Nutritional skin care: health effects of micronutrients and fatty acids

Skin photoaging and the role of antioxidants in its prevention

Photoaging of the skin depends primarily on the degree of ultraviolet radiation (UVR) and on an amount of melanin in the skin (skin phototype). In addition to direct or indirect DNA damage, UVR activates cell surface receptors of keratinocytes and fibroblasts in the skin, which leads to a breakdown of collagen in the extracellular matrix and a shutdown of new collagen synthesis. It is hypothesized that dermal collagen breakdown is followed by imperfect repair that yields a deficit in the structural integrity of the skin, formation of a solar scar, and ultimately clinically visible skin atrophy and wrinkles. Many studies confirmed that acute exposure of human skin to UVR leads to oxidation of cellular biomolecules that could be prevented by prior antioxidant treatment and to depletion of endogenous antioxidants. Skin has a network of all major endogenous enzymatic and nonenzymatic protective antioxidants, but their role in protecting cells against oxidative damage generated by UV radiation has not been elucidated. It seems that skin's antioxidative defence is also influenced by vitamins and nutritive factors and that combination of different antioxidants simultaneously provides synergistic effect.

Effects of environmental factors on edible oil quality of organically grown Camelina sativa

The aim of the present study was to evaluate the potential for the production of edible oil from organically grown camelina ( Camelina sativa L. Crantz), focusing on the influence of environmental factors on nutritional quality parameters. Field experiments with precrop barley were conducted in Norway in the growing seasons 2007, 2008, and 2009. Trials were fully randomized with two levels of nitrogen (N) fertilization, 0 and 120 kg total N ha(-1), and two levels of sulfur (S) fertilization, 0 and 20 kg total S ha(-1). Weather conditions, that is, temperature and precipitation, were recorded. Additional experiments were performed in the years 2008 and 2009 to evaluate the effects of replacing precrop barley with precrop pea. Seed oil content was measured by near-infrared transmittance, and crude oil compositions of fatty acids, phytosterols, tocopherols, and phospholipids were analyzed by chromatography and mass spectrometry. Results showed significant seasonal variations in seed oil content and oil composition of fatty acids, tocopherols, phytosterols, and phospholipids that to a great extent could be explained by the variations in weather conditions. Furthermore, significant effects of N fertilization were observed. Seed oil content decreased at the highest level of N fertilization, whereas the oil concentrations of α-linolenic acid (18:3n-3), erucic acid (22:1n-9), tocopherols, and campesterol increased. Pea compared to barley as precrop also increased the 18:3n-3 content of oil. S fertilization had little impact on oil composition, but an increase in tocopherols and a decrease in brassicasterol were observed. In conclusion, organically grown camelina seems to be well suited for the production of edible oil. Variations in nutritional quality parameters were generally small, but significantly influenced by season and fertilization.

Discovering the link between nutrition and skin aging

Skin has been reported to reflect the general inner-health status and aging. Nutrition and its reflection on skin has always been an interesting topic for scientists and physicians throughout the centuries worldwide. Vitamins, carotenoids, tocopherols, flavonoids and a variety of plant extracts have been reported to possess potent anti-oxidant properties and have been widely used in the skin care industry either as topically applied agents or oral supplements in an attempt to prolong youthful skin appearance. This review will provide an overview of the current literature "linking" nutrition with skin aging.

[Beauty from the inside. Does it really work?]

Skin functions and healthy appearance depend on a sufficient supply of essential nutrients. The relationship between nutrition and skin has become a hot topic that is exciting researchers and clinicians worldwide. Intervention studies indicate that it is in fact possible to manipulate and to delay skin aging and to improve skin conditions through supplementation with selected nutritional supplements. It has been shown that diet-based anti-aging strategies are most effective when directed against extrinsic skin aging. New insights into the effects of orally-administered, biologically active molecules on skin functions have stimulated a continuously growing interest in the development of nutritional supplements and functional food products to benefit human skin. This article attempts to provide a briefly overview to some of the healthy and protective substances used as functional food.

An encapsulated fruit and vegetable juice concentrate increases skin microcirculation in healthy women

BACKGROUND/AIM

Microcirculation in the dermis of the skin is important for nutrient delivery to this tissue. In this study, the effects of a micronutrient concentrate (Juice Plus+®; 'active group'), composed primarily of fruit and vegetable juice powder, on skin microcirculation and structure were compared to placebo.

STUDY DESIGN/METHODS

This 12-week study had a monocentric, double-blind placebo and randomized controlled design with two treatment groups consisting of 26 healthy middle-aged women each. The 'oxygen to see' device was used to evaluate microcirculation. Skin density and thickness were measured using ultrasound. Measurements for skin hydration (Corneometer®), transepidermal water loss and serum analysis for carotenoids and α-tocopherol were also performed.

