In recent years the role of phytonutrients such as carotenoids and polyphenols are being investigated for their protective effect on human diseases. Environmental factors including ultraviolet light induced sunburns and other skin diseases are among the important human health disorders. In view of this a recently published clinical study by Wood et al is being discussed here and comments offered:
In this open label clinical study, the authors investigated the effects of an oral supplementation of a nutrient and phytonutrient blend consisting of several plant extracts and nutritional supplements for a period of 8-weeks against ultraviolet radiation (UVR)-induced tissue damage of non-sun-exposed skin, skin carotenoid concentrations, and facial skin characteristics. The primary endpoint was UVR-induced cellular damage assessed by erythema and the number of apoptotic cells at the highest damaging dose of UVR. Secondary variables included facial skin attributes (i.e., elasticity and water loss), dermatologist- and self-assessed facial skin characteristics and overall appearance, and skin carotenoid concentrations. Thirty-six healthy, non-smoking women (40–75 years) with Fitzpatrick skin types I and II were recruited. They consumed four capsules per day, two capsules with breakfast and two capsules with dinner daily. The study was designed properly with appropriate protocols. Primary and secondary endpoints used to evaluate the effect of UVR-induced tissue damage were appropriate. The 8-week treatment period was sufficient to make necessary observations. The phytonutrient blend used was a complex mixture of several plant extracts and phytonutrients. The study showed statistically significant improvement in all the primary and secondary endpoint measurements. Based on these results they conclude that consuming the blend for 8 weeks was sufficient to improve aging defense mechanisms (ADMs).
Since the oral supplement contained several individual components, it is difficult to conclude if all of them are needed or not. Also, there was no justification for the inclusion of these multiple components as well as the dosages used. It is also not clear if the effects were due to any one or more major components and/or synergistic interactions among the components. Because of this, it is almost impossible to understand the possible mechanism of action of the supplement. Overall this study was well executed with good design, protocols and endpoint measurements of skin damage.
Wood et al. Journal of Cosmetic Dermatology. 2017; 16(4): 491-499.