Food-chain selenium and human health: spotlight on speciation.
Level 5 - mechanism / opinion, no new human data
Narrative review of biochemical pathways, food speciation, and health effects without systematic methodology.
PubMed 18346307 · doi:10.1017/S0007114508922522
What was done
This narrative review cataloged current knowledge on selenium (Se) chemical species present in foods and dietary supplements, plant biosynthetic pathways of Se assimilation, animal metabolic pathways, analytical identification methods (such as retention-time matching versus mass spectrometry fragmentation), and associated health effects.
What was found
The abstract reports no quantitative values. It reports that organic Se species demonstrate higher bioavailability than inorganic forms. Potent anti-tumor effects are attributed specifically to low-molecular-weight species (Se-methyl-selenocysteine and its gamma-glutamyl derivative) found in Allium and Brassica plants. The authors emphasize that retention-time matching alone provides only tentative identification and requires molecular ion fragmentation for definitive structural confirmation.
Why it matters
Evaluating dietary selenium requirements and health outcomes solely by total elemental selenium intake is insufficient, as bioavailability, biological activity, and toxicity vary substantially across distinct chemical species.
Limits
As a narrative review, it lacks a systematic literature search, formal study selection criteria, or quantitative synthesis. The abstract explicitly highlights significant existing gaps in identifying naturally occurring Se species in food and widespread analytical limitations in prior speciation research.
Cited by
- supports Brazil nuts contain selenium in the form of selenomethionine, whereas animal foods provide selenium in the form of selenocysteine.