5 New Studies prove sunlight and sunbed use in moderation showing distinct benefits
The studies show that melanomas are decreasing in younger groups who follow the moderation rule and use sunbeds -whereas melanomas in older, indoor dwellers who don't use sunbeds are increasing
1. Cutaneous malignant melanoma incidence rates in Norway
JOHAN MOAN1,2, ZIVILE BATURAITE1, MANTAS GRIGALAVICIUS1 & ASTA JUZENIENE1
1Department of Radiation Biology, Institute for Cancer Research, the Norwegian Radium Hospital, Oslo University Hospital, Montebello, Norway, and 2Department of Physics, University of Oslo, Oslo, Norway
The incidence rates of cutaneous malignant melanoma (CMM) increase throughout the world, in spite of introduction of strategies for prevention.
However, a decrease in incidence rates is observed in some countries.
If the reason for this could be found, it might be useful to transfer the knowledge to other fields of medicine.
CMM age-standardized incidence rates in different age groups in Norway were obtained from NORDCAN for the years 1970-1989 and 1990-2009.
Until 1990, the CMM rates increased, but after that time a stabilization or a decrease was observed for young age groups (15-54 years old), while in older generations (>55 years old) the rates continued to increase.
The decreasing CMM pattern in young age groups may be due to changing patterns to sunlight in sunbathing and use of sunbeds.
2. A Review of Evidence that Ultraviolet-B Irradiance and Vitamin D Reduce Risk for Cancer
William B Grant, PhD Director, Sunlight, Nutrition, and Health Research Center,
San Francisco, CA, US. Endocrine Oncology US Endocrinology, 2013;9(1):50-4
The solar ultraviolet-B (UVB)-vitamin D-cancer hypothesis was proposed in 1980 and has been actively investigated since then. The strongest evidence is from ecologic studies that use indices of solar UVB doses with geographic data on cancer incidence and/or mortality rates.
Good evidence also comes from observational studies for breast and colorectal cancer incidence as well as survival rates for several cancers. Laboratory studies have well described the mechanisms whereby vitamin D reduces risk for cancer and increases survival rates after diagnosis.
The hypothesis largely satisfies Hill's criteria for causality for breast and colorectal cancer and moderately satisfies it for several other cancers.
However, only two randomized controlled trials (RCTs) found a reduction in cancer incidence for higher vitamin D3 intake.
Thus, general acceptance of the UVB-vitamin D-cancer hypothesis will probably be delayed until a large-scale RCT supports it.
Occupational studies can also offer evidence of solar UVB's effect on cancer risk.
A recent study used cancer incidence data for 54 occupation categories based on 1.4 million male and 1.36 million female cancer cases for 1961-2005 in the five Nordic countries.
The index for solar UVB irradiance used was incidence of lip cancer less incidence of lung cancer for males.7
This index inversely correlated with both melanoma and non melanoma skin cancer
(NMSC) for males.
This finding is not surprising because sporadic UV irradiance and chronic UVA irradiance are important risk factors for both melanoma and basal-cell carcinoma, whereas chronic sun exposure is not.
3. Sunbed use and cutaneous melanoma in Norway
JOHAN E. MOAN1,2, ZIVILE BATURAITE1, MANTAS GRIGALAVICIUS1 & ASTA JUZENIENE1
© 2013 the Nordic Societies of Public Health DOI: 10.1177/1403494813496601
Incidence rates of cutaneous melanoma (CM) in light skinned people in Norway are among the highest in the world. Sunbed use has increased in Norway since 1980. We will try to elucidate whether there is any correlation between the increase in sunbed use and the CM incidence rates, whether the increase in CM risk is similar for all age groups, and whether the possible difference between young and old persons can inform future healthcare strategies.
The frequency of sunbed use by different age groups in the time period 1980-2011 and incidence rates (1980-2009) of CM at different age groups in Norway were studied. Time in minutes per day spent in front of screen of computers or TVs for boys and girls was also analysed.
