Publicaciones H&NS

Rebello, C. J., Johnson, W. D., Martin, C., Johnson, J., . . . Greenway, F. L. (2018). Effect of two oat-based cereal on subjective ratings of appetite. Current Topics in Nutraceutical Research, 16, 113-120.

Abstract

Viscosity generated by oat β-glucan induces gastrointestinal mechanisms that influence appetite. Two oat-based ready-to-eat cereals (RTEC) with similar amounts of β-glucan but differing in their protein and sugar content were compared for their effects on appetite. Forty-seven healthy individuals, ≥18 years old, enrolled in a crossover trial consumed RTEC1 or RTEC2 in random order at least a week apart. Breakfasts contained 250kcals cereal and 105kcals fat-free milk. Subjective ratings of appetite were completed at baseline, and at 30, 60, 120, 180 and 240 minutes after consumption of the breakfast meals. Responses were analyzed as area under the curve (AUC) and per time-point. Significance was set at α=0.05. Fullness (p=0.01) and stomach fullness (p=0.02) were greater with RTEC 1 compared to RTEC 2 at 240 minutes. Stomach fullness (p=0.01) was greater at 30 minutes, and desire to eat (p=0.04) was reduced at 120 minutes with RTEC2 compared to RTEC1. There was no difference in the AUC for hunger, fullness, stomach fullness, desire to eat, or prospective intake. Ready-to-eat cereals containing similar amounts of oat β-glucan differed in the timing of significant differences in fullness or desire to eat, but appetite ratings over a four hour period did not differ.

AlHasawi, F. M., Fondaco, D., Corradini, M. G., Ludescher, R. D., . . . Rogers, M. A. (2018). Gastric viscosity and sugar bioaccessibility of instant and steel cut oat/milk protein blends. Food Hydrocolloids, 82, 424-433. doi:10.1016/j.foodhyd.2018.04.014

Abstract

Milk protein concentrate (MPC; 0 g, 5 g, and 10 g) was added to two commercially available oat products (instant oats and steel cut oats) to examine how MPC addition, and consequent changes in meal formulation, manipulates both gastric lumen viscosity and intestinal carbohydrate-digestion kinetics, in vitro. We used the TNO Intestinal Model-1 (TIM-1) to simulate gastrointestinal digestion of the oats-based meals. Meals containing 5 g or 10 g MPC yielded significantly less total bioaccessible sugar compared with those containing 0 g MPC, while the rate of starch digestion was significantly higher in meals containing 5 g or 10 g MPC. The TIM-1 was coupled with fluorescence spectroscopy and a luminescent molecular rotor to report changes in gastric viscosity in situ, showing that the gastric viscosity was higher in the meals containing MPC. Those findings suggest that MPC in oats-based meals significantly modifies the kinetics of carbohydrate digestion and increases gastric viscosity.

Kock, L. B., Brummer, Y., Exley, T., Rhymer, C., . . . Bordenave, N. (2018). In vitro assessment of oat β-glucans nutritional properties: An inter-laboratory methodology evaluation. Carbohydrate Polymers, 200, 271-277. doi:10.1016/j.carbpol.2018.07.082

Abstract

The purpose of this inter-laboratory study was to test the repeatability and reproducibility of an in vitro method aimed at analyzing the physicochemical properties under physiological conditions of β-glucans from foods. After evaluating β-glucans molar mass and quantification methods using five β-glucan controls, four laboratories ran six oat-based products through in vitro digestion, measured β-glucans solubility and viscosity and molar mass of solubilized β-glucans. The determination of the molar mass of β-glucan controls, their viscosity in solution and β-glucans content in food samples exhibited relative standard reproducibility of 20.9–40.9%, 10.2–40.9% and 2.3–14.8%, respectively. After in vitro digestion, relative standard reproducibility ranged 12.1–60.0%, 12.2–64.3% and 9.7–36.3% for molar mass of extracted β-glucans, their viscosity and their solubility, respectively. Although the characterization methods were satisfactory within the limits of current technology, the in vitro extraction contributed significantly to the uncertainty of final characterization.

