-a-tocopherol appears in sebum (Vaule et al. 2004).
Carotenoids
Most of the increase in skin carotenoid levels occurs within the first four weeks of supplementation but no plateau is reached during 12 weeks of supplementation.Cessation of supplementation induces a prompt drop of carotenoid level in all skin sites, decreasing by 56% in forehead, 14% in dorsal, 31% for palm of the hand, 35% for back of the hand and 47% inside the arm (Stahl et al. 1998).
Polyphenols
Silibinin, a polyphenol from milk thistle, appeared in mouse skin rapidly after absorption, but 90%was metabolized or excreted within 4 h. The maximum amount of conjugated silibinin in skin was similar to that found in lung, liver and prostate, although the amount of the free form was lower
Conclusions
Different data support the fact that dietary bioactives such as vitamins, carotenoids, polyphenols and trace elements contribute
to maintenance and improvement of skin integrity and physiology, as well as preventing deleterious effects induced
by ageing and environmental stress. Beneficial effects have been demonstrated in various experimental systems including topical application of some of these ingredients. More recently, oral supplements containing various dietary bioactives have also been reported to be beneficial for skin.
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Edited by edward, 28 February 2008 - 07:21 PM.