Food-chain selenium and human health: emphasis on intake

• Published in: British journal of nutrition 2008-08, Vol.100 (2), p.254-268
• Main Author: Rayman, Margaret P.
• Format: Article
• Language: English
• Subjects: Bioavailability; Biological and medical sciences; Crops; Diet - statistics & numerical data; dietary mineral supplements; dietary minerals; Family medical history; Feeding. Feeding behavior; Food Chain; Food chains; Food Handling - methods; foods; Fruits; functional foods; Functional foods & nutraceuticals; Fundamental and applied biological sciences. Psychology; geographical variation; Health risks; human food chain; human health; human nutrition; Humans; Intake; literature reviews; mineral content; nutrient deficiencies; nutrient excess; nutrient intake; Nutritional Requirements; Nutritional Status; Optimal intake; Selenium; Selenium - administration & dosage; Selenium - analysis; Selenium - deficiency; Selenium - toxicity; Selenium and human health; Selenium in foods; Vegetables; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Wheat
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1017/S0007114508939830

Following the publication of the landmark trial of Clark et al. in 1996 that appeared to show that Se could reduce the risk of cancer, awareness of the importance of Se to human health has markedly increased. As a result, there is now much more aggressive marketing of Se supplements and functional foods, even in situations where additional consumption of Se is inappropriate. The present review addresses how Se gets into the food chain, the wide variability in Se content of foods and the very different levels of intake between countries and regions. Though it is clear that there are adverse consequences for health of both deficient and excessive intake, health effects at intermediate levels of intake are less certain. Thus it is difficult to define optimal intake which depends on a large number of factors, such as which functions of Se are most relevant to a particular disease state, which species of Se is most prominent in the Se source, which health condition is being considered, the adequacy or otherwise of intake of other nutrients, the presence of additional stressors, and lastly whether the ability to make selenoproteins may be compromised. These complexities need to be understood, particularly by policy makers, in order to make informed judgments. Potential solutions for increasing Se intake, where required, include agronomic biofortification and genetic biofortification or, for individuals, increased intake of naturally Se-rich foods, functional foods or supplements. The difficulties of balancing the risks and benefits in relation to Se intake are highlighted.