Selenium linked to lower skin cancer risks
Higher blood levels of selenium may reduce the incidence of skin cancer by about 60 per cent, according to a new study from Dutch and Australian researchers.
Writing in Cancer Epidemiology, Biomarkers & Prevention, the researchers report that the mineral was associated with reduced risks of both basal cell carcinoma (BCC) and squamous cell carcinoma (SCC).
On the other hand, blood levels of carotenoids and alpha-tocopherol (vitamin E) were not associated with any influence on skin cancer risks, report the researchers from Queensland Institute of Medical Research, the University of Queensland, and Maastricht University.
In the US, over 1.5 million people are diagnosed with skin cancer every year. According to Cancer Research UK, a charity, over 76,000 cases of skin cancer were documented in 2005 but this is thought to under-represent the problem.
Jolieke van der Pols and her co-workers examined 485 adults randomly samples in from an Australian community. While no relationship between serum carotenoids or alpha-tocopherol levels and the incidence of BCC or SCC was recorded, the researchers noted an association between selenium levels and both forms of cancer.
The highest average selenium levels of between 1.3 and 2.8 micromoles per litre were associated with a 57 per cent reduction in the incidence of BCC, and a 64 per cent reduction in the incidence of SCC, compared to the lowest average selenium levels of between 0.4 and 1.0 micromoles per litre.
“Relatively high serum selenium concentrations are associated with an approximately 60 per cent decrease in subsequent tumour incidence of both BCC and SCC,” wrote the researchers, “whereas serum concentrations of carotenoids or alpha-tocopherol are not associated with later skin cancer incidence.”
Selenium and cance
Selenium is a trace element that occurs naturally in the soil and is absorbed by plants and crops, from where it enters the human food chain – either directly or through consumption of meat and other products from grazing animals.
The mineral is included in between 50 and 100 different proteins in the body, with multifarious roles including building heart muscles and healthy sperm. However, cancer prevention remains one of the major benefits of selenium, and it is the only mineral that qualifies for an FDA-approved qualified health claim for general cancer reduction incidence.
The claim reads: “Selenium may reduce the risk of certain cancers. Some scientific evidence suggests that consumption of selenium may reduce the risk of certain forms of cancer. However, FDA has determined that this evidence is limited and not conclusive.”
To access FDA’s qualified health claim guidance for selenium, click here .
Source: Cancer Epidemiology, Biomarkers & Prevention
2009, Volume 18, Issue 4, Pages 1167-1173
“Serum Antioxidants and Skin Cancer Risk: An 8-Year Community-Based Follow-up Study”
Authors: J.C. van der Pols, M.M. Heinen, M.C. Hughes, T.I. Ibiebele, G.C. Marks, A.C. Green
Multivitamins linked to younger ‘biological age’: Study
The cells of multivitamin users may have a younger biological age than cells from non-users, according to new research from the US.
Researchers led by Honglei Chen, MD, PhD from National Institute of Environmental Health Sciences looked at the length of telomeres, DNA sequences at the end of chromosomes that shorten as cells replicate and age.
The ageing and lifespan of normal, healthy cells are linked to the so-called telomerase shortening mechanism, which limits cells to a fixed number of divisions. During cell replication, the telomeres function by ensuring the cell’s chromosomes do not fuse with each other or rearrange, which can lead to cancer. Elizabeth Blackburn, a telomere pioneer at the University of California San Francisco, likened telomeres to the ends of shoelaces, without which the lace would unravel.
With each replication the telomeres shorten, and when the telomeres are totally consumed, the cells are destroyed (apoptosis). Previous studies have also reported that telomeres are highly susceptible to oxidative stress.
Dr Chen and his co-workers noted that telomere length may therefore be a marker of biological ageing, and that multivitamins may beneficially affect telomere length via modulation of oxidative stress and chronic inflammation.
According to results published in the new issue of the American Journal of Clinical Nutrition, the telomeres of daily multivitamin users may be on average 5.1 per cent longer than in non-users.
“To our knowledge, this was the first epidemiologic study of multivitamin use and telomere length,” wrote Dr Chen and his co-workers. “Regular multivitamin users tend to follow a healthy lifestyle and have a higher intake of micronutrients, which sometimes makes it difficult to interpret epidemiologic observations on multivitamin use.
“Further investigations would be needed to understand the role of multivitamin use and telomere length and its implication in the etiology of chronic diseases.”
Multivitamin use
According to a National Institutes of Health (NIH) State-of-the-Science Panel, half of the American population routinely use dietary supplements, with their annual spend estimated at over $20 billion.
Recent results of the National Health and Nutrition Examination Survey showed that 35 per cent of the US adult population regularly consumes one or more types of multivitamin product (Am. J. Epidemiol., 2004, Vol. 160, Pages 339-349).
New study
Dr Chen and his co-workers analysed multivitamin use and nutrient intakes, as well as telomere length of 586 women aged between 35 and 74 in the Sister Study. A 146-item food-frequency questionnaire was used to determine multivitamin use and nutrient intakes.