Devries, M. C., McGlory, C., Bolster, D. R., Kamil, A., . . . Phillips, S. M. (2018). Leucine, not total protein, content of a supplement is the primary determinant of muscle protein anabolic responses in healthy older women. The Journal of Nutrition, 148(7), 1088-1095. doi:10.1093/jn/nxy091

Abstract

Background: Older adults show a blunted muscle protein synthesis (MPS) response to postprandial hyperaminoacidemia relative to younger adults. Evidence suggests that this anabolic resistance can be overcome by consuming greater quantities of leucine. Objective: The purpose of this trial was to determine whether the addition of leucine to a smaller dose (10 g) of milk proteins would, when compared with a larger dose (25 g) of whey protein isolate (WPI), result in similar increases in acute (hourly) and integrated (daily) myofibrillar protein synthesis (myoPS). Methods: Healthy older (mean ± SD age: 69 ± 1 y) women (n = 11/group) were randomly assigned with the use of a single-blind, parallel-group design to twice-daily consumption of either WPI [25 g WPI (3 g L-leucine)] or leucine (LEU; 10 g milk protein with 3 g total L-leucine) for 6 d. Participants performed unilateral resistance exercise to allow assessment of the impact of the supplement alone and with resistance exercise. We determined acute (13C6-phenylanine) and integrated [using deuterated water (D2O)] rates of myoPS in the fasting (acute), basal (integrated), nonexercised, and exercised states. Results: Acute myoPS increased in both legs in response to LEU (fed: 45%; fed+exercise: 71%; P < 0.001) and WPI (fed: 29%; fed+exercise: 47%; P < 0.001) compared with fasting; the increase was greater with LEU than with WPI in the exercised leg (46%; P = 0.04) but not in the rested leg (P = 0.07). The acute myoPS response was greater in the exercised leg than in the rested leg for both WPI (63%) and LEU (58%) (P < 0.001). Integrated myoPS increased with WPI and LEU in the exercised leg (both 9%; P < 0.001) during supplementation, and with WPI (3%; P = 0.02) but not LEU (2%, P = 0.1) in the rested leg compared with the basal state. Conclusions: A lower-protein (10 compared with 25 g/dose), leucine-matched beverage induced similar increases in acute and integrated myoPS in healthy older women. Lower-protein supplements with added leucine may represent an advantageous approach in older adults to maintain skeletal muscle anabolic sensitivity and attenuate muscle loss; however, further work is needed using longer-term interventions to substantiate these findings. This trial was registered at www.clinicaltrials.gov as NCT02282566.

DellaValle, D. M., Malek, A. M., Hunt, K. J., Peter, J. V., . . . Marriott, B. P. (2018). Low-calorie sweeteners in foods, beverages, and food and beverage additions: NHANES 2007-2012. Current Developments in Nutrition, 2(12). doi:10.1093/cdn/nzy024

Abstract

Background: Most publications about low-calorie sweeteners (LCSs) focus on person-level intake prevalence. Objective: We assessed LCS distribution in foods, beverages, and food and beverage additions (FBAs), e.g., mayonnaise, in the US adult diet as reported in the NHANES (2007-2012). Methods: Dietary items reported in the first 24-h recall were coded for LCS and/or nutritive sweeteners (NSs) with the use of USDA What We Eat in America food files. We calculated the number of times items were reported and LCS/NS content. Results: Of reported items, 56.1% were foods, 29.1% were beverages, and 14.8% were FBAs. LCS was contained in 0.7% of foods, 8.1% of beverages, and 10.4% of FBAs. This food-level analysis identified FBAs as a significant source of LCSs in the US diet. Conclusion: Identifying the diversity of LCS and NS sources will enhance exposure classification for examining diet and health relations, including body weight management.

