https://www.jidonline.org/article/S0022-202X(15)36897-4/fulltext

The post An Unexpected Role: UVA-Induced Release of Nitric Oxide from Skin May Have Unexpected Health Benefits appeared first on EMFSA.

Abstract

In the last decade, it has been proposed that the sun’s IR-A wavelengths might be deleterious to human skin and that sunscreens, in addition to their desired effect to protect against UV-B and UV-A, should also protect against IR-A (and perhaps even visible light). Several studies showed that NIR may damage skin collagen content via an increase inMMP-1 activity in the same manner as is known for UVR. Unfortunately, the artificial NIR light sources used in such studies were not representative of the solar irradiance. Yet, little has been said about the other side of the coin. This article will focus on key information suggesting that IR-A may be more beneficial than deleterious when the skin is exposed to the appropriate irradiance/dose of IR-A radiation similar to daily sun exposure received by people in real life.IR-A might even precondition the skin–a process called photo prevention–from an evolutionary standpoint since exposure to early morning IR-A wavelengths in sunlight may ready the skin for the coming mid-day deleterious UVR. Consequently IR-A appears to be the solution, not the problem. It does more good than bad for the skin. It is essentially a question of intensity and how we can learn from the sun. © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

https://pubmed.ncbi.nlm.nih.gov/26745730/

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Abstract

Sleep is intrinsically tied to mental and overall health. Short sleep duration accompanies the modern lifestyle, possibly reaching epidemic proportions. The pandemic and subsequent lockdowns determined a fundamental shift in the modern lifestyle and had profound effects on sleep and mental health. This paper aims to provide an overview of the relationship between sleep, mental health and COVID-19. Contrasting outcomes on sleep health have been highlighted by most reports during the pandemic in the general population. Consequently, while longer sleep durations have been reported, this change was accompanied by decreases in sleep quality and altered sleep timing. Furthermore, an increased impact of sleep deficiencies and mental health burden was generally reported in health care workers as compared with the adult general population. Although not among the most frequent symptoms during the acute or persistent phase, an increased prevalence of sleep deficiencies has been reported in patients with acute and long COVID. The importance of sleep in immune regulation is well known. Consequently, sleep deficiencies may influence multiple aspects of COVID-19, such as the risk, severity, and prognosis of the infection and even vaccine response.

https://www.mdpi.com/1660-4601/19/6/3497/htm

The post Time to Sleep?—A Review of the Impact of the COVID-19 Pandemic on Sleep and Mental Health appeared first on EMFSA.

Abstract

Light plays a fundamental role in the ecology of organisms in nearly all habitats on Earth and is central for processes such as vision and the entrainment of the circadian clock. The poles represent extreme light regimes with an annual light cycle including periods of Midnight Sun and Polar Night. The Arctic Ocean extends to the North Pole, and marine light extremes reach their maximum extent in this habitat. During the Polar Night, traditional definitions of day and night and seasonal photoperiod become irrelevant since there are only “twilight” periods defined by the sun’s elevation below the horizon at midday; we term this “midday twilight.” Here, we characterize light across a latitudinal gradient (76.5° N to 81° N) during Polar Night in January. Our light measurements demonstrate that the classical solar diel light cycle dominant at lower latitudes is modulated during Arctic Polar Night by lunar and auroral components. We therefore question whether this particular ambient light environment is relevant to behavioral and visual processes. We reveal from acoustic field observations that the zooplankton community is undergoing diel vertical migration (DVM) behavior. Furthermore, using electroretinogram (ERG) recording under constant darkness, we show that the main migratory species, Arctic krill (Thysanoessa inermis) show endogenous increases in visual sensitivity during the subjective night. This change in sensitivity is comparable to that under exogenous dim light acclimations, although differences in speed of vision suggest separate mechanisms. We conclude that the extremely weak midday twilight experienced by krill at high latitudes during the darkest parts of the year has physiological and ecological relevance.

https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3001413

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Jun 14, 2021

Dr. med. Alexander Wunsch

Presentation (approx. 22 min.) by Dr. med. Alexander Wunsch, held online on 09 June 2021 on the occasion of the 4th International Scientific Congress of the International College of Cosmetology. The presentation covers the three topics of UV radiation, vitamin D and the significance of full spectra.

