Postprandial Micronutrient Variability and Bioavailability: An Interventional Meal Study in Young vs. Old Participants.

This study explores age- and time-dependent variations in postprandial micronutrient absorption after a micronutrient-rich intervention meal within the Biomiel (bioavailability of micronutrients in elderly) study. Comprising 43 healthy participants, the study compares young (n = 21; mean age 26.90 years) and old (n = 22; mean age 66.77 years) men and women, analyzing baseline concentrations and six-hour postprandial dynamics of iron (Fe), copper (Cu), zinc (Zn), selenium (Se), iodine (I), free zinc (fZn), vitamin C, retinol, lycopene, ß-carotene, α-tocopherol, and γ-tocopherol, along with 25(OH) vitamin D (quantified only at baseline). Methodologically, quantifications in serum or plasma were performed at baseline and also at 90, 180, 270, and 360 min postprandially. Results reveal higher baseline serum Zn and plasma lycopene concentrations in the young group, whereas Cu, Se, Cu/Zn ratio, 25(OH) vitamin D, α-tocopherol, and γ-tocopherol were higher in old participants. Postprandial variability of Zn, vitamin C, and lycopene showed a strong time-dependency. Age-related differences in postprandial metabolism were observed for Se, Cu, and I. Nevertheless, most of the variance was explained by individuality. Despite some limitations, this study provides insights into postprandial micronutrient metabolism (in serum/plasma), emphasizing the need for further research for a comprehensive understanding of this complex field. Our discoveries offer valuable insights for designing targeted interventions to address and mitigate micronutrient deficiencies in older adults, fostering optimal health and well-being across the lifespan.

Effects of an Omega-3 Supplemented, High-Protein Diet in Combination with Vibration and Resistance Exercise on Muscle Power and Inflammation in Old Adults: A Pilot Randomized Controlled Trial.

BACKGROUND: Inflammaging is considered to drive loss of muscle function. Omega-3 fatty acids exhibit anti-inflammatory properties. Therefore, we examined the effects of eight weeks of vibration and home-based resistance exercise combined with a whey-enriched, omega-3-supplemented diet on muscle power, inflammation and muscle biomarkers in community-dwelling old adults. METHODS: Participants were randomized to either exercise (3x/week, n = 20), exercise + high-protein diet (1.2-1.5 g/kg, n = 20), or exercise + high-protein and omega-3-enriched diet (2.2 g/day, n = 21). Muscle power (watt/m2) and chair rise test (CRT) time (s) were assessed via CRT measured with mechanography. Furthermore, leg strength (kg/m2) and fasting concentrations of inflammatory (interleukin (IL-) 6, IL-10, high-mobility group box-1 (HMGB-1)) and muscle biomarkers (insulin-like growth factor (IGF-) 1, IGF-binding protein-3, myostatin) were assessed. RESULTS: Sixty-one participants (70.6 ± 4.7 years; 47% men) completed the study. According to generalized linear mixed models, a high-protein diet improved leg strength and CRT time. Only IGF-1 increased with additional omega-3. Sex-specific analyses revealed that muscle power, IL-6, IL-6/IL-10 ratio, and HMGB-1 improved significantly in the male high-protein, omega-3-enriched group only. CONCLUSION: Vibration and home-based resistance exercise combined with a high-protein, omega-3-enriched diet increased muscle power and reduced inflammation in old men, but not in old women. While muscle biomarkers remained unchanged, a high-protein diet combined with exercise improved leg strength and CRT time.

New findings of oxidative stress biomarkers in nutritional research.

PURPOSE OF REVIEW: The aim of this article is to present a brief overview of recently published articles assessing oxidative stress markers in nutritional studies. RECENT FINDINGS: Intervention and observational studies were carried out in both, healthy subjects and patients and describe the association of foodstuffs as well as isolated nutrients with biomarkers of oxidative stress. The results from human intervention studies on healthy participants and patients are controversial. Long-term interventions (>8 weeks) seem to be more effective than short-term or single-dose interventions. Results are difficult to compare because not only the methods used, also the assessed biomarkers and outcomes were very diverse. In addition, studies vary in the compounds and doses used, duration, participants and so on. Different biomarkers (damaged molecules together with antioxidants from different compartments) should be assessed to evaluate the true 'redox-status' of an individual and the impact of a nutritional intervention. SUMMARY: Both observational and interventional studies performed in healthy participants and patients show possible beneficial effects of nutrients and foodstuffs by improving oxidative stress markers and antioxidant enzyme activities. Biomarkers should be standardized to allow better comparison of results of antioxidant intervention studies.