RESULTS

By 12 weeks, microcirculation of the superficial plexus increased by 39%. Furthermore, skin hydration increased by 9% while skin thickness increased by 6% and skin density by 16% in the active group. In the placebo group, microcirculation decreased, and a slight increase in skin density was observed.

CONCLUSION

Ingestion of a fruit- and vegetable-based concentrate increases microcirculation of the skin at 12 weeks of intervention and positively affects skin hydration, density and thickness.

Diet in dermatology: present perspectives

Many nutrients are essential for life, and an adequate amount of nutrients in the diet is necessary for providing energy, building and maintaining body organs, and for various metabolic processes. The role of food in the induction of various skin disorders and skin diseases leading to nutritional deficiencies is well known. The photo-protective potential of antioxidants, the effects of micronutrient supplementation on the skin immune system, and the modulating effects of fatty acids on skin disorders are well documented. Skin diseases due to nutritional deficiencies, the dietary role in skin immunity and various skin diseases, and the role of antioxidants and other supplements in skin health have been reviewed.

Singlet molecular oxygen-quenching activity of carotenoids: relevance to protection of the skin from photoaging

Carotenoids are known to be potent quenchers of singlet molecular oxygen [O₂ (¹Δ_g)]. Solar light-induced photooxidative stress causes skin photoaging by accelerating the generation of reactive oxygen species via photodynamic actions in which O₂ (¹Δ_g) can be generated by energy transfer from excited sensitizers. Thus, dietary carotenoids seem to participate in the prevention of photooxidative stress by accumulating as antioxidants in the skin. An in vivo study using hairless mice clarified that a O₂ (¹Δ_g) oxygenation-specific peroxidation product of cholesterol, cholesterol 5α-hydroperoxide, accumulates in skin lipids due to ultraviolet-A exposure. Matrix metalloproteinase-9, a metalloproteinase family enzyme responsible for the formation of wrinkles and sagging, was enhanced in the skin of ultraviolet-A -irradiated hairless mice. The activation of metalloproteinase-9 and the accumulation of 5α-hydroperoxide, as well as formation of wrinkles and sagging, were lowered in mice fed a β-carotene diet. These results strongly suggest that dietary β-carotene prevents the expression of metalloproteinase-9 (at least in part), by inhibiting the photodynamic action involving the formation of 5α-hydroperoxide in the skin. Intake of β-Carotene therefore appears to be helpful in slowing down ultraviolet-A -induced photoaging in human skin by acting as a O₂ (¹Δ_g) quencher.

Surface lipids as multifunctional mediators of skin responses to environmental stimuli

Skin surface lipid (SSL) film is a mixture of sebum and keratinocyte membrane lipids, protecting skin from environment. Its composition is unique for the high percentage of long chain fatty acids, and of the polyterpenoid squalene, absent in other human tissues, and in non-human Primates sebum. Here, the still incomplete body of information on SSL as mediators of external chemical, physical, and microbial signals and stressors is revised, focusing on the central event of the continuous oxidative modification induced by the metabolic activity of residential and pathological microbial flora, natural or iatrogenic UV irradiation, exposure to chemicals and cosmetics. Once alpha-tocopherol and ubiquinol-10 antioxidant defences of SSL are overcome, oxidation of squalene and cholesterol gives rise to reactive by-products penetrating deeper into skin layers, to mediate local defensive inflammatory, photo-protective, immune reactions or, at higher concentrations, inducing local but also systemic immune depression, ultimately implicating skin cancerogenesis. Qualitative modifications of SSL represent a pathogenetic sign of diagnostic value in dermatological disorders involving altered sebum production, like pytiriasis versicolor, acne, atopic or seborrheic dermatitis, as well as photo-aging. Achievements of nutriceutical interventions aimed at restoring normal SSL composition and homeostasis are discussed, as feasible therapeutic goals and major means of photo-protection.

The role of phytonutrients in skin health

Photodamage is known to occur in skin with exposure to sunlight, specifically ultraviolet (UV) radiation. Such damage includes inflammation, oxidative stress, breakdown of the extracellular matrix, and development of cancer in the skin. Sun exposure is considered to be one of the most important risk factors for both nonmelanoma and melanoma skin cancers. Many phytonutrients have shown promise as photoprotectants in clinical, animal and cell culture studies. In part, the actions of these phytonutrients are thought to be through their actions as antioxidants. In regard to skin health, phytonutrients of interest include vitamin E, certain flavonoids, and the carotenoids, β-carotene, lycopene and lutein.

