No abstract

Lutein may be protective against diseases such as age-related macular degeneration (ARMD). At present, data regarding bioavailability of lutein from various sources are insufficient. Healthy men (n = 10) participated in an intervention study with a crossover design. After a 2-wk washout period during which they consumed a low-carotenoid diet, the men were administered 1 of 4 lutein doses (lutein supplement, lutein ester supplement, spinach, and lutein-enriched egg) for 9 d. All lutein doses provided 6 mg lutein except for the lutein ester dose, which provided 5.5 mg lutein equivalents. Serum samples were collected from fasting subjects on d -14, 1 (baseline), 2, 3, and 10 and analyzed for changes in lutein concentration. Triacylglycerol-rich lipoproteins (TRL) were separated from postprandial blood samples (0-24 h) after the first lutein dose and analyzed for lutein concentration. Subjects completed all 4 treatments of the study in random order. Results from repeated-measures 1-way ANOVA showed that the baseline and dose-adjusted lutein response in serum was significantly higher after egg consumption than after lutein, lutein ester, and spinach consumption on d 10. There was no significant difference in TRL response. In conclusion, the lutein bioavailability from egg is higher than that from other sources such as lutein, lutein ester supplements, and spinach. The lutein bioavailability from lutein, lutein ester supplements, and spinach did not differ. This finding may have implications for dietary recommendations that may decrease the risk of certain diseases, e.g., ARMD.

Background: Observational studies suggest an inverse association between whole-grain (WG) consumption and inflammation. However, evidence from interventional studies is limited, and few studies have included measurements of cell-mediated immunity. Objective: We assessed the effects of diets rich in WGs compared with refined grains (RGs) on immune and inflammatory responses, gut microbiota, and microbial products in healthy adults while maintaining subject body weights. Design: After a 2-wk provided-food run-in period of consuming a Western-style diet, 49 men and 32 postmenopausal women [age range: 40-65 y, body mass index (in kg/m 2 ) ,35] were assigned to consume 1 of 2 provided-food weight-maintenance diets for 6 wk. Results: Compared with the RG group, the WG group had increased plasma total alkyresorcinols (a measure of WG intake) (P , 0.0001), stool weight (P , 0.0001), stool frequency (P = 0.02), and shortchain fatty acid (SCFA) producer Lachnospira [false-discovery rate (FDR)-corrected P = 0.25] but decreased pro-inflammatory Enterobacteriaceae (FDR-corrected P = 0.25). Changes in stool acetate (P = 0.02) and total SCFAs (P = 0.05) were higher in the WG group than in the RG group. A positive association was shown between Lachnospira and acetate (FDR-corrected P = 0.002) or butyrate (FDR-corrected P = 0.005). We also showed that there was a higher percentage of terminal effector memory T cells (P = 0.03) and LPS-stimulated ex vivo production of tumor necrosis factor-a (P = 0.04) in the WG group than in the RG group, which were positively associated with plasma alkylresorcinol concentrations. Conclusion: The short-term consumption of WGs in a weightmaintenance diet increases stool weight and frequency and has modest positive effects on gut microbiota, SCFAs, effector memory T cells, and the acute innate immune response and no effect on other markers of cell-mediated immunity or systemic and gut inflammation. This trial was registered at clinicaltrials.gov as NCT01902394.Am J Clin Nutr 2017;105:635-50.