Marriott, B. P., Hunt, K. J., Malek, A. M., St. Peter, J. V., & Greenberg, D. (2018). Low-calorie sweeteners: Exploring underutilized database resources to understand dietary patterns and obesity. Obesity, 26, S5-S8. doi:10.1002/oby.22261

Abstract

The use and impact of low-calorie sweeteners (LCS) in relation to the national challenges of overweight and obesity are complex and controversial. Most research on LCS have focused on the prevalence of consumption of LCS in beverages. The 2015 Dietary Guidelines Advisory Committee emphasized dietary patterns and health rather than a focus on specific nutrients or foods. The committee took this approach to shift the national emphasis onto the context of total rather than individual nutrient consumption. A broader research paradigm is needed to elucidate the actual exposure to LCS and how they are consumed within dietary patterns in the US population. National-level databases exist that can be used to broaden scientific understanding of the effects of LCS and health outcomes. These databases are underutilized, and they provide potential tools for grasping a fuller picture of LCS in the US diet.

Wilson, T. J., Gray, M. J., Van Klinken, J.W., Kaczmarczyk, M., & Foxe, J. J. (2018). Macronutrient composition of a morning meal and the maintenance of attention throughout the morning. Nutritional Neuroscience, 21(10), 729-743. doi:10.1080/1028415X.2017.1347998

Abstract

Background: At present, the impact of macronutrient composition and nutrient intake on sustained attention in adults is unclear, although some prior work suggests that nutritive interventions that engender slow, steady glucose availability support sustained attention after consumption. A separate line of evidence suggests that nutrient consumption may alter electroencephalographic markers of neurophysiological activity, including neural oscillations in the alpha-band (8–14 Hz), which are known to be richly interconnected with the allocation of attention. It is here investigated whether morning ingestion of foodstuffs with differing macronutrient compositions might differentially impact the allocation of sustained attention throughout the day as indexed by both behavior and the deployment of attention-related alpha-band activity. Methods: Twenty-four adult participants were recruited into a three-day study with a cross-over design that employed a previously validated sustained attention task (the Spatial CTET). On each experimental day, subjects consumed one of three breakfasts with differing carbohydrate availabilities (oatmeal, cornflakes, and water) and completed blocks of the Spatial CTET throughout the morning while behavioral performance, subjective metrics of hunger/fullness, and electroencephalographic (EEG) measurements of alpha oscillatory activity were recorded. Results: Although behavior and electrophysiological metrics changed over the course of the day, no differences in their trajectories were observed as a function of breakfast condition. However, subjective metrics of hunger/fullness revealed that caloric interventions (oatmeal and cornflakes) reduced hunger across the experimental day with respect to the non-caloric, volume-matched control (water). Yet, no differences in hunger/fullness were observed between the oatmeal and cornflakes interventions.Conclusion: Observation of a relationship between macronutrient intervention and sustained attention (if one exists) will require further standardization of empirical investigations to aid in the synthesis and replicability of results. In addition, continued implementation of neurophysiological markers in this domain is encouraged, as they often produce nuanced insight into cognition even in the absence of overt behavioral changes.

Moser, S., Aragon, I., Furrer, A., Van Klinken, J. W., . . . Ferruzzi, M. G. (2018). Potato phenolics impact starch digestion and glucose transport in model systems but translation to phenolic rich potato chips results in only modest modification of glycemic response in humans. Nutrition Research, 52, 57-70. doi:10.1016/j.nutres.2018.02.001

Abstract

Beneficial effects of some phenolic compounds in modulation of carbohydrate digestion and glycemic response have been reported, however effects of phenolics from processed potato products on these endpoints are not well known. The aims of this study were to characterize phenolic profiles of fresh potatoes (purple, red, or white fleshed; 2 varieties each) and chips, and to examine the potential for potato phenolic extracts (PPE) to modulate starch digestion and intestinal glucose transport in model systems. Following in vitro assessment, a pilot clinical study (n=11) assessed differences in glycemic response and gastric emptying between chips from pigmented and white potatoes. We hypothesized that phenolics from pigmented potato chips would be recovered through processing and result in a reduced acute glycemic response in humans relative to chips made from white potatoes. PPEs were rich in anthocyanins (~98, 11 and ND mg/100 g dw) and chlorogenic acids (~519, 425 and 157 mg/100 g dw) for purple, red and white varieties respectively. While no significant effects were observed on starch digestion by α-amylase and the α-glucosidases, PPEs significantly (p<0.05) decreased the rate of glucose transport, measured following transport of 1,2,3,4,5,6,6-d7 -glucose (d7-glu) across Caco-2 human intestinal cell monolayers, by 4.5-83.9%. Consistent with in vitro results, consumption of purple potato chips modestly but significantly (p<0.05) decreased blood glucose at 30 and 60 minutes post consumption compared to white chips without impacting gastric emptying. These results suggest that potato phenolics may play a modest role in modulation of glycemic response and these effects may result in subtle differences between consumer products.

