Nutrition
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Randomized Controlled Trial
Long-lasting improved amino acid bioavailability associated with protein pulse feeding in hospitalized elderly patients: a randomized controlled trial.
Aging is associated with a blunted anabolic response to dietary intake, possibly related to a decrease in systemically available amino acids (AAs), which in turn may stem from increased splanchnic AA metabolism. Splanchnic sequestration can be saturated by pulse feeding (80% of daily protein intake in a single meal), enabling increased protein synthesis. The aim of this study was to explore whether protein pulse feeding increased postprandial AA concentrations, and if so whether this increase persisted after 6 wk of dietary treatment. ⋯ This study demonstrates that increased postprandial AA bioavailability induced by protein pulse feeding persists after 6 wk (i.e., that there is no metabolic adaptation blunting AA bioavailability).
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Randomized Controlled Trial
Plasma retinol and total carotenes and fracture risk after long-term supplementation with high doses of retinol.
Observational studies suggest that moderate intakes of retinol and increased circulating retinol levels may increase fracture risk. Easy access to supplements, combined with an aging population, makes this a potentially important association. The aim of this study was to investigate plasma retinol and total carotene concentrations in relation to fracture risk after long-term supplementation with retinol and/or beta-carotene in 998 adults between 1990 and 2007. ⋯ This study does not support earlier reports of an increased fracture risk associated with increased plasma retinol concentration. The potential for carotenes to prevent fractures deserves further investigation.