articLe | DERMONUTRITION |
Tested Control
6.5 6
5.5 5
4.5 4
3.5 3
Baseline 6wk 12wk Time epidermal differentiation. Nevertheless, the role of GLA
may be more important for improving skin barrier function integrity, as was previously reported for both borage and evening primrose oils. A study by Brosche and Platt (11) showed an improvement in barrier function after supplementation by 320 and 740 mg of GLA in elderly subjects, whereas Muggli (12) used 300 mg of GLA in a younger population to show the improvement in barrier function. Respectively, the relative improvements in TEWL to baseline was 10.8% (7.65 g m−2
hr−1 hr−1 vs 6.82 g m−2 and 8.7 g m−2 hr−1 hr−1
relative to placebo was 7.7% and 9.1% (9.1 g m−2 m−2
vs 7.9 g m−2 hr−1 at
12 weeks; p< 0.05). However, this effect on TEWL occurred at a faster rate (6 weeks) and the percentage improvement in barrier function relative to placebo was greater (13.25%), presumably owing to the improved bioavailability of at least the GLA in the product. Consequently, with this improvement
at 8 weeks; p< 0.05) and hr−1
vs 8.4 g 18wk 24wk *
Figure 5 All values are expressed as means ± SD. Barrier function represented by transepidermal water loss (TEWL) values, expressed in g m−2
hr−1 , measured on
forearm in healthy women, as a function of
consumption of the product. Results are expressed as means ± SEM. Total population (n=72) with effect of treatment on overall
period consumption with *
p=0.026
■ NMFs derived from filaggrin degradation: the free amino acids glycine (G), histidine (H), proline (P), and serine (S) and transformed amino acids pyrolidone carboxylic acid (PCA) and transurocanic acid (TUCA). ■ NMFs derived from sweat: lactate and urea. As filaggrin is degraded at different positions in the
stratum corneum depending on the external environmental conditions, NMF concentrations were measured at different depths. In the most superficial layers (from the surface to 4 μm depth), there was no effect of the treatments on either filaggrin‑derived NMF concentrations (PCA, PCA + UCA + GHPS, PCA + UCA) (Figure 6a) or sweat‑derived NMF (lactate, urea, and lactate and urea). At their surface, corneocytes lose their ability to keep
NMFs intracellular, which are eliminated by cleansing. However, when analysed together (lactate + urea + GHPS + PCA and lactate + urea + GHPS + PCA + UCA), a significant increase was observed in both test groups compared with the control group (data not shown). Examining deeper levels of the stratum corneum, to a
by potentially reducing
inflammation generally, probiotics may lead to an improvement in skin barrier function and skin health as a result.
of skin barrier function by the consumption of this fermented dairy product enriched with BO, vitamin E, and GTPs, it was decided to evaluate whether these ingredients had the capability of increasing stratum corneum NMF levels and, thereby, filaggrin levels as the authors had observed in vitro.
In vivo confocal Raman study examining NMF levels This evaluation was led by an open, double‑blind randomised clinical study conducted on 60 free‑living healthy women (n= 20 per group) showing no signs of skin diseases, receiving twice‑daily doses of the control product, one control and one treated, or two treated products. The treatments were 150 mg GLA, 47 mg catechins, and 2 mg vitamin E, mixed in a dairy matrix containing probiotics (L. casei, L. bulgaricus, and S. thermophilus) for 12 weeks. The amount of NMFs in the stratum corneum was
assessed by confocal Raman spectroscopy on the forearm. Analyses were performed on the following compounds present in the NMFs:
38 ❚ May 2011 |
prime-journal.com
depth of 8 μm, statistical trends were observed between the three groups for GHPS and GHPS + PCA, where the test groups had increased concentrations compared with the control group. Nevertheless, a significant difference was found between the groups for GHPS + PCA + TUCA (p= 0.019); the comparison between groups showed a significant difference between the control group and test group 2 (p= 0.046) and between control group and test group 1 (p= 0.05) (Figure 6a). This led to an approximately threefold higher percentage improvement for both test groups compared to the control group (control group + 4.2%; test group 1 + 11.44%; test group 2 + 11.94%) (Figure 6b). In fact, as filaggrin‑derived NMFs are generated in the second most superficial part of the stratum corneum, this depth (from the
surface to 8 μm depth) is the most relevant to analyse the effects of this product on filaggrin‑derived NMFs. All together, these results imply that the consumption
of this product at both dosages increase stratum corneum NMF levels, possibly by increasing epidermal filaggrin synthesis as demonstrated in vitro. Increased NMF is an indicator of epidermally‑generated filaggrin that contributes to corneocyte maturation, and thereby skin barrier function.
Discussion These studies were the first to demonstrate the concept of dermonutrition from a food. However, all of the ingredients probably contribute to the efficacy, but it is worth discussing their individual effects further. One of the most important fatty acids in the stratum corneum is linoleic acid (LA; 18:2(n‑6)) (7). Its levels are known to be reduced in dry skin and at its most extreme in EFAD. Furthermore, one of the most important ceramides for skin is ceramide‑1 (CER EOS) (21), and its linoleate levels, ceramide‑1 linoleate, are also known to be reduced in atopic dermatitis (21), together with normal skin in both the winter months of
TEWL (gm-2 hr-1 )
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