Devries, M. C., McGlory, C., Bolster, D. R., Kamil, A., . . . Phillips, S. M. (2018). Protein leucine content is a determinant of shorter-and longer-term muscle protein synthetic responses at rest and following resistance exercise in healthy older women: A randomized, controlled trial. American Journal of Clinical Nutrition, 107(2), 217-226. doi:10.1093/ajcn/nqx028

Abstract:

Background: Older women may not be consuming enough protein to maintain muscle mass. Augmentation of protein intake with leucine may enhance the muscle protein synthetic response in older women to aid in maintaining muscle mass. Objective: We measured the acute (hourly) and integrated (daily) myofibrillar protein synthesis (myoPS) response to consumption of a high-quality mixed protein beverage compared with an isonitrogenous protein beverage with added leucine. Design: In a parallel design, free-living, healthy older women (aged 65–75 y, n = 11/group) consumed a fixed, weight-maintaining diet with protein at 1.0 g · kg–1 · d–1 and were randomly assigned to twice-daily consumption of either 15 g milk protein beverage containing 4.2 g leucine (LEU) or 15 g mixed protein (milk and soy) beverage containing 1.3 g leucine (CON). Unilateral leg resistance exercise allowed a determination of acute ([13C6]-phenylalanine infusion, hourly rate) and integrated (deuterated water ingestion, daily rate) exercised and rested myoPS responses. Results: Acute myoPS increased in response to feeding in the rested (CON: 13% ± 4%; LEU: 53% ± 5%) and exercised (CON: 30% ± 4%; LEU: 87% ± 7%) leg in both groups, but the increase was greater in LEU (P < 0.001). Integrated myoPS increased during the supplementation period in both legs (rested: 9% ±1%; exercised: 17% ± 2%; P < 0.001) in LEU, but in the exercised leg only (7% ± 2%; P < 0.001) in CON. Conclusions: A 15-g protein-containing beverage with ∼4 g leucine induced greater increases in acute and integrated myoPS than did an isonitrogenous, isoenergetic mixed-protein beverage. Declines in muscle mass in older women may be attenuated with habitual twice-daily consumption of a protein beverage providing 15 g protein and higher (4.2 g/serving) amounts of leucine. This trial was registered at clinicaltrials.gov as NCT02282566.

Pasman, W. J., Hendriks, H. F. J., Minekus, M. M., de Ligt, R. A. F., . . . Bellmann, S. (2018). Subjective feelings of appetite of wholegrain breakfasts evaluated under controlled, laboratory and ‘at home’ conditions. Physiology and Behavior, 194, 285-291. doi:10.1016/j.physbeh.2018.06.024

Abstract

Background: Appetite regulating properties of foods are usually investigated under laboratory conditions, whereas in real life, foods are consumed under at home conditions. The objective of this study was to compare the acute effects of breakfasts when tested in a laboratory condition and in an at home condition. Appetite regulating properties of two bread breakfasts and two cereal breakfasts were also compared. Subjects and methods: In this randomized cross-over trial balanced for laboratory and at home test conditions, thirty-two women consumed five breakfasts, i.e. two bread breakfasts, two cereal breakfasts and one fried-egg breakfast. Visual analogue scales for measuring appetite were captured via an on-line scoring system and were analyzed as incremental area under the curve, as satiation phase and as satiety phase. Results: Location effects were limited to two small effects only. An overall location effect in hunger feelings was observed (p = 0.040), which occurred specifically during the short satiation period (p = 0.0002) where hunger feelings scored higher under laboratory conditions. Similarly, a location effect was observed for desire to eat (p = 0.001); this was again higher under laboratory conditions. No other location effects were observed. Bread breakfasts did not differ in their appetite regulating properties. The Steel Cut oatmeal breakfast was reported to be more satiating (p = 0.001) as compared to the ready-to-eat cereal. Conclusions: Whereas the five breakfasts varied somewhat in their appetite regulating properties, evaluation under laboratory conditions overall did not result in different appetite scores compared to the at home conditions. This suggests that at home testing may be a useful alternative to laboratory test conditions for nutrition research.

