"New research study published in a peer-reviewed publication Nutrition indicates that selenium may be linked to higher cholesterol readings in those who supplement. This one may push it over the edge for me on taking selenium supplements . . .
Scientists at the University of Warwick Medical School said consuming too much selenium can have adverse effects. While it has strong antioxidant properties, and the above-mentioned perception that it can reduce cancer risks, there is now an apparently legitimate concern that higher quantities of selenium found in some supplements may be a bad thing.
The scientists reached this conclusion after examining the relationship between plasma selenium concentrations (levels of selenium in the blood) with blood lipids (fats in the blood). A cross-sectional study of the1042 participants in the 2000-2001 National Diet and Nutrition Survey (United Kingdom) revealed that among those with higher plasma selenium (more than 1.20 µmol/L) there was an increase in the average total cholesterol level of 8 per cent (0.39 mmol/L (i.e. 15.1 mg/dL). Researchers also found a 10 per cent increase in non-HDL cholesterol levels, which is the bad cholesterol most closely linked to heart disease."
"MedWire News: High levels of selenium in the blood may worsen prostate cancer in some men who already have the disease, results of a US study suggest.
In recent years, selenium supplements have been promoted as a means of preventing prostate cancer, largely based on observational studies that found higher prostate cancer incidence and mortality in geographical areas that are naturally low in selenium, compared with in those that are naturally high in the mineral.
However, the current research findings suggest that "if you already have prostate cancer, it may be a bad thing to take selenium," said study researcher Dr Philip Kantoff, from the Dana-Farber Cancer Institute in Boston, Massachusetts, USA."
Plasma selenium, manganese superoxide dismutase, and intermediate- or high-risk prostate cancer.
Chan JM, Oh WK, Xie W, Regan MM, Stampfer MJ, King IB, Abe M, Kantoff PW.
J Clin Oncol. 2009 Aug 1;27(22):3577-83. Epub 2009 Jun 15.
PMID: 19528373
DOI: 10.1200/JCO.2008.18.8938
Conclusion: These data suggest that the relationship between circulating selenium levels at diagnosis and prognostic risk of prostate cancer is modified by SOD2 genotype and indicate caution against broad use of selenium supplementation for men with prostate cancer.
"High serum selenium associated with elevated LDL and total cholesterol
By Helen Albert
21 January 2010
Atherosclerosis 2009; Advance online publication
MedWire News: High levels of serum selenium are associated with elevated total and low-density lipoprotein (LDL) cholesterol, report US researchers.
The results add weight to those of a previous UK study, reported by MedWire News, that reported an association between high plasma selenium and an adverse lipid profile.
Eliseo Guallar (Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland) and colleagues carried out a cross-sectional analysis of 1159 individuals aged 56.8 years on average who participated in the National Health and Nutrition Examination Survey (NHANES) 2003-2004."
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.
Bleys J, Navas-Acien A, Guallar E.
Selenium and Diabetes: More Bad News for Supplements.
Ann Intern Med. 2007 Jul 9; [Epub ahead of print]
PMID: 17620657 [PubMed - as supplied by publisher]
Stranges S, Marshall JR, Natarajan R, Donahue RP, Trevisan M, Combs GF, Cappuccio FP, Ceriello A, Reid ME.
Effects of Long-Term Selenium Supplementation on the Incidence of Type 2 Diabetes: A Randomized Trial.
Ann Intern Med. 2007 Jul 9; [Epub ahead of
Alteration of natural killer cell-mediated cytotoxicity in rats treated with selenium, diethylnitrosamine and ethylnitrosourea.
Talcott PA, Exon JH, Koller LD.
Cancer Lett. 1984 Jul;23(3):313-22.
PMID: 6611196
Selenium and immunocompetence in patients with head and neck cancer.
Kiremidjian-Schumacher L, Roy M, Glickman R, Schneider K, Rothstein S, Cooper J, Hochster H, Kim M, Newman R.
Biol Trace Elem Res. 2000 Feb;73(2):97-111.
PMID: 11049203
DOI: 10.1385/BTER:73:2:97
ScienceDaily (Mar. 24, 2009) - Individuals who took a dietary supplement called "factor D", which included selenium, vitamin E, and beta-carotene, continued to have lower gastric cancer and overall mortality 10 years after supplementation ceased compared with individuals who did not take the supplements, according to long-term follow-up data from the randomized, double-blind General Population Nutrition Intervention Trial in Linxian, China.