High-fiber rye diet increases ileal excretion of energy and macronutrients compared with low-fiber wheat diet independent of meal frequency in ileostomy subjects

Multiple Antioxidative and Bioactive Molecules of Oats (Avena sativa L.) in Human Health

Oats (Avena sativa L.) are rich in protein, fiber, calcium, vitamins (B, C, E, and K), amino acids, and antioxidants (beta-carotene, polyphenols, chlorophyll, and flavonoids). β-glucan and avenanthramides improve the immune system, eliminate harmful substances from the body, reduce blood cholesterol, and help with dietary weight loss by enhancing the lipid profile and breaking down fat in the body. β-glucan regulates insulin secretion, preventing diabetes. Progladins also lower cholesterol levels, suppress the accumulation of triglycerides, reduce blood sugar levels, suppress inflammation, and improve skin health. Saponin-based avanacosidase and functional substances of flavone glycoside improve the immune function, control inflammation, and prevent infiltration in the skin. Moreover, lignin and phytoestrogen prevent hormone-related cancer and improve the quality of life of postmenopausal women. Sprouted oats are rich in saponarin in detoxifying the liver. The literatures have been reviewed and the recent concepts and prospects have been summarized with figures and tables. This review discusses recent trends in research on the functionality of oats rather than their nutritional value with individual immunity for self-medication. The oat and its acting components have been revisited for the future prospect and development of human healthy and functional sources.

Role of the food matrix and digestion on calculation of the actual energy content of food

The energy content of food is calculated on the basis of general factors for fat, protein, and carbohydrates. These general factors were derived by W.O. Atwater in the late 19th century, while additional factors for dietary fiber, polyols, and organic acids were introduced more recently. These factors are applied indiscriminately to all types of foods, yet the same nutrient may be digested to different extents to generate energy, depending on the characteristics of the food matrix, the processing methods applied to foods, and the meal composition. As a consequence, the actual energy content of food may differ from what is theoretically calculated with the Atwater factors. In this review, the relationship of macronutrient digestibility with food structure, macronutrient structure, and food composition is examined, and the implications for the amount of energy achievable through diet are highlighted. Estimates of the discrepancy between calculated energy content and actual energy content are provided for different diets. The findings may have implications for consumer purchasing decisions as well as for the design of dietary interventions.

Dietary intake of whole grains and plasma alkylresorcinol concentrations in relation to changes in anthropometry: the Danish diet, cancer and health cohort study

BACKGROUND/OBJECTIVES

Whole grain intake has been associated with a small but significant lower body weight gain in observational studies, but there is limited knowledge about the associations with specific whole grain types. The objective was to investigate the association between whole grains, different sources of whole grains and biomarkers of whole grain intake (alkylresorcinols) in relation to subsequent changes in waist circumference (WC) and body weight.

SUBJECTS/METHODS

Cohort study of 57 053 participants with baseline information on whole grain intake from questionnaires (FFQ) and biomarkers of whole grain rye and wheat intake, plasma alkylresorcinols, for a subset. WC and body weight were measured at baseline and again at follow-up. The associations were estimated using multiple linear regression analyses and logistic regression.

RESULTS

For women, overall whole grain intake was not related to changes in WC or body weight. For men, total whole grain intake was associated with gains in WC (ΔWC per 25 g increment: 0.44 cm, 95% CI: 0.34 cm; 0.54 cm) and body weight (Δweight per 25 g increment: 150 g, 95% CI: 78 g; 222 g), but the results changed to null or changed direction when adjusting for baseline anthropometry. For the different sources of whole grains, rye (women) and crispbread was significantly associated with gains in WC and body weight. Plasma alkylresorcinol concentration was associated with reduced WC, but not body weight, for women (ΔWC per 50 nmol/l increment: -0.69 cm, 95% CI:-1.26 cm;-0.13 cm), but no association was found for men.

CONCLUSIONS

Overall, no strong relationship between whole grain intake, measured from questionnaires or using biomarkers was found in relation to changes in body weight and WC.

NMR-based metabolomics highlights differences in plasma metabolites in pigs exhibiting diet-induced differences in adiposity

PURPOSE

A better understanding of the control of body fat mass and distribution is required for both human health and animal production. The current study investigates plasma parameters in response to changes in body fat mass.

METHODS

Pigs from two lines divergently selected for residual feed intake were fed diets contrasted in energy sources and nutrients. Between 74 and 132 days of age, pigs (n = 12 by diet and by line) received isoproteic and isoenergetic diets, either rich in starch (LF) or in lipids and fibres (HF). At the end of the feeding trial, plasma samples were analysed by (1)H NMR spectroscopy and standard hormonal and biochemical assays.

RESULTS

Pigs fed the HF diet had lower (P < 0.01) perirenal and subcutaneous adipose tissue relative masses than pigs fed the LF diet. Metabolomic approach showed a clear discrimination between diets, with lower (P < 0.05) plasma levels of creatinine-lysine, creatine, tyrosine, proline, histidine, lysine, phenylalanine and formate but higher (P < 0.001) plasma VLDL-LDL levels in HF pigs than in LF pigs. Plasma concentrations of triglycerides were higher (P < 0.001), while plasma concentrations of β-hydroxybutyrate, leptin, glucose, insulin and urea were lower (P ≤ 0.05) in HF pigs than in LF pigs. Plasma levels of leptin, creatine and urea were positively correlated (r = 0.3, P < 0.05) with relative adipose tissue masses.

