Pomegranates were certainly the “it” fruit of 2007, making their presence known everywhere from the juice aisle to the department store (Murad Energizing Pomegranate Moisturizer SPF 15, $32.00). Yet, are these luscious fruits good for your skin?
Pomegranates and sun damage
Sun damage has been reported to be the number one preventable cause of skin cancer and premature skin aging. However, it has been proposed that pomegranates can protect against UV-induced damage in human keratinocytes, both UVA and UVB in two separate studies in the Journal of Photochemistry and Photobiology. From the studies, it appears that pomegranates protect against UVA-induced damage by modulating phosphorylation in cellular pathways. When left uninhibited, UVA-induced damage includes the release of oxidative species, resulting in immunosuppression, photodermatoses, photoaging and photocarcinogenesis. Pomegranates appear to protect against UVB-induced damage by inhibiting the UVB-mediated activation of MAPK and NF-κB pathways. When left uninhibited, UVB-induced damage includes inflammation and the release of oxidative species, and ultimately result in erythema, hyperplasia, hyperpigmentation, immunosuppression, photoaging and skin cancer.
Pomegranates — effects similar to retinol and peptides?!
In a 2005 study from the Journal of Ethnopharmacology, it was found that pomegranate seed oil was shown to stimulate keratinocyte (skin cell) proliferation in monolayer culture, and a mild thickening of the epidermis (without the loss of ordered differentiation) was observed in skin organ culture. Unfortunately, the same pomegranate seed oil that stimulated keratinocyte proliferation was without effect on the function of fibroblasts (the cells that produce collagen).
However, pomegranate peel extract was found to stimulate type I procollagen synthesis and inhibited matrix metalloproteinase-1 (MMP-1; interstitial collagenase) production by dermal fibroblasts. On the downside, pomegranate peel extract had no growth-supporting effect on keratinocytes.
Still, the effects are exciting – the study suggests that combined use of pomegranate seed [oil] and peel [extract] may stimulate procollagen synthesis, inhibit matrix metalloproteinases (enzymes that degrade collagen) and stimulate keratinocyte proliferation. More study clearly needs to be done comparing the degree to which pomegranate compares to the collagen-stimulating effects of retinoids and peptides, and to the MMP-inhibiting effects of retinoids.
May lighten skin when taken orally
In this double-blind, placebo-controlled 2006 study in the Journal of Nutritional Science and Vitaminology, it was found that 100-200 mg/day of ellagic acid (a component of pomegranate extract) has an inhibitory effect on a slight pigmentation in the human skin caused by UV irradiation. The effect is dose-dependent, as 100 mg/day resulted in an average 1.35% decrease in luminance to UV-exposed skin, and 200 mg/day resulted in a 1.73% decrease.
A 2005 study in the Journal of Bioscience, Biotechnology and Biochemistry with some of the same authors found that the skin-whitening effect when orally ingesting pomegranate extract as 90% ellagic acid (100 or 1000 mg/kg/day diluted in water with 10 mg/mL or 100 mg/mL, respectively) was similar to when ingesting vitamin C as L-ascorbic acid (600 mg/kg/day diluted in water with 60 mg/mL). Pomegranate extract had the additional effect of reducing the number of DOPA-positive melanocytes in the epidermis of UV-irradiated guinea pigs. The results of the Bioscience, Biotechnology and Biochemistry study suggest that the skin-whitening effect of PE was probably due to inhibition of the proliferation of melanocytes and melanin synthesis by tyrosinase in melanocytes.
May prevent skin cancer
According to this 2004 study in the International Journal of Cancer, it was suggested that topical application of pomegranate extract may possess chemopreventative activity in mice, as it proved capable of inhibiting conventional as well as novel biomarkers of TPA (tetradecanoylphorbol-13-acetate)-induced tumor promotion. Clearly, more study needs to be done on the dosage required for such preventative effects, as well as numerous human studies.
As a result…
Pomegranates are pome-great (punny, I’m sorry); these appear to have many beneficial effects for the skin, from UVA-and UVB-damage control, to matrix metalloproteinase inhibition, to procollagen synthesis, to inhibition of hyperpigmentation. A new favorite for sure — add some to your daily diet, and apply some to your skin! I’ll post when more becomes available about concentrations of ellagic acid in skincare.