Nutritional and antioxidant status by skin types among female adults

This study was performed to analyze the relationship among sebum · hydration content of the skin and nutritional intake, serum antioxidant minerals and antioxidant enzymes, and lipid peroxide concentration in 50 female subjects in their 20s. The skin type was divided into Dry Skin, Mixed Skin, and Oily Skin, and the dry skin group was 14%, the mixed skin group was 56%, and the oily skin group was 30% of all subjects. The average age of the subjects was 20.54 ± 1.43 years and BMI was 20.66. The average sebum content in each group was in the order of T-zone>forehead>chin>cheek. In case of the T-zone, a significant difference between the dry skin group and the oily skin group was observed, suggesting that the area is most sensitive to sebum content by skin type. Significant differences were not observed in energy and nutrient intakes by skin type. Serum concentrations of antioxidant minerals such as copper, manganese, zinc and selenium were not significantly different among the groups, but the dry skin group tended to be higher than the oily skin group. Serum catalase was significantly higher in the oily skin group (P < 0.05), and MDA was significantly higher in the mixed skin group (P < 0.05). The hydration of the cheek and serum zinc showed a negative correlation, and the sebum content of the cheek and GPx showed a significant negative correlation. The hydration of the forehead and serum copper showed a significant negative correlation, and the hydration of the forehead and GPx showed a significant positive correlation. The hydration of the chin and serum SOD showed a significant positive correlation. With these results, it is considered that the basic condition of nutritional status can affect the skin health.

Nutritional approach to sun protection: a suggested complement to external strategies

The increasing incidence of skin cancer despite the use of externally applied sun protection strategies, alongside research showing that nutrients reduce photo-oxidative damage, suggest nutritional approaches could play a beneficial role in skin cancer prevention. Penetrating photo-oxidative ultraviolet A radiation reduces skin and blood antioxidants and damages cell components, including DNA. Dietary antioxidant vitamins, minerals, and phytochemicals in addition to n-3 polyunsaturated fatty acids, n-9 monounsaturated fatty acids, and low pro-inflammatory n-6 polyunsaturated fatty acids, have demonstrated protective properties. The presence of these elements in the traditional Greek-style Mediterranean diet may have contributed to the low rates of melanoma in the Mediterranean region despite high levels of solar radiation. This suggests a potentially relevant model for studying dietary/nutritional supplementation for lifelong internal support of sun-protection mechanisms, which could complement external strategies.

Association of dietary fat, vegetables and antioxidant micronutrients with skin ageing in Japanese women

Daily diet may have implications for skin ageing. However, data on the relationship between diet and the parameters of skin conditions are scarce. The present study aimed to examine the associations of biophysical properties of the skin of women with intakes of fats and antioxidant micronutrients as well as food groups as sources of these nutrients. In a cross-sectional study, we measured the hydration, surface lipids and elasticity of the skin of 716 Japanese women using non-invasive techniques. The extent of facial wrinkles in the crow's-foot area was determined by observation using the Daniell scale. Each subject's usual diet was determined with the use of a validated FFQ. After controlling for covariates including age, smoking status, BMI and lifetime sun exposure, the results showed that higher intakes of total fat, saturated fat and monounsaturated fat were significantly associated with increased skin elasticity. A higher intake of green and yellow vegetables was significantly associated with a decreased Daniell wrinkling score. Intake of saturated fat was significantly inversely associated with the Daniell wrinkling score after additional adjustment for green and yellow vegetable intake. Further studies with more accurate measurement methods are needed to investigate the role of daily diet in skin ageing.

Nutrition and nutritional supplementation: Impact on skin health and beauty

Skin acts as a natural barrier between internal and external environments thus plays an important role in vital biological functions such as protection against mechanical/chemical damages, micro-organisms, ultraviolet damage. Nutrition has a critical impact on strengthening skin's capabilities to fight against these multiple aggressions.Nutritional deficiencies are often associated with skin health disorders, while diets can either positively or negatively influence skin condition. More recently, the concept of nutritional supplementation has emerged as a new strategy in the daily practice of dermatology as well as a complementary approach to topical cosmetics in the field of beauty. Focusing on human clinical data, this paper proposes to illustrate the link between skin health and nutrition and to exemplify the beneficial actions of nutritional supplementation in skin health and beauty.

Supplementation with Evelle® improves skin smoothness and elasticity in a double‐blind, placebo‐controlled study with 62 women

OBJECTIVE

To investigate whether nutritional intervention with a proprietary formulation and other micronutrients may favourably alter skin roughness and elasticity.

METHODS

Sixty-two women aged 45-73 years participated in a double-blind, placebo-controlled trial testing the efficacy of a proprietary oral supplement for skin nutrition (Evelle), for improvement of skin elasticity and roughness. The active ingredients were vitamins C and E, carotenoids, selenium, zinc, amino acids and glycosaminoglycans, blueberry extract and Pycnogenol.

RESULTS

Skin elasticity, measured using an optical cutometer, was found to be statistically significantly increased by 9% after 6 weeks of treatment compared with placebo (p=0.0351). Skin roughness, as evaluated by three-dimensional microtopography imaging, was found to be statistically significantly lowered by 6% compared with the control group after 12 weeks treatment (p=0.0157).

