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The n-3 docosapentaenoic acid (n-3 DPA) could be a novel source of n-3 long-chain polyunsaturated fatty acids (LCPUFA) with beneficial physiological effects. Following the supplementation of 0.5% purified n-3 DPA for 3 weeks from weaning, the n-3 DPA content increased in one-half of the 18 studied tissues (from +50% to +110%, p< 0.05) and mostly affected the spleen, lung, heart, liver, and bone marrow. The n-3 DPA was slightly converted into DHA (+20% in affected tissues, p< 0.05) and mostly retroconverted into EPA (35–46% of n-3 DPA intake in liver and kidney) showing an increased content of these LCPUFA in specific tissues. The partial incorporation of dairy lipids in the diet for 6 weeks increased overall n-3 PUFA status and brain DHA status. Furthermore, the n-3 DPA supplementation and dairy lipids had an additive effect on the increase of n-3 PUFA tissue contents. Moreover, n-3 DPA supplementation decreased plasma cholesterol.

The muscle protein synthetic response to food intake is reduced in aging, contributing to a progressive muscle loss. This anabolic resistance results from a decreased sensitivity to anabolic signals, especially leucinemia, a potent activator of protein synthesis. Nutritional strategies are needed to reach the anabolic threshold of leucinemia and stimulate muscle anabolism. This study sought to evaluate the effect of supplementing meals with soluble milk proteins (SMP) on postprandial leucinemia in elders. During 3 successive experimental sessions, 6 healthy older men (66.7 ± 0.7y) consumed a standardized lunch (27 g of proteins; 2.2 g of leucine) supplemented with a beverage containing 0 g, 5 g or 8.2 g of SMP (0 g, 0.6 g and 1.1 g of leucine, respectively). The supplementation with 5 g or 8.2 g of SMP induced an increase of 1.9× and 2.5× in plasma leucine levels, compared to the control meal (without additional SMP). The leucine area under the curve over 3h20 had an increase of 2.1× and 2.3×, respectively, as compared to the control meal. Ingesting SMP in addition to a meal strongly increased postprandial plasma leucine, and could be an effective strategy to reach anabolic thresholds and optimize the anabolic effect of each meal.

Metabolic pools of biological matrices can be extensively analyzed by NMR. Measured data consist of hundreds of NMR signals with different chemical shifts and intensities representing different metabolites’ types and levels, respectively. Relevant predictive NMR signals need to be extracted from the pool using variable selection methods. This paper presents both a review and research on this metabolomics field. After reviews on discriminant potentials and statistical analyses of NMR data in biological fields, the paper presents an original approach to extract a small number of NMR signals in a biological matrix A (BM-A) in order to predict metabolic levels in another biological matrix B (BM-B). Initially, NMR dataset of BM-A was decomposed into several row-column homogeneous blocks using hierarchical cluster analysis (HCA). Then, each block was subjected to a complete set of Jackknifed correspondence analysis (CA) by removing separately each individual (row). Each CA condensed the numerous NMR signals into some principal components (PCs). The different PCs representing the (n – 1) active individuals were used as latent variables in a stepwise multi-linear regression to predict metabolic levels in BM-B. From the built regression model, metabolite level in the outside individual was predicted (for next model validation). From all the PCs-based regression models resulting from all the jackknifed CA applied on all the individuals, the most contributive NMR signals were identified by their highest absolute contributions to PCs. Finally, these selected NMR signals (measured in BMA) were used to build final population and sub-population regression models predicting metabolite levels in BM-B.

Abstract: Nutritional recommendations for the prevention and management of sarcopenia, now defined as a loss of muscle mass and muscle function (strength or performance), has recently been established by expert panels (see Appendix 1 for the prevalence of sarcopenia). It appears that exercise with adequate leucine-rich protein supplementation is necessary to preserve muscle function during ageing. The main commercially available protein source of leucine are native whey proteins directly extracted from milk. Clinical studies performed with native whey proteins* (NWP) have shown that a daily moderate consumption of NWP promoted an increase in postprandial protein anabolism and resistance to fatigue in elderly persons by improving the effect of exercise on muscle function.