Mukherjee, A., Dutta, S., Goyal, T. M., Marwaha, A., & Kapoor, A. (2018). Survey of fruits, vegetables & juice intake of school children, nutritionists & dieticians. Academic Foundation, 1-53.

Musa-Veloso, K., Poon, T., Harkness, L. S., O'Shea, M., & Chu, Y. (2018). The effects of whole-grain compared with refined wheat, rice, and rye on the postprandial blood glucose response: A systematic review and meta-analysis of randomized controlled trials. American Journal of Clinical Nutrition, 108(4), 759-774. doi:10.1093/ajcn/nqy112

Abstract:

Background: Whole grains are often referred to collectively, despite differences in their composition, physical structure, processing, and potential health benefits. Objective: The aim of this study was to compare the postprandial blood glucose response of whole-grain with refined wheat, rice, or rye, while controlling for the food delivery matrix and the processing of the grain (e.g., grinding, germination). Design: Eleven electronic databases were systematically searched to identify studies published up to and including November 2017. Randomized controlled trials comparing the effects of whole-grain wheat, rice, or rye with those of each grain's refined counterpart on postprandial blood glucose area under the curve (AUC) were included. Pooled effect sizes were computed by using the difference in the blood glucose AUC after the consumption of the whole compared with the refined grain. Results: Twenty publications were included, with 10, 14, and 5 strata (or active-control comparisons) on whole-grain wheat, rice, and rye, respectively. The consumption of ground (wholemeal) wheat, compared with white wheat, was not associated with a significant reduction in blood glucose AUC (−6.7 mmol/L ⋅ min; 95% CI: −25.1, 11.7 mmol/L ⋅ min; P = 0.477). The consumption of wholemeal rye, compared with endosperm rye, was not associated with a significant reduction in blood glucose AUC (−5.5 mmol/L ⋅ min; 95% CI: −24.8, 13.8 mmol/L ⋅ min; P = 0.576). The consumption of intact (whole-grain) rice, compared with white rice, was associated with a significant reduction in blood glucose AUC (−40.5 mmol/L ⋅ min; 95% CI: −59.6, −21.3 mmol/L ⋅ min; P < 0.001). Conclusions: Compared with white rice, whole-grain rice significantly attenuates the postprandial blood glucose response. In most of the studies on wheat and rye, the postprandial blood glucose responses to foods formulated with wholemeal compared with refined flours were compared. Whether reductions in the blood glucose AUC can be achieved with whole-grain (as opposed to wholemeal) wheat and rye requires further investigation.

Stachenfeld, N. S., Leone, C. A., Mitchell, E. S., Freese, E., & Harkness, L. (2018). Water intake reverses dehydration associated impaired executive function in healthy young women. Physiology and Behavior, 185, 103-111. doi:10.1016/j.physbeh.2017.12.028

Abstract:

Introduction: Healthy women do not always consume Recommended Daily Levels of fluid intake ad libitum. We hypothesized that 1) women lose ≥ 1.0% BW during daily activities, 2) that mild body water loss impairs memory and executive function, 3) water intake to recommended daily levels will improve cognitive function. Methods: We tested 12 women (26 ± 5 yr, 22.5 ± 2.6 kg/m2 BMI). Session 1 was a control (CON) session, during which subjects monitored their food and fluid intake (diary) and activity (Fitbit®). The next two sessions were applied in balanced order: dehydration (DEH) session, where subjects minimized drinking, and a euhydration (EUH) session, where subjects drank Recommended Daily Levels of fluid for their age and sex, or 2500 ml/24 h. We compared emotion, sensory perception and cognition with computer based visual analog tests and computer based cognitive tasks (Cogstate) at 5 PM, i.e. baseline (BL) on the evening prior to the session, and at 7 AM, 12 PM, and 5 PM during the session. Results: Urine specific gravity (USG) was similar at BL across conditions (CON 1.013 ± 0.002, DEH 1.015 ± 0.002, EUH 1.014 ± 0.002) and increased with dehydration (CON 1.011 ± 0.003, DEH 1.021 ± 0.002, EUH 1.010 ± 0.002, P < 0.05) by 5 PM of the session. Uncontrolled fluid intake and physical activity were similar across sessions. The water challenges did not impact Detection, Identification, One-Card Learning, but EUH improved visual and working memory (Groton Maze Learning Test) errors: CON 40.1 ± 11.1, DEH 40.5 ± 10.1, EUH 33.9 ± 10.9, P < 0.05. Executive function [Set Shifting (SETS)] also improved under EUH, errors: BL 22.5 ± 12.7 vs. 5 PM 17.8 ± 6.2, P < 0.05. Conclusions: Mild dehydration caused deficits in visual and working memory and executive function in healthy young women. These deficits were reversed by drinking water to the European Food Safety Authority and Institute of Medicine requirements of 2.5 l/day for adult women.

Zhang, T., Shao, J., Gao, Y., Chen, C., . . . Ji, L. L. (2017). Absorption and elimination of oat avenanthramides in humans after acute consumption of oat cookies. Oxidative Medicine and Cellular Longevity, 2017, 2056705. doi:10.1155/2017/2056705

Abstract:

Background. Avenanthramides (AVA) are a group of diphenolic acids found only in oats that have anti-inflammatory and antioxidant effects. Absorption of AVAs in humans after oral consumption of natural oat flour is unknown. Objective. To examine the appearance of AVAs in plasma after oral ingestion of oat cookies and estimate key pharmacokinetic parameters. Methods. Male and female nonobese participants (n=16) consumed three cookies made with oat flour containing high (229.6 mg/kg, H-AVA) or low (32.7 mg/kg, L-AVA) amounts of AVAs, including AVA-A, AVA-B, and AVA-C. Blood samples were collected at 0, 0.5, 1, 2, 3, 5, and 10 h after ingestion. Plasma total (conjugated and free) AVA concentrations were quantified using UPLC-MS, and pharmacokinetic parameters for each AVA were estimated. Results. AVAs reached peak concentrations in plasma between 2 and 3 h for the H-AVA group and between 1 and 2 h for the L-AVA group. Maximal plasma concentrations for AVAs were higher in the H-AVA than in the L-AVA group. AVA-B demonstrated a longer half-life and slower elimination rate than AVA-A and AVA-C. Conclusions. AVAs found naturally in oats are absorbed in the plasma after oral administration in humans. AVA-B has the slowest elimination rate and the longest half-life compared to AVA-A and AVA-C, while AVA-C demonstrated the lowest plasma concentrations. 

Earnshaw, S. R., McDade, C. L., Chu, Y., Fleige, L. E., & Sievenpiper, J. L. (2017). Cost-effectiveness of maintaining daily intake of oat β-glucan for coronary heart disease primary prevention. Clinical Therapeutics, 39(4), 804-818.e3. doi:10.1016/j.clinthera.2017.02.012

Abstract:

Purpose Oat β-glucan reduces cholesterol levels and thus reduces the risk for coronary heart disease (CHD). However, its economic impact has not been well studied. We examined the economic impact of daily intake of ≥3 g of oat β-glucan in primary prevention of CHD in patients receiving statins or no pharmacologic treatment. Methods A decision model was developed to compare costs and outcomes associated with lowering cholesterol levels with no pharmacologic treatment and normal diet, no pharmacologic treatment plus ≥3 g/d of oat β-glucan, and statin therapy plus ≥3 g/d of oat β-glucan. The population comprised men 45, 55, or 65 years of age with no history of cardiovascular disease and a 10-year risk for CHD of 5%, 7.5%, or 10%. Clinical efficacy data were gathered from meta-analyses; safety data, costs, and utilities were gathered from published literature. Cost per quality-adjusted life years and number of first events were reported. Findings Maintaining ≥3 g/d of β-glucan may be cost-effective in men aged 45, 55, and 65 years with 10-year CHD risks of 5.0%, 7.5%, and 10.0% taking no pharmacologic treatment or on statins. It may also reduce first events of myocardial infarction and CHD death. Results are sensitive to oat β-glucan cost but insensitive to changes in other parameters. Maintaining ≥3 g of oat β-glucan daily remains cost-effective within plausible range of values. Implications β-glucan may be cost-effective for preventing CHD events in middle-aged men with no history of cardiovascular events whose 10-year CHD risk is ≥5%. Maintaining daily β-glucan intake may have considerable impact on first events.