CONCLUSION

Evelle can potentially improve visible signs of cutaneous ageing.

Something New Under the Sun: Lutein’s Role in Skin Health

Lutein has a well-established role in eye health. There is accumulating evidence that lutein may also play a role in skin health. Its presence in human skin along with its antioxidant and anti-inflammatory activity provide a rationale for a role in preventing ultraviolet-induced damage to skin. Epidemiological studies support a role for diets high in lutein and decreased risk of wrinkling and cancer. Recent intervention studies have shown lutein to prevent ultraviolet-induced carcinogenesis in animals and to improve skin physiology parameters in humans, including antioxidant protection from ultraviolet light irradiation. In this review, the authors explore the rationale and plausibility of a role for lutein in skin health.

Food intake, dietary patterns, and actinic keratoses of the skin: a longitudinal study

BACKGROUND

Actinic keratoses (AKs) are premalignant actinic tumors of the skin. Evaluation of the role of diet in their development is lacking.

OBJECTIVE

The objective was to determine whether intake of certain food groups or dietary patterns retard the occurrence of AKs over a 4.5-y period.

DESIGN

In a community-based study of skin cancer in Queensland, Australia, food intake of 1119 adults was assessed in 1992, 1994, and 1996 by using a validated food-frequency questionnaire. Dermatologists counted prevalent AKs during full-body skin examinations in 1992 and 1996. The relative ratio (RR) of AK counts in 1996 relative to 1992 was compared across increasing intakes of 26 food groups, and for 3 dietary patterns identified by principal components analysis, with the use of generalized linear models with negative binomial distribution, allowing for repeated measures. All analyses were adjusted for confounding factors, including skin color and sun exposure indexes.

RESULTS

AK acquisition decreased by 28% (RR: 0.72; 95% CI: 0.55, 0.95) among the highest consumers of oily fish (average of one serving every 5 d) compared with those with minimal intake. Similarly, the rate of acquisition of AKs was reduced by 27% (RR: 0.73; 95% CI: 0.54, 0.99) in those with the highest consumption of wine (average of half a glass a day in this study population). There was no consistent association of dietary pattern with AK acquisition.

CONCLUSION

Moderate intake of oily fish and of wine may decrease the acquisition of AKs and thus complement sun protection measures in the control of actinic skin tumors.

Vitamin D and skin cancer: a meta-analysis

A comprehensive bibliographic search of the literature was conducted to identify studies on Cutaneous Malignant Melanoma (CMM) and non-melanoma skin cancer (NMSC), Vitamin D receptor (VDR) polymorphisms, Vitamin D intake and 25(OH)D serum levels. Fully adjusted risk estimates were found and extracted for the two polymorphisms FokI and BsmI and Vitamin D intake. Ten studies were included in the meta-analysis, with a total of 6805 skin cancer cases. We found an association with CMM for both polymorphisms. The summary relative risks (SRR) for the studies on CMM were: 1.21 (1.03-1.42) and 1.21 (0.95-1.54) for the Ff and ff versus wild-type of FokI, respectively. The SRR for ff versus wild-type became significant with the inclusion of NMSC. The SRR for the studies on CMM were: 0.78 (0.65-0.92) and 0.75 (0.59-0.95) for the Bb and BB versus wild-type of BsmI, respectively. There is also a slight indication of a role of dietary Vitamin D in CMM development. In conclusion, this meta-analysis suggests a possible significant role of VDR FokI and BsmI polymorphism in CMM and NMSC risk. The association with Vitamin D intake is less clear and further studies could be useful to clarify the role of diet.

Consumption of functional fermented milk containing borage oil, green tea and vitamin E enhances skin barrier function

As emerging studies show that skin functioning can be improved with orally imbibed ingredients, we decided to investigate a mixture of borage oil, catechins, vitamin E and probiotics, all known for their reported effects on epidermal function, in a fermented dairy product, for the first time. Gamma-linolenic acid (GLA) and catechins bioavailability and their effects on skin functionality have not been previously investigated from a fermented dairy product. Firstly, we assessed the bioavailability of GLA and catechins mixed in a fermented dairy matrix by measuring their levels in chylomicrons and plasma samples respectively. For the GLA contained in the dairy matrix, the area under the curve and time for maximal absorption were significantly different to the same kinetic parameters compared with absorption from the free oil indicating improved oral bioavailability. However, the overall absorption of catechins over the 6-h period was identical for both product forms. These results were sufficiently promising to warrant a 24 week skin nutrition intervention study in female volunteers having dry and sensitive skin. The product improved stratum corneum barrier function compared with a control product as early as 6 weeks after the consumption which continued throughout the rest of the study. The reduction in transepidermal water loss relative to control was maintained throughout the trial despite seasonal changes. Moreover, as a result of the enhanced bioavailability, a much greater effect on skin barrier function occurred than reported previously for the individual ingredients. Nevertheless, body mass index significantly influenced various outcome measurements of this study.

