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 cancer
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