Korczak, R., Kamil, A., Fleige, L., Donovan, S. M., & Slavin, J. L. (2017). Dietary fiber and digestive health in children. Nutrition Reviews, 75(4), 241-259. doi:10.1093/nutrit/nuw068

Abstract:

Digestive health is an expanding area in nutrition research due to the interest in how food components such as fiber affect gastrointestinal tolerance, stool form, defecation frequency, transit time, and gut microbial composition and metabolic activity. In children, however, digestive health studies that intervene with dietary fiber are limited due to legal and ethical concerns. To better understand if fiber improves digestive health in children, a literature review was conducted to answer the following research question: What are the effect(s) of fiber-containing foods and/or supplements on digestive health outcomes in children? A search of the PubMed database identified a total of 12 studies that fit the inclusion criteria established for this review. Most of the evidence in children shows beneficial effects of partially hydrolyzed guar gum, glucomannan, and bran on digestive health outcomes; however, the existing evidence is not conclusive. Furthermore, limited data exists on the effect of whole-grain sources of dietary fiber, such as oats. Additional well-designed intervention trials are needed to determine whether outcomes of digestive health such as stool form, gastrointestinal tolerance, and stool frequency are improved by increasing the fiber content of children’s diets with whole-grain sources.

Gulati, S., Misra, A., & Pandey, R. M. (2017). Effects of 3 g of soluble fiber from oats on lipid levels of Asian Indians - A randomized controlled, parallel arm study. Lipids in Health and Disease, 16, 71. doi:10.1186/s12944-017-0460-3

Abstract:

Background Cardiovascular diseases are more prevalent and severe in Asian Indians. Simple diet-based strategies are important for prevention of cardiovascular diseases. The aim of the present study was to evaluate the effects of oats consumption on lipid parameters in mildly hypercholesterolemic Asian Indians living in India. Methods A short-term, prospective, open-labeled, randomized controlled, parallel group study was conducted. Mildly hypercholesterolemic (total cholesterol >200 mg/dL and <240 mg/dL) subjects (n = 80) were randomized into two groups: intervention (n = 40) and usual diet (n = 40). Sample size was calculated for a two-group parallel superiority randomized control trial. Out of 80 enrolled subjects 69 subjects completed the study; 33 in the control group and 36 in the intervention group. In the intervention group, patients were served 70 g of oats twice a day in the form of porridge and upma (A thick porridge from oats with seasonings and vegetables) under observation at the study site. Lipid parameters were assessed at baseline and after 4 weeks of intervention. Results There was a reduction of 3.1% in total cholesterol levels in the control group as against 8.1% reduction in the intervention group (p < 0.02). Greater reductions were also seen in low-density lipoprotein cholesterol in the intervention group (11.6%) as compared to control group (4.1%, p < 0.04) over a period of 28 days. Conclusion Daily consumption of 3 g of soluble fiber from 70 g of oats leads to beneficial effects on the lipid parameters, specifically total cholesterol and low-density lipoprotein cholesterol in hypercholesterolemic Asian Indians. Large scale studies over a longer period of intervention are required to further establish the cholesterol-lowering effect of oat fiber.