Oral intake of soy isoflavone aglycone improves the aged skin of adult women

A double-blind, placebo-controlled trial was conducted to clinically evaluate the effect of soy isoflavone aglycone on the aged skin of middle-aged women. Twenty-six women volunteers in their late 30s and early 40s were randomly assigned to receive either a test food (13 women, the test food group) or a placebo food (13 women, the control group). These groups were given the test food (40 mg of soy isoflavone aglycone per day) and placebo, respectively, for 12 wk. The extent of linear and fine wrinkles at the lateral angle of the eyes was selected as the major evaluation criterion to assess the effects of foods, and the wrinkles' area ratio was used as the evaluation parameter. The extent of skin microrelief at the lateral angle of eyes and that of malar skin elasticity were used as secondary evaluation criteria, and the skin microrelief's area ratio and recovery of skin elasticity were used as the respective evaluation parameters. These parameters were assessed 4, 8, and 12 wk after the start of the test food or placebo intake. The test food group showed a statistically significant improvement of fine wrinkles at week 12 (p<0.05) and of malar skin elasticity at week 8 (p<0.05), compared with the control group. Although there was no significant difference between the test food group and the control group regarding effects on skin microrelief at lateral angle of the eyes, a significant intragroup improvement was observed at week 8 in the test food group (p<0.05). As for the test food safety, none of the subjects presented adverse symptoms during the study period or discontinued the intake of the test food. These data indicate that the oral intake of 40 mg soy isoflavone aglycones per day improves the aged skin of middle-aged women.

Dietary nutrient intakes and skin-aging appearance among middle-aged American women

BACKGROUND

Nutritional factors play a key role in normal dermatologic functioning. However, little is known about the effects of diet on skin-aging appearance.

OBJECTIVE

We evaluated the associations between nutrient intakes and skin-aging appearance.

DESIGN

Using data from the first National Health and Nutrition Examination Survey, we examined associations between nutrient intakes and skin aging in 4025 women (40-74 y). Nutrients were estimated from a 24-h recall. Clinical examinations of the skin were conducted by dermatologists. Skin-aging appearance was defined as having a wrinkled appearance, senile dryness, and skin atrophy.

RESULTS

Higher vitamin C intakes were associated with a lower likelihood of a wrinkled appearance [odds ratio (OR) 0.89; 95% CI: 0.82, 0.96] and senile dryness (OR: 0.93; 95% CI: 0.87, 0.99). Higher linoleic acid intakes were associated with a lower likelihood of senile dryness (OR: 0.75; 95% CI: 0.64, 0.88) and skin atrophy (OR: 0.78; 95% CI 0.65, 0.95). A 17-g increase in fat and a 50-g increase in carbohydrate intakes increased the likelihood of a wrinkled appearance (OR: 1.28 and 1.36, respectively) and skin atrophy (OR: 1.37 and 1.33, respectively). These associations were independent of age, race, education, sunlight exposure, income, menopausal status, body mass index, supplement use, physical activity, and energy intake.

CONCLUSIONS

Higher intakes of vitamin C and linoleic acid and lower intakes of fats and carbohydrates are associated with better skin-aging appearance. Promoting healthy dietary behaviors may have additional benefit for skin appearance in addition to other health outcomes in the population.

Anti-wrinkling effects of the mixture of vitamin C, vitamin E, pycnogenol and evening primrose oil, and molecular mechanisms on hairless mouse skin caused by chronic ultraviolet B irradiation

BACKGROUND

Naturally occurring antioxidants were used to regulate the skin damage caused by ultraviolet (UV) radiation because several antioxidants have demonstrated that they can inhibit wrinkle formation through prevention of matrix metalloproteinases (MMPs) and/or increase of collagen synthesis.

OBJECTIVE

We examined the effect of oral administration of the antioxidant mixture of vitamin C, vitamin E, pycnogenol, and evening primrose oil on UVB-induced wrinkle formation. In addition, we investigated the possible molecular mechanism of photoprotection against UVB through inhibition of collagen-degrading MMP activity or through enhancement of procollagen synthesis in mouse dorsal skin.

METHODS

Female SKH-1 hairless mice were orally administrated the antioxidant mixture (test group) or vehicle (control group) for 10 weeks with UVB irradiation three times a week. The intensity of irradiation was gradually increased from 30 to 180 mJ/cm2. Microtopographic and histological assessment of the dorsal skins was carried out at the end of 10 weeks to evaluate wrinkle formation. Western blot analysis and EMSA were also carried out to investigate the changes in the balance of collagen synthesis and collagen degradation.

