This English study compared selenium in blood fractions and related antioxidant markers in healthy adults under 65, healthy adults over 65 and institutionalized older patients. Healthy older adults had modestly lower whole blood and plasma selenium than younger adults, and institutionalized older adults had lower values again. The authors attribute the larger drop to illness and reduced food intake rather than ageing itself.
Key numbers
- Plasma selenium, mean (95% CI): 1.20 (1.15 to 1.25) µmol/L under 65 (n = 75); 1.03 (0.94 to 1.12) µmol/L healthy over 65 (n = 28); 0.81 (0.73 to 0.88) µmol/L institutionalized (n = 23) (Table 2, p. 224).
- Whole blood selenium: 1.37, 1.23 and 1.00 µmol/L in the same groups (Table 2, p. 224).
- Platelet selenium did not differ significantly between groups (26.6 to 27.6 nmol/g protein) (Table 2, p. 224).
Methods (brief)
Fasting blood was fractionated into plasma, erythrocytes and platelets. Selenium was measured by hydride-generation atomic absorption spectrophotometry with between-run precision of 4.1 to 5.9%. Groups were compared by analysis of variance with smoking as a covariable.
Evidence fitness
Supports the observation that older people in institutions can have lower selenium status than healthy peers. It does not measure intake and cannot separate the effects of illness, diet and age.
Limitations
Small groups; no dietary data; no reference material results are reported for selenium; sampling dates are not stated.
Related evidence
Update history
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