The post Sunlight & Health Update 2021 appeared first on EMFSA.

 https://doi.org/10.1093/eurpub/ckab059

Abstract

Background

The prevalence of prostate cancer (PC) is increasing worldwide. An association between sunlight exposure and PC risk has been described by a previously published meta-analysis, although the level of statistical significance was not reached. We have, therefore, performed an updated systematic review and meta-analysis to further elucidate this potential connection.

Methods

To identify relevant articles, we conducted an in-depth search of 4 electronic databases (PubMed, Embase, the Web of Science and Scopus) for manuscripts published prior to March 2021. A random-effects model was used to compute a meta-estimate of the effects of sunlight exposure on risk of PC.

Results

Of the 5680 articles that were initially identified in our search, 12 observational epidemiological studies encompassing 29 282 cases of PC were selected for inclusion in the qualitative systematic review. Of these, two case-control studies were excluded from the meta-analysis. Comparing highest-to-lowest exposure, personal sunlight exposure was significantly associated with a decreased risk of PC [odds ratio (OR) = 0.67, 95% CI: 0.57–0.78] in a random-effects meta-analysis; however, high heterogeneity was present (I² = 85.9%). Comparing moderate-to-lowest exposure, there was a non-significant relationship between personal sunlight exposure and the risk of PC (OR = 0.87, 95% CI: 0.68–1.10; I² = 74.0%).

Conclusions

Our findings indicate that exposure to sunlight may protect against PC. The limitations of our research are occurrence of publication bias and a substantial heterogeneity due to a diversity of criteria for measuring sunlight exposure.

Extract

In summary, PC risk decreased in association with exposure to solar radiation, especially intermittent intense exposure. Nonetheless, care should be taken when drawing a general conclusion because only a limited number of prospective cohort studies were selected in this study and the results from observational studies cannot elucidate the causal relationship. In addition, all personal sunlight exposures that showed the strongest correlation were results derived from only case-control studies. Therefore, further large-scale prospective cohort studies are warranted to validate the results of this study.

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Abstract

Natural sunlight permits organisms to synchronize their physiology to the external world. However, in current times, natural sunlight has been replaced by artificial light in both day and nighttime. While in the daytime, indoor artificial light is of lower intensity than natural sunlight, leading to a weak entrainment signal for our internal biological clock, at night the exposure to artificial light perturbs the body clock and sleep. Although electric light at night allows us “to live in darkness”, our current lifestyle facilitates nighttime exposure to light by the use, or abuse, of electronic devices (e.g., smartphones). The chronic exposure to light at nighttime has been correlated to mood alterations, metabolic dysfunctions, and poor cognition. To decipher the brain mechanisms underlying these alterations, fundamental research has been conducted using animal models, principally of nocturnal nature (e.g., mice). Nevertheless, because of the diurnal nature of human physiology, it is also important to find and propose diurnal animal models for the study of the light effects in circadian biology. The present review provides an overview of the effects of light at nighttime on physiology and behavior in diurnal mammals, including humans. Knowing how the brain reacts to artificial light exposure, using diurnal rodent models, is fundamental for the development of new strategies in human health based in circadian biology.

https://www.mdpi.com/2624-5175/3/2/14/htm

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Abstract

Background

Understanding factors impacting deaths from COVID‐19 is of the highest priority. Seasonal variation in environmental meteorological conditions affects the incidence of many infectious diseases and may also affect COVID‐19. Ultraviolet A (UVA) radiation induces release of cutaneous photolabile nitric oxide (NO) impacting the cardiovascular system and metabolic syndrome, both COVID‐19 risk factors. NO also inhibits the replication of SARS‐CoV2.

