Older American Women May Especially Benefit from Distributing and Consuming Protein for Decreasing Odds of Functional Limitations.

OBJECTIVES: Protein is a key macronutrient for preserving physical function, but the role of protein intake on functional status may differ in men and women. We sought to examine the associations of daily protein intake and distribution on functional limitations in older American men and women. DESIGN: Cross-sectional. SETTING: Population-based survey. PARTICIPANTS: The analytic sample included 3,976 men and 4,081 women aged ≥60-years from the 2007-2016 waves of the National Health and Nutrition Examination Survey. MEASUREMENTS: Participants reported their ability to perform basic activities of daily living, instrumental activities of daily living, leisure and social activities, lower extremity mobility activities, and general physical tasks. Those reporting difficulty or an inability in completing such functional tasks were considered as having a functional limitation. Protein intake was determined with dietary recalls and participants revealed functional limitations. Protein recommendations of ≥0.80, ≥1.00, and ≥1.50 g/kg/day were used. Based on these cut-points, we also investigated distribution of protein across 4 eating occasions at ≥0.20, ≥0.25, and ≥0.38 g/kg/meal, respectively. RESULTS: Older women meeting each recommendation had decreased odds for functional limitations: 0.55 (95% confidence interval (CI): 0.40-0.75) for ≥0.80 g/kg/day, 0.75 (CI: 0.58-0.97) for ≥1.00 g/kg/day, and 0.72 (CI: 0.55-0.94) for ≥1.5 g/kg/day. No significant associations were observed in older men. Further, older women with protein consumption ≥0.20 g/kg/meal had decreased odds for functional limitations: 0.24 (CI: 0.10-0.61) for 1 occasion, 0.20 (CI: 0.08-0.49) for 2 occasions, 0.16 (CI: 0.07-0.40) for 3 occasions, and 0.12 (CI: 0.04-0.32) for 4 occasions. A similar trend was observed for intake ≥0.25 g/kg/meal: 0.31 (CI: 0.16-0.62) for 2 occasions, 0.30 (CI: 0.14-0.61) for 3 occasions, and 0.31 (CI: 0.12-0.78) for 4 occasions. Women with 1 and 2 eating occasions at ≥0.38 g/kg/meal of protein had 0.66 (CI: 0.48-0.91) and 0.54 (CI: 0.37-0.79) decreased odds for functional limitations, respectively. CONCLUSION: Trials that are powered to detect the effects of protein on functional status in women will help to establish causality.

Determination of organic acids in seven wheat varieties by capillary gas chromatography.

Fresh wheat tops were extracted with acidic 90% ethanol, and the ethanol was evaporated and a portion of the aqueous residue loaded onto DEAE-Sephadex. Organic acids were eluted with pyridinium formate and then lyophilized and the dried residue was derivatized with 1% trimethylchlorosilane in bis(trimethylsilyl)trifluoroacetamide. The acids were then quantitatively determined using capillary gas chromatography and identified using capillary gas chromatography-mass spectrometry. The acidic ethanol extraction of fresh plant tissue was quantitative for all acids except citric while losses in the remaining procedures were controlled by using an internal standard. The ion exchange chromatography made the greatest contribution to experimental error, imposing a minimum loading requirement of 0.1 mumol of each acid for adequate precision. Organic acid profiles were determined for seven wheat cultivars (Triticum aestivum cv Carazinho, Teal, Lance, Warigal, Isis, Maringa, and BH1146) grown on gravel in solution culture for 30 days. Profiles were simple, consisting of only malic, aconitic, and citric acids, with levels of each acid for all varieties falling within the range 2-5 mumol/g fresh tissue. Storage of samples led to a large increase in sampling error and increased the amount of extractable citric acid.