The number of sunbed sessions per year in Norway increased throughout the entire period. The number of men and women diagnosed with CM per year, all ages combined, also increased. Sunbed use increased at a similar rate for three age groups (0-19, 20-50, and >50 years old), while the age-adjusted CM incidence rate increased only for the oldest group. Time spent in front of the screen of computers or TVs increased from 1985 to 2005 and is still increasing.
CM incidence is decreasing while sunbed use is increasing in younger age groups. The present data indicate that more work needs to be done before one can know whether the overall health effects of sunbed exposure are positive or negative.
4. No effect of season of birth on risk of type 1 diabetes, cancer, schizophrenia and ischemic heart disease, while some variations may be seen for pneumonia and multiple sclerosis
Susanna við Streym, 1, * Lars Rejnmark, 1 Leif Mosekilde, 1 Peter Vestergaard 1, 2
Vitamin D and Multiple Sclerosistype 1 Diabetes cancer schizophrenia pneumonia myocardial infarction
Dermato-Endocrinology June 2013 http://dx.doi.org/10.4161/derm.22779
The risk of type 1 diabetes (T1DM), infections, cancer, schizophrenia and multiple sclerosis (MS) has been associated with environmental factors including vitamin D status.
Materials and Methods:
Data were obtained from all children born in Denmark in 1940 (n = 72,839), 1977 (n = 89,570), and 1996 (n = 74,015).
Information on contacts to hospitals (1977-2009) was obtained from the National Hospital Discharge Register.
The main exposure variable was season of birth as a proxy variable for vitamin D status (summer: April-September and winter: October-March).
No associations between season of birth and risk of MS were seen in the 1940 cohort or the 1996 cohort.
In the 1977 cohort, there was a borderline statistically significant decreased risk of MS in those born during wintertime compared with those born during summertime (HR = 0.70, 95% CI: 0.47-1.04, p = 0.07).
There were no significant differences within the groups regarding season and risk of T1DM at any age, T1DM before 10 y, infection, any type of cancer, schizophrenia and myocardial infarction.
In the 1977 cohort the risk of pneumonia was significantly lower among those born in the summer compared with the winter at any age (HR 0.91, 95% CI 0.85-0.97, p < 0.01) and at age < 10 y (HR 0.90, 95% CI 0.84-0.97, p < 0.01).
MS and pneumonia in young subjects may be related to season of birth and thus maternal vitamin D exposure. Low sunlight exposure in the winter time leading to low vitamin D levels during pregnancy may be a potential explanation.
5. Novel vitamin D compounds and skin cancer prevention
Wannit Tongkao-on, 1 Clare Gordon-Thomson, 1 Katie M. Dixon, 1 Eric J. Song, 1 Tan Luu, 1 Sally E. Carter, 1 Vanessa B. Sequeira, 1, 2 Vivienne E. Reeve, 3 Rebecca S. Mason 1, *
Dermato-Endocrinology 5:1, 20 - 33; January 1, 2013; © 2013 Landes Bioscience.
1α,25-dihydroxyvitamin D3DNA damage bufalin photocarcinogenesis photoimmune suppression photoprotection skin cancer prevention vitamin D compounds vitamin D photoproducts
As skin cancer is one of the most costly health issues in many countries, particularly in Australia, the possibility that vitamin D compounds might contribute to prevention of this disease is becoming increasingly more attractive to researchers and health communities.
In this article, important epidemiologic, mechanistic and experimental data supporting the chemopreventive potential of several vitamin D-related compounds are explored. Evidence of photoprotection by the active hormone, 1α,25dihydroxyvitamin D3, as well as a derivative of an over-irradiation product, lumisterol, a fluorinated analog and bufalin, a potential vitamin D-like compound, are provided.
The aim of this article is to understand how vitamin D compounds contribute to UV adaptation and potentially, skin cancer prevention.