Objectives

To investigate the relationship between ambient UVA radiation and COVID‐19 deaths.

Methods

COVID‐19 deaths at the county level, across the USA, were modelled in a Zero Inflated Negative Binomial model with a random effect for States adjusting for confounding by demographic, socioeconomic and long‐term environmental variables. Only areas where UVB was too low to be inducing significant cutaneous vitamin D3 synthesis were modelled. We used satellite‐derived estimates of UVA, UVB and temperature and relative humidity. Replication models were undertaken using comparable data for England and Italy.

Results

The Mortality Risk Ratio (MRR), in the USA, falls by 29% (40% ‐15% (95% CI)) per 100 (KJ/m²) increase in mean daily UVA. We replicate this in independent studies in Italy and England and estimate a pooled decline in MRR of 32% (48%‐12%) per 100 KJ/m² across the three studies.

Conclusions

Our analysis suggests that higher ambient UVA exposure is associated with lower COVID‐19 specific mortality. Further research on the mechanism may indicate novel treatments. Optimised UVA exposure may have population health benefits.

The post Ultraviolet A Radiation and COVID‐19 Deaths in the USA with replication studies in England and Italy appeared first on EMFSA.

Alexander Wunsch, MD, Wismar University of Applied Sciences, Germany gives a historical perspective on sunlight exposure and explains how both the public’s and medical community’s perspective has changed over time. Recorded on 12/09/2014. [3/2015] [Show ID: 29076] Please Note: Knowledge about health and medicine is constantly evolving. This information may become out of date. More from: Vitamin D for Public Health – Integrating Sunshine, Supplements and Measurement for Optimal Health 2014 (https://www.uctv.tv/vitamin-d-public-…​)

The post Why the Sun is Necessary for Optimal Health appeared first on EMFSA.

Abstract

The recent worldwide rise in idiopathic immune and inflammatory diseases such as multiple sclerosis (MS) and inflammatory bowel diseases (IBD) has been linked to Western society-based changes in lifestyle and environment. These include decreased exposure to sunlight/UVB light and subsequent impairment in the production of vitamin D, as well as dysbiotic changes in the makeup of the gut microbiome. Despite their association, it is unclear if there are any direct links between UVB light and the gut microbiome. In this study we investigated whether exposing the skin to Narrow Band Ultraviolet B (NB-UVB) light to increase serum vitamin D levels would also modulate the makeup of the human intestinal microbiota. The effects of NB-UVB light were studied in a clinical pilot study using a healthy human female cohort (n = 21). Participants were divided into those that took vitamin D supplements throughout the winter prior to the start of the study (VDS+) and those who did not (VDS−). After three NB-UVB light exposures within the same week, the serum 25(OH)D levels of participants increased on average 7.3 nmol/L. The serum response was negatively correlated to the starting 25-hydroxy vitamin D [25(OH)D] serum concentration. Fecal microbiota composition analysis using 16S rRNA sequencing showed that exposure to NB-UVB significantly increased alpha and beta diversity in the VDS− group whereas there were no changes in the VDS+ group. Bacteria from several families were enriched in the VDS− group after the UVB exposures according to a Linear Discriminant Analysis (LDA) prediction, including Lachnospiracheae, Rikenellaceae, Desulfobacteraceae, Clostridiales vadinBB60 group, Clostridia Family XIII, Coriobacteriaceae, Marinifilaceae, and Ruminococcus. The serum 25(OH)D concentrations showed a correlation with the relative abundance of the Lachnospiraceae, specifically members of the Lachnopsira and Fusicatenibacter genera. This is the first study to show that humans with low 25(OH)D serum levels display overt changes in their intestinal microbiome in response to NB-UVB skin exposure and increases in 25(OH)D levels, suggesting the existence of a novel skin-gut axis that could be used to promote intestinal homeostasis and health.

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