CONCLUSION

These data indicate that metabolites associated with energy and protein metabolism were involved in the response to a high-fat, high-fibre diet. Relevant plasma indicators of metabolic flexibility related to changes in body adiposity were then proposed.

Effects of unfermented and fermented whole grain rye crisp breads served as part of a standardized breakfast, on appetite and postprandial glucose and insulin responses: a randomized cross-over trial

BACKGROUND

Whole grain rye products have been shown to increase satiety and elicit lower postprandial insulin response without a corresponding change in glucose response compared with soft refined wheat bread. The underlying mechanisms for these effects have not been fully determined The primary aim of the study was to investigate if whole grain rye crisp bread compared to refined wheat crisp bread, elected beneficial effects on appetite and postprandial insulin response, similarly as for other rye products.

METHODS

In a randomized cross-over trial, 23 healthy volunteers, aged 27-70 years, BMI 18-31.4 kg/m2, were served a standardized breakfast with unfermented whole grain rye crisp bread (uRCB), fermented whole grain rye crisp bread (RCB) or refined wheat crisp bread (WCB), Appetite was measured using a visual analogue scale (VAS) until 4 h after breakfast. Postprandial glucose and insulin were measured at 0-230 min. Breads were chemically characterized including macronutrients, energy, dietary fiber components, and amino acid composition, and microstructure was characterized with light microscopy.

RESULTS

Reported fullness was 16% higher (P<0.001), and hunger 11% and 12% lower (P<0.05) after ingestion of uRCB and RCB, respectively, compared with WCB. Postprandial glucose response did not differ significantly between treatments. Postprandial insulin was 10% lower (P<0.007) between 0-120 min but not significantly lower between 0-230 min for RCB compared with WCB. uRCB induced 13% (P<0.002) and 17% (P<0.001) lower postprandial insulin response between 0-230 min compared with RCB and WCB respectively.

CONCLUSION

Whole grain rye crisp bread induces higher satiety and lower insulin response compared with refined wheat crisp bread. Microstructural characteristics, dietary fiber content and composition are probable contributors to the increased satiety after ingestion of rye crisp breads. Higher insulin secretion after ingestion of RCB and WCB compared with uRCB may be due to differences in fiber content and composition, and higher availability of insulinogenic branched chain amino acids.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02011217.

Microbial degradation of whole-grain complex carbohydrates and impact on short-chain fatty acids and health

Whole-grain cereals have a complex dietary fiber (DF) composition consisting of oligosaccharides (mostly fructans), resistant starch, and nonstarch polysaccharides (NSPs); the most important are arabinoxylans, mixed-linkage β(1,3; 1,4)-d-glucan (β-glucan), and cellulose and the noncarbohydrate polyphenolic ether lignin. The highest concentration of NSPs and lignin is found in the outer cell layers of the grain, and refined flour will consequently be depleted of a large proportion of insoluble DF components. The flow and composition of carbohydrates to the large intestine are directly related to the intake of DF. The type and composition of cereal DF can consequently be used to modulate the microbial composition and activity as well as the production and molar ratios of short-chain fatty acids (SCFAs). Arabinoxylans and β-glucan in whole-grain cereals and cereal ingredients have been shown to augment SCFA production, with the strongest relative effect on butyrate. When arabinoxylans were provided as a concentrate, the effect was only on total SCFA production. Increased SCFA production in the large intestine was shown by the concentration in the portal vein, whereas the impact on the concentration in peripheral blood was less because the majority of propionate and butyrate is cleared in the liver. Active microbial fermentation with increased SCFA production reduced the exposure of potentially toxic compounds to the epithelium, potentially stimulating anorectic hormones and acting as signaling molecules between the gut and the peripheral tissues. The latter can have implications for insulin sensitivity and glucose homeostasis.

Effects of whole grain rye crisp bread for breakfast on appetite and energy intake in a subsequent meal: two randomised controlled trails with different amounts of test foods and breakfast energy content

BACKGROUND

Fibre-rich rye products have been shown to have superior effects on self-reported appetite compared to white wheat bread and some studies have shown lower energy intake after subsequent meal. The aim of the present study was to evaluate the effects of whole grain rye crisp bread (RB) versus refined wheat bread (WB) on appetite in two studies using different portion sizes and total energy intakes.

METHODS

Two randomised cross-over pre-load studies were conducted in 20 and 21 subjects, respectively. Appetite was rated by visual analogue scale (VAS) for 4 h. In both studies, participants were 39 ± 14 years old and had BMI 23 ± 3. The studies differed in terms of energy content of the breakfasts and proportion of energy from the treatment product as well as amount of test products. Differences between treatments within the two studies were evaluated using mixed models with repeated measures appropriate for cross-over designs.

RESULTS

In Study one, hunger and desire to eat were significantly lower (P < 0.05) after RB compared with WB, but there were no difference for fullness or difference in energy intake at lunch served ad libitum. In Study two, the portion size was lower than in Study one and the test product constituted a larger proportion of the breakfast. Fullness was significantly higher after RB compared with WB (P < 0.05) and hunger, desire to eat as well as energy intake at lunch were significantly lower (P < 0.05).

CONCLUSIONS

Whole grain rye crisp bread caused lower self-reported hunger, higher fullness and less desire to eat compared to refined wheat bread. It also led to a lower energy intake after an ad libitum lunch. Results were stronger and/or more consistent when the test meal portion was smaller and accounted for a larger proportion of the total energy intake of the breakfast.