The Wrinkle Hypothesis Research
In April 2008, researchers at the Tokyo University of Technology reported that long-term skin aging studies supported their hypothesis for a mechanism of wrinkle formation, whereby inflammatory cytokine expression is activated by UV irradiation. This cytokine expression sets up an inflammatory cascade, which triggers dermal fibroblasts to increase the expression of elastase. The increase in elastase production in turn results in the deterioration of the three-dimensional architecture of elastic fibers, reducing skin elasticity, and finally leading to the formation of wrinkles.
Dr. McDaniel, who has extensively studied the impact of solar radiation and other environmental stress and injury on accelerated aging in skin, agrees with this model and believes it could be further amplified, particularly since UVA/UVB affects the up-regulation of inflammatory cytokines within the cell, as well as inducing a cascade of reactive oxygen species (free radical attack). These processes attack the cellular membrane and other diverse targets within the cell. Dr. McDaniel believes both pathways are significantly responsible for assaulting the tissue, resulting in damage to the micro-architecture of the skin, leading to wrinkle formation and accelerated aging.
While many active ingredients claim to up-regulate collagen and elastin production, until the catabolic processes are switched off through inhibition of ROS (reactive oxygen species) and suppression of inflammatory activity, these pro-collagen effects will have limited benefit.
Alpha Linolenic Acid & Wrinkles
In 2002, Japanese researchers demonstrated that dietary ALA inhibited the erythema score after UVB irradiation. They also demonstrated that UVB-induced prostaglandin E2 (PGE2) production was significantly lower in the group fed an ALA-rich diet compared with the control group. The researchers concluded from their results that the type of fatty acids n-6 or n-3 is critical for the suppression of UVB-induced skin lesion when the “skin” fatty acids are modified by dietary manipulation. Anti-inflammatory activity of diet with a relatively high ALA and low linoleic acid content was demonstrated in UVB-irradiated hairless mice model.
Tocotrienols & Wrinkles
The significance of tocotrienols in skin care (and in particular gamma-tocotrienol) has come to light during the past few years. Researchers at Sugiyama Jogakuen University in Japan had previously shown that a vitamin E admixture extracted from palm oil could result in specific distribution of vitamin E isomers in an animal model. This research group concluded that when fed as part of the diet, tocotrienols were selectively taken up in the skin. They also claimed the skin to be a unique tissue in its ability to discriminate between various vitamin E analogs.
In a more recent study presented in April, the same research group investigated whether the increased presence of tocotrienols in the skin could confer a specific anti-aging health benefit, such as protecting the skin from the accelerated aging effect of UVB over-exposure. The group concluded that dietary tocotrienols do indeed protect the skin from damage (including tumor development) induced by UVB, more strongly than the more common form of vitamin E alpha-tocopherol.
The Role of Other Antioxidants
One reason vitamin E has not performed well in earlier studies is that it doesn’t work well in isolation, especially the tocotrienols. As far back as 2000, Lester Packer and colleagues from the University of California, Berkeley, during a presentation at Experimental Biology, noted that tocotrienols are uniformly distributed on the surface of the cellular membrane where they easily collide with ROS and facilitate the recycling activity of the chromanoxyl radical. Dr. Packer reported that vitamin E, as a class of compounds, does not work in isolation from other antioxidants, but instead forms part of an interlinking set of redox reactions with antioxidants such as vitamin C.