Compared to non-multivitamin users, the researchers noted that that telomeres were on average 5.1 per cent longer for daily multivitamin users.
In an attempt to identify specific nutrients that could be behind the observations, a positive relationship between telomere length and intakes of vitamins C and E from foods was observed.
“Whereas the evidence is not sufficient to conclude that these 2 dietary antioxidants mediated the observed relation, the results are consistent with experimental findings that vitamins C and E protect telomeres in vitro,” wrote the researchers.
Being the first study to report such an association, Dr Chen and his co-workers emphasized that the evidence is only preliminary and that additional epidemiologic studies are required to further explore the association. The implications of the findings in terms of ageing and the etiology of chronic diseases should be carefully evaluated.
Source: American Journal of Clinical Nutrition
June 2009, Volume 89, Number 6, Pages 1857-1863, doi:10.3945/ajcn.2008.26986
“Multivitamin use and telomere length in women”
Authors: Q. Xu, C.G. Parks, L.A. DeRoo, R.M. Cawthon, D.P. Sandler, H. Chen
Beauty is more than skin deep…Sunscreen found to generate harmful compounds that promote skin cancer
A team of researchers from the University of California has found that sunscreen can do more harm than good once it soaks into the skin, where it actually promotes the harmful compounds it is meant to protect against.
The research team found that three commonly used ultraviolet (UV) filters — octylmethoxycinnamate, benzophenone 3 and octocrylene — eventually soak into the deeper layers of the skin after their application, leaving the top skin layers vulnerable to sun damage. UV rays absorbed by the skin can generate harmful compounds called reactive oxygen species (ROS), which can cause skin cancer and premature aging. The researchers found that once the filters in sunscreen soak into the lower layers of skin, the filters react with UV light to create more damaging ROS.
The Cal team’s research is the first to indicate that sunscreen filters — intended to protect the skin from the very UV damage they apparently promote — have reacted in such a way.
The researchers found that the filters only become damaging when they are soaked into the skin and another layer of sunscreen is not applied.
“This research confirms what the natural health community has been saying for years: That sunscreens are harmful to your health,” said Mike Adams, a consumer health advocate. “The best sunscreen is actually achieved with a diet high in antioxidants,” he explained. “When you eat berries, superfoods and fresh produce on a regular basis, these natural antioxidants are utilized by your skin to protect you from excessive ultraviolet ray exposure. Sunburns are caused more by poor nutrition than by UV ray exposure.”
The idea that sunscreen prevents cancer is a myth. It’s a myth promoted by a profit-seeking tag-team effort between the cancer industry and the sunscreen industry. The sunscreen industry makes money by selling lotion products that actually contain cancer-causing chemicals. It then donates a portion of that money to the cancer industry through non-profit groups like the American Cancer Society which, in turn, run heart-breaking public service ads urging people to use sunscreen to “prevent cancer.”
The scientific evidence, however, shows quite clearly that sunscreen actually promotes cancer by blocking the body’s absorption of ultraviolet radiation, which produces vitamin D in the skin. Vitamin D, as recent studies have shown, prevents up to 77 of ALL cancers in women (breast cancer, colon cancer, cervical cancer, lung cancer, brain tumors, multiple myeloma… you name it). Meanwhile, the toxic chemical ingredients used in most sunscreen products are actually carcinogenic and have never been safety tested or safety approved by the FDA. They get absorbed right through the skin (a porous organ that absorbs most substances it comes into contact with) and enter the bloodstream.
The benefits of sunscreen are a myth. Proponents say sunscreen prevents sunburn, but in fact, the real cause of sunburn is not merely UV exposure: It is a lack of antioxidant nutrition. Start eating lots of berries and microalgae (spirulina, astaxanthin, blue-green algae, etc.), and you’ll build up an internal sunscreen that will protect your skin from sunburn from the inside out. Sunburn is actually caused by nutritional deficiencies that leave the skin vulnerable to DNA mutations from radiation, but if you boost your nutrition and protect your nervous system with plant-based nutrients, you’ll be naturally resistant to sunburn. The same nutrients, by the way, also protect the optic nerve and eyes from radiation damage. That’s why the consumption of berries and carrots, for example, has historically been associated with healthy eye function. (The same nutrients that protect the eyes also protect the skin.)
If sunscreen is so bad for humans, you might ask, then why do so many doctors recommend using it? This might be hard for you to believe, but it wasn’t too long ago that doctors routinely recommended smoking cigarettes, too. The Journal of the American Medical Association, in fact, ran numerous ads promoting Camels as “recommended by more doctors than any other cigarette!” Doctors talked up the “benefits” of smoking cigarettes, urging people to start smoking in order to improve brain function or even — get this — make their teeth stronger!
The truth is doctors are easily influenced by commercial interests and can be readily convinced to recommend practically any product, no matter how toxic, unhealthy or deadly to consumers. Just look at how many doctors wrote prescriptions for Vioxx, for example, after being visited by a Vioxx drug rep pushing it as a “miracle drug” for joint pain.