Selenium might prevent cancer but depends on the type
Scientists say selenium might prevent cancer in humans after all, depending on the type of nutrient taken. The findings may explain why selenium studies have shown conflicting results.
Two types of selenium studied for cancer prevention
Researcher findings reported in the ACS' journal Biochemistry looked at two selenium studies - the Nutritional Prevention of Cancer clinical trial and a later study called the Selenium and Vitamin E Cancer Prevention Trial.
Hugh Harris and colleagues noted in the first trial, selenium was shown to reduce the risk of cancer, but in the second no benefit was found.
The researchers found out selenium might help prevent cancer, but it depends on the type used. In the current study, the scientists looked at how two different types, SeMet and MeSeCys, are processed in human lung cancer cells.
SeMet or Selenomethionine is an amino acid found in food that contains selenium and can be taken as a supplement. MeSeCys or Se-methylselenocysteine is a form of supplemental selenium.
The study results showed lung cancer cells process each type of selenium differently. Specifically, MeSeCys killed more lung cancer cells than SeMet did, explaining mixed conflicting results of studies. The study suggests MeSeCys - a type of selenium - could protect from cancer.
"Uptake, Distribution, and Speciation of Selenoamino Acids by Human Cancer Cells: X-ray Absorption and Fluorescence Methods"
Claire M. Weekley, Jade B. Aitken§, Stefan Vogt, Lydia A. Finney, David J. Paterson, Martin D. de Jonge, Daryl L. Howard, Ian F. Musgrave and Hugh H. Harris