RESULTS

Our antioxidant mixture significantly reduced UVB-induced wrinkle formation, accompanied by significant reduction of epidermal thickness, and UVB-induced hyperplasia, acanthosis, and hyperkeratosis. This antioxidant mixture significantly prevented the UVB-induced expressions of MMPs, mitogen-activated protein (MAP) kinase, and activation of activator protein (AP)-1 transcriptional factor in addition to enhanced type I procollagen and transforming growth factor-beta2 (TGF-beta2) expression.

CONCLUSION

Oral administration of the antioxidant mixture significantly inhibited wrinkle formation caused by chronic UVB irradiation through significant inhibition of UVB-induced MMP activity accompanied by enhancement of collagen synthesis.

[Systemic photoprotection through carotenoids]

Nutritional supplements are increasingly used to protect human skin against environmentally-induced damage, most importantly as a consequence of ultraviolet radiation exposure. beta-carotene is a major constituent of comercially available products administered for systemic photoprotection. Studies on the systemic use of beta-carotene provide evidence that 15-30 mg/d over a period of about 10-12 wk produces a protective effect against UV-induced erythema. Similar effects have been attributed to mixtures of carotenoids or after long-term intake of dietary products rich in carotenoids. Supplementation with carotenoids contributes to basal protection of the skin but is not sufficent to obtain complete protection against severe UV irradiation.

Modification of skin composition by conjugated linoleic acid alone or with combination of other fatty acids in mice

The effects of conjugated linoleic acid (CLA), γ-linolenic acid (GLA), linoleic acid (LA), and their combinations, on skin composition in mice were investigated. Mice (8 weeks old) were orally administered with either LA, GLA, CLA, LA + GLA, LA + CLA, or CLA + GLA for 4 weeks. Then, the skin was analysed for triacylglycerol content, fatty acid composition and collagen content. Additionally, thicknesses of the dermis layer and subcutaneous tissue layer, and the size and number of adipocytes were measured histologically. The skin fatty acid composition was modified depending upon the fatty acid composition of supplemented oils. In each oil-alone group, skin triacylglycerol content was the highest in LA, followed by GLA and CLA treatments. Combinations with CLA had a similar triacylglycerol content compared with the CLA-alone group. No significant changes in collagen content were observed among any treatments. The effects on subcutaneous thickness were similar to the results obtained in the triacylglycerol contents, where groups supplemented with CLA alone or other fatty acids had significantly thinner subcutaneous tissue compared with the LA-alone group. However, no significant difference was detected in the thickness of the dermis layers. The number of adipocytes was highest in the LA + GLA group and tended to be reduced by CLA with or without the other fatty acids. These results suggest that CLA alone or in combination with other fatty acids strongly modifies skin composition in mice.

Non-invasive methods and stimuli for evaluating the skin's microcirculation

Vessels in the skin are arranged into superficial and deep horizontal plexuses and they are involved in thermoregulation, oxygen and nutritional support. The skin has a large number of functions and broad appeal spanning basic mechanistic and clinical research. Indeed, the skin can be used as a marker of normal and impaired vascular control and, owing to its accessibility and frequent involvement, is easy to investigate non-invasively. A large number of non-invasive methods are available for investigating the skin, ranging from those that permit the visualisation of microvessels, to those that monitor blood flow or one of its derivatives (e.g., skin temperature and transcutaneous oxygen). Such methods can be combined with non-invasive, dynamic stimuli (e.g., the use of cold or warm stimuli, activation of the peripheral nervous system or local neuronal systems, and the topical application of vasoactive drugs) and this potentially enables the differentiation of underlying disorders (e.g., primary from secondary Raynaud's phenomenon) and also to quantify changes over time or following intervention. The present article outlines the non-invasive methods and dynamic tests that can be used to investigate the microcirculation of the skin.

Antioxidant supplements improve parameters related to skin structure in humans

In the present study we investigated the influence of two different antioxidant supplements composed of carotenoids, vitamin E and selenium on parameters related to skin health and skin aging. Thirty-nine volunteers with healthy, normal skin of skin type 2 were divided into 3 groups (n = 13) and supplemented for a period of 12 weeks. Group 1 received a mixture of lycopene (3 mg/day), lutein (3 mg/day), beta-carotene (4.8 mg/day), alpha-tocopherol (10 mg/day) and selenium (75 microg/day). Group 2 was supplemented with a mixture of lycopene (6 mg/day), beta-carotene (4.8 mg/day), alpha-tocopherol (10 mg/day) and selenium (75 microg/day). Group 3 was the placebo control. Upon supplementation serum levels of selected carotenoids increased in both verum groups. Skin density and thickness were determined by ultrasound measurements. A significant increase for both parameters was determined in the verum groups. Roughness, scaling, smoothness and wrinkling of the skin were determined by Surface Evaluation of Living Skin (Visioscan). Roughness and scaling were improved by the supplementation with antioxidant micronutrients. In the placebo group no changes were found for any of the parameters.