AlHasawi, F. M., Fondaco, D., Ben-Elazar, K., Ben-Elazar, S., . . . Rogers, M. A. (2017). In vitro measurements of luminal viscosity and glucose/maltose bioaccessibility for oat bran, instant oats, and steel cut oats. Food Hydrocolloids, 70, 293-303. doi:10.1016/j.foodhyd.2017.04.015

Abstract:

Three commercially available oat products—instant oats, steel cut oats, and oat bran—were studied using the TNO Intestinal Model-1 (TIM-1) coupled with fluorescence spectroscopy and molecular rotors to evaluate carbohydrate digestion and in vitro gastric viscosity as a function of time. A proportional relationship between total bioaccessible sugars and the concentration of available carbohydrates was observed for the different oat-based foods. The rate of starch digestion was greatest for instant oats and lowest for steel cut oats. β-glucan, starch, and total carbohydrate concentrations were proportional to the initial gastric viscosity. Overall, gastric viscosity differed considerably between samples. Instant oat and oat bran viscosities were highest at the onset of digestion and decreased with time, whereas the viscosity of steel cut oats at the onset of digestion was the lowest viscosity observed, increasing with time. These findings suggest that modification of food form and formulation during processing alters sugar bioaccessibility and luminal viscosity.

Turner, J. M., Marsteller, D. A., Luxkaranayagam, A. T., Fletcher, J. M., & Stachenfeld, N. S. (2017). Mild exercise in female subjects impairs complex learning independent of hydration status and emotion. Physiology and Behavior, 180, 113-119. doi:10.1016/j.physbeh.2017.08.013

Abstract:

Introduction Depending on type, intensity and duration, exercise can have both beneficial and detrimental effects on cognitive function. The impact of exercise on learning and memory is also sensitive to hydration status, so we hypothesized that mild hypohydration induced with exercise, will adversely impact executive and complex memory function tasks and that these changes in cognitive function are independent of changes in emotion. Methods Using a cross over design, on separate days 11 women exercised on a recumbent bicycle. On day 1, women exercised to 1.5% hypohydration at 34 °C, and < 10% rh, on day 2, water loss from sweating was replaced by drinking water (euhydration). Pre- and post-euhydration and hypohydration, subjects underwent computer based cognitive tasks (simple, learning, memory, executive function) and visual analog testing to determine emotion. Results Exercise increased Groton Maze Learning Test errors within both conditions: [Pre: 41.5 ± 11.8, Post: 46.8 ± 12.4, and Pre: 41.9 ± 9.2, Post: 46.5 ± 12.9, hypohydrated and euhydrated, respectively, Pre vs Post, ANOVA, time effect, P = 0.007], a test of acquisition, storage, and use of new knowledge. None of the measures of emotion were affected by exercise under either hydration condition.

Conclusions A bout of mild aerobic exercise compromised performance on a complex learning and memory task, but this change was unaffected by hydration status or emotion.

Yang, J., Vittori, N., Wang, W., Shi, Y. C., . . . Pan, Y. (2017). Molecular weight distribution and fermentation of mechanically pre-treated konjac enzymatic hydrolysates. Carbohydrate Polymers, 159, 58-65. doi:10.1016/j.carbpol.2016.12.014

Abstract:

There is interest in novel fibers as potential prebiotics for new and reformulated food products. Two konjac glucomannan (KGM) hydrolysates were developed by enzymatic hydrolysis with (KGMH I) or without (KGMH II) mechanical shear pre-treatment. These were characterized and evaluated as fermentation substrates using five lactobacilli and three bifidobacteria. Enzymatic treatment of native KGM reduced the average molecular weights of supernatant and pellet by ∼3-fold. Additional mechanical shear pre-treatment further reduced supernatant and pellet molecular weights by 5% and 35%, respectively. We postulated that pulverized and depolymerized short-chain KGM would better promote the growth of lactobacilli and bifidobacteria. Most lactobacilli fermented KGM hydrolysates. Lactobacillus acidophilus and Lactobacillus plantarum fermented KGMH I and II better than they fermented inulin. Overall, bifidobacteria were not strong fermenters of KGM hydrolysates. Both pulverization and enzymatic depolymerization significantly affected KGM molecular weight, suggesting that human gastrointestinal bacteria can utilize KGM hydrolysates with reduced weights.