The plasma proteome is favorably modified by a high protein diet but not by additional resistance training in older adults: A 17-week randomized controlled trial

Abstract

BackgroundThe age-related loss of muscle mass significantly contributes to the development of chronic diseases, loss of mobility and dependency on others, yet could be improved by an optimized lifestyle.ObjectiveThe goal of this randomized controlled trial was to compare the influence of a habitual diet (CON) with either a diet containing the recommended protein intake (RP) or a high protein intake (HP), both with and without strength training, on the plasma proteome in older adults.MethodsOne hundred and thirty-six women and men (65–85 years) were randomly assigned to three intervention groups. CON continued their habitual diet; participants of the HP and RP group consumed either high protein or standard foods. After 6 weeks of dietary intervention, HP and RP groups additionally started a strength training intervention twice per week for 8 weeks. Twenty-four hours dietary recalls were performed every 7–10 days. Body composition was assessed and blood taken. Plasma proteomics were assessed with LC-MS.ResultsParticipants of the HP group doubled their baseline protein intake from 0.80 ± 0.31 to 1.63 ± 0.36 g/kg BW/d; RP increased protein intake from 0.89 ± 0.28 to 1.06 ± 0.26 g/kg BW/d. The CON group kept the protein intake stable throughout the study. Combined exercise and HP initiated notable changes, resulting in a reduction in bodyfat and increased muscle mass. Proteomics analyses revealed 14 significantly affected proteins by HP diet, regulating innate immune system, lipid transport and blood coagulation, yet the additional strength training did not elicit further changes.ConclusionsCombined HP and resistance exercise in healthy older adults seem to induce favorable changes in the body composition. Changes in the plasma proteome due to the high protein diet point to a beneficial impact for the innate immune system, lipid transport and blood coagulation system, all of which are involved in chronic disease development.Clinical trial registrationThe study was registered at ClinicalTrials.gov (NCT04023513).

The plasma proteome of plant-based diets: analyses of 1463 proteins in 50,000 people

“…The functions of many other proteins identified are not well established. CNDP1 is a dipeptidase, and one previous study reported higher CNDP1 in people on high protein diets [48], which would be consistent with our observation of lower CNDP1 in non-meat eaters (not statistically significant in vegans) who generally have lower protein intake. Several of the proteins identified such as ART3, GAS6, THY1 and EGFR are involved in a range of signalling pathways and progression of tumour tissues [49][50][51][52], while other proteins including LAYN and CDHR2 are believed to have roles in cell adhesion [53,54].…”

Plasma Instead of Serum Avoids Critical Confounding of Clinical Metabolomics Studies by Platelets

“…LC-MS/MS analysis was performed using a Dionex Ultimate3000 nanoLC-system (Thermo Fisher Scientific) coupled to the timsTOF Pro mass spectrometer (Bruker) equipped with a captive spray ion source as described previously. ,, Briefly, dried peptide samples were reconstituted in 5 μL of 30% formic acid (FA) containing standard peptides and diluted with 40 μL of loading solvent (97.9% H 2 O, 2% acetonitrile (ACN), 0.05% trifluoroacetic acid). Thereof, 1 μL was injected for LC-MS/MS analysis.…”

Yes, it matters: in contrast to blood plasma, serum metabolomics is confounded by platelets

“…LC-MS/MS analysis was performed as described previously. 12,14,15 Briefly, Dried peptide samples were reconstituted by adding 5 µL of 30 % formic acid (FA) containing four synthetic standard peptides and subsequent dilution with 40 µL of loading solvent (97.9 % H2O, 2 % ACN, 0.05 % trifluoroacetic acid). Thereof, 1 µL was injected into the Dionex Ultimate3000 nanoLC-system (Thermo Fisher Scientific).…”