Effect of a novel dietary supplement on skin aging in post-menopausal women

OBJECTIVE

The aim of the present study was to quantify the effects on skin in post-menopausal women of a novel dietary supplement (Imedeen Prime Renewal) that contained soy extract, fish protein polysaccharides, extracts from white tea, grape seed and tomato, vitamins C and E as well as zinc and chamomile extract.

DESIGN

The study was a 6-month double blind, placebo controlled, randomized study on healthy post-menopausal females.

SETTING

The study was performed at a commercial Contract Research Organisation (TJ Stephens & Associates Inc., TX, USA).

INTERVENTIONS

Two tablets of Imedeen Prime Renewal or placebo were given twice daily for 6 months.

SUBJECTS

Thirty-eight (active group) and 42 (placebo group) subjects completed the study out of 100.

RESULTS

Clinical grading showed that the active group had a significantly greater improvement (P < 0.05) compared to placebo for the face after 6 months treatment for: forehead, periocular and perioral wrinkles, mottled pigmentation, laxity, sagging, under eye dark circles and overall apperance; skin on the décolletage after 2, 3 and 6 months treatment and skin on the hand after 3 and 6 months treatment. Photo evaluation showed that the active group had a significantly greater improvement (P < 0.05) on the face after 3 and 6 months for several parameters. Ultrasound measurements showed that the active group had a significantly greater improvement (P < 0.0001) for density measurements after 6 months treatment.

CONCLUSION

In summary, this novel dietary supplement, Imedeen Prime Renewal, provides improved condition, structure and firmness of the skin in post-menopausal women after 6 months.

Does the plasma level of vitamins A and E affect acne condition?

BACKGROUND

Vitamin A and E are lipid soluble antioxidants that are necessary for our health. Deficiency in these vitamins can cause serious diseases. Administration of vitamin A and E to patients with acne was shown to improve their acne condition.

AIMS

To test the relationship between plasma vitamin A and E levels and acne.

METHODS

Plasma vitamin A and E concentrations were determined by high performance liquid chromatography in 100 newly diagnosed untreated patients with acne and were compared with those of 100 age-matched healthy controls. Patients were carefully graded using the Global Acne Grading System.

RESULTS

We found that plasma vitamin A concentrations in patients with acne were significantly lower than those of the control group (336.5 vs. 418.1 mug/L, respectively) P = 0.007. We also found that plasma vitamin E concentrations in patients with acne were significantly lower than those of controls (5.4 vs. 5.9 mg/L) P = 0.05. In addition, we found that there is a strong relationship between decrease in plasma vitamin A levels and increase in the severity of acne condition. Patients with severe acne had significantly lower plasma concentrations of vitamins A and E than did those with lower acne grade and the age-matched healthy controls.

DISCUSSION

Based on our results, we conclude that low vitamin A and E plasma levels have an important role in the pathogenesis of acne and in the aggravation of this condition.

Dietary feeding of silibinin prevents early biomarkers of UVB radiation-induced carcinogenesis in SKH-1 hairless mouse epidermis

Solar radiation is the causal etiologic factor in the development of nonmelanoma skin cancer (NMSC). Depletion of the stratospheric ozone layer leads to an increase in ambient UV radiation loads, which are expected to further raise skin cancer incidence in many temperate parts of the world, including the United States, suggesting that skin cancer chemopreventive approaches via biomarker efficacy studies or vice versa are highly warranted. Based on our recent study reporting strong efficacy of silibinin against photocarcinogenesis, we assessed here the protective effects of its dietary feeding on UVB-induced biomarkers involved in NMSC providing a mechanistic rationale for an early-on silibinin efficacy in skin cancer prevention. Dietary feeding of silibinin at 1% dose (w/w) to SKH-1 hairless mice for 2 weeks before a single UVB irradiation at 180 mJ/cm(2) dose resulted in a strong and significant (P < 0.001) decrease in UVB-induced thymine dimer-positive cells and proliferating cell nuclear antigen, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, and apoptotic sunburn cells together with an increase (P < 0.001) in p53 and p21/cip1-positive cell population in epidermis. These findings suggest that dietary feeding of silibinin affords strong protection against UVB-induced damages in skin epidermis by (a) either preventing DNA damage or enhancing repair, (b) reducing UVB-induced hyperproliferative response, and (c) inhibiting UVB-caused apoptosis and sunburn cell formation, possibly via silibinin-caused up-regulation of p53 and p21/cip1 as major UVB-damage control sensors.

Protective effects of dietary soy isoflavones against UV-induced skin-aging in hairless mouse model

OBJECTIVE

This study investigated the anti-aging effects of dietary isoflavones on photoaged hairless mouse skin.

METHODS

Female hairless mice were administered soy isoflavone extract orally and irradiated with UV light for four weeks. The effects of the isoflavones on the skin appearance, collagen deposition and epidermal thickness in the UV-damaged mouse skin were measured using bioengineering and histochemical methods. In addition, the influence of the isoflavones on the collagen metabolism in the UVB-irradiated human skin fibroblasts was also investigated.

RESULTS

In the isoflavone treated group, the skin had a better appearance and less wrinkling than that of the control group. Additionally, the amount of collagen deposition was higher in the isoflavone group. In the human fibroblast cells, the amount of procollagen de novo synthesized did not increase after isoflavone treatment and/or UV irradiation. However, the increase in the expression of the metalloproteinases (MMPs) as a result of UV irradiation was suppressed by the isoflavone treatment.

CONCLUSIONS

It appears that isoflavones had an anti-aging effect on the UV-damaged hairless mice model, which is partly due to the inhibitory effects on UV-induced MMP-1 expression and the subsequent collagen degradation.

Meat as a component of a healthy diet - are there any risks or benefits if meat is avoided in the diet?

Meat is frequently associated with a "negative" health image due to its "high" fat content and in the case of red meat is seen as a cancer-promoting food. Therefore, a low meat intake, especially red meat is recommended to avoid the risk of cancer, obesity and metabolic syndrome. However, this discussion overlooks the fact, that meat is an important source for some of micronutrients such as iron, selenium, vitamins A, B12 and folic acid. These micronutrients are either not present in plant derived food or have poor bioavailability. In addition, meat as a protein rich and carbohydrate "low" product contributes to a low glycemic index which is assumed to be "beneficial" with respect to overweight, the development of diabetes and cancer (insulin resistance hypothesis). Taken together meat is an important nutrient for human health and development. As an essential part of a mixed diet, meat ensures adequate delivery of essential micronutrients and amino acids and is involved in regulatory processes of energy metabolism.

[Anti-aging medicine in dermatologic practice]

In the future, the increasing number of older individuals will play an even greater social and medicopolitical role. One challenge for dermatology is to incorporate preventive or anti-aging measures into daily practice. Solid understanding of the mechanisms of aging is required. An organized approach to such patients with emphasis on history, physical examination, imaging and skin physiology studies, and laboratory diagnosis is presented. Topical and systemic interventions should be based on the results of this complete evaluation.

Vitamin E Delivery to Human Skin by a Rinse-Off Product: Penetration of α-Tocopherol versus Wash-Out Effects of Skin Surface Lipids

alpha-Tocopherol, the major biologically active form of vitamin E, represents a frequently added lipophilic compound of skin care products. Despite its emerging use in rinse-off formulations, little is known on its efficacy with respect to its deposition or its antioxidant potential in human skin. The objective of this study was to investigate whether the single use of an alpha-tocopherol-enriched rinse-off product provides effective deposition of alpha-tocopherol on human stratum corneum. To test this, forearm skin of 13 volunteers was washed either with an alpha-tocopherol-enriched rinse-off product (test product, TP) or with an alpha-tocopherol-free vehicle control (control product, CP) (contralateral arm) using a standardized wash protocol. Thereafter, skin surface lipids were extracted with pure ethanol after the wash procedure as well as after 24 h. Additionally, one group of volunteers was subjected to irradiation of their forearms with low-dose UVA (8 J/cm(2)) prior to lipid extraction. Skin lipid extracts were analyzed by high performance liquid chromatography using electrochemical detection for vitamin E and UV detection for squalene (SQ) and squalene monohydroperoxide. The results of this in vivo study demonstrated that (1) while CP treatment lowers, TP treatment strongly increases alpha-tocopherol levels of skin barrier lipids; (2) increased vitamin E deposition levels were maintained for a period of at least 24 h, and (3) TP treatment significantly inhibited photooxidation of SQ. In conclusion, the use of alpha-tocopherol-enriched rinse-off products may help to maintain the integrity of the skin barrier by providing protection against photooxidative stress at the level of skin surface lipids.

Nutritional protection against skin damage from sunlight

The concept of systemic photoprotection by dietary means is gaining momentum. Skin is continuously exposed to ultraviolet (UV) radiation, the major cause of skin disorders such as sunburn, photodamage, and nonmelanoma skin cancer. Most of the erythemal annual UV dose is encountered under nonvacation conditions, when no sunscreen is applied. In the absence of topically added compounds, skin protection depends solely on endogenous defense. Micronutrients can act as UV absorbers, as antioxidants, or can modulate signaling pathways elicited upon UV exposure. UV-induced erythema is a suitable parameter to assess photoprotection. Dietary protection is provided by carotenoids, tocopherols, ascorbate, flavonoids, or n-3 fatty acids, contributing to maintenance resistance as part of lifelong protection.