In vitro digestibility of starch and protein in cooked wheat and oat whole flours: A comparative study

Whole grains have garnered significant attention in the food industry due to their retained abundant nutrients when compared to refined grains. However, limited knowledge exists regarding the digestive behavior of starch and protein. This study compared the physicochemical properties and in vitro starch and protein digestibility of cooked whole wheat flour (WF) and naked oat flour (NOF), and evaluated the impact of endogenous components (protein, lipid, β-glucan, and polyphenol) on the physicochemical properties and digestibility of WF and NOF. The result indicated that the final hydrolysis rate of WF samples (starch: 23.2 %∼46.3 %; protein: 23.1 %∼63.0 %) was lower than that of NOF samples (starch: 32.1 %∼61.0 %; protein: 32.3 %∼63.6 %). The removal of different endogenous components led to improved digestibility of starch and protein in both WF and NOF. This study contributes to the understanding of the starch and protein digestibility of whole grains, consequently facilitating the development of whole grain products.

Aligning front-of-pack labelling with dietary guidelines: including whole grains in the health star rating

PURPOSE

Front-of-pack labelling systems, such as the Health Star Rating (HSR), aim to aid healthy consumer dietary choices and complement national dietary guidelines. Dietary guidelines aim to be holistic by extending beyond the individual nutrients of food, including other food components that indicate diet quality, including whole grains. We aimed to test the feasibility of including whole grains in the HSR algorithm, to better inform dietary guidance in Australia coherent with existing dietary guidelines.

METHODS

We assigned whole-grain points as a favourable component of the HSR based on the whole-grain content of foods. We compared the original, and three modified HSR algorithms (including altered thresholds for star ratings) using independent-samples median tests. Finally, we used Spearman's correlation to measure the strength of association between an item's nutritional composition (all components of the HSR algorithm including all favourable and unfavourable components) and their HSR using each algorithm.

RESULTS

Up to 10 points were added for products with ≥ 50% whole-grain content, with no points for products with < 25%. Adjusting the HSR score cut-off by 3 points for grain products created the greatest difference in median HSR between refined and whole-grain items (up to 2 stars difference), compared to the original algorithm (a maximum of 1 star).

CONCLUSIONS

The addition of whole grains to the HSR algorithm improved the differentiation of refined and whole-grain items, and therefore better aligned with dietary guidelines. Holistic approaches to food guidance systems are required to provide consistent messaging and inform positive food choices.

Assessment of dietary intake and its inflammatory potential in persons with pediatric-onset multiple sclerosis

OBJECTIVE

To compare diet and the modified dietary inflammatory index (mDII) between individuals with pediatric-onset multiple sclerosis (PoMS), monophasic acquired demyelinating syndromes (monoADS), and controls.

METHODS

The association between diet, mDII, and disease status was examined in 131 individuals with PoMS/monoADS/controls (38/45/48) using logistic regression.

RESULTS

The associations between diet and PoMS were modest, reaching significance for whole grain intake (adjusted odds ratio, aOR=0.964, 95 % confidence intervals, CI:0.934-0.995) but not mDII (aOR=1.20, 95 %CI:0.995-1.46) versus controls. No findings for monoADS reached significance versus controls.

CONCLUSIONS

Individuals with PoMS, but not monoADS, had lower dietary whole grain intake than controls.

Modulation of starch structure, swallowability and digestibility of 3D-printed diabetic-friendly food for the elderly by dry heating

Elderly people often experience difficulty in swallowing and have impaired regulation of the nervous system. Furthermore, their blood glucose level can rise easily after eating. Therefore, functional foods that are easy to swallow and can maintain blood glucose at a lower level have been an important research topic in recent years. In this study, 3D printing was combined with dry heating to modify the starch in white quinoa and brown rice to develop whole grain foods with Osmanthus flavor that meet the dietary habits of the elderly. The samples were tested for printability, swallowing performance, and in vitro digestion. The results showed that after dry heating, all samples had shear-thinning properties and could pass through the extrusion nozzle of the printer smoothly. Both white quinoa and brown rice showed improved printability and self-support compared to the control. B45 (white quinoa, dry heating for 45 min) and C45 (brown rice, dry heating for 45 min) had significant elasticity and greater internal interaction strength during swallowing to resist disintegration of food particles during chewing. B45, C30, and C45, conformed to class 4 consistency and were characterized by easy swallowing of the diet. Further, dry heating resulted in greater resistance to enzymatic degradation of white quinoa and brown rice starch, with overall in vitro digestibility lower than the control.

Adherence to the nordic diet is associated with anxiety, stress, and depression in recovered COVID-19 patients, a case-control study

BACKGROUND

Follow-up of COVID-19 recovered patients to discover important adverse effects on other organs is required. The psychological health of COVID-19 patients may be affected after recovery.

AIM

We aimed to evaluate the association between adherence to the Nordic diet (ND) and psychological symptoms caused by COVID-19 after recovery.

METHOD

Dietary data on 246 qualified adults (123 cases and 123 controls). The dietary intake in this case-control study was calculated by a reliable and valid food frequency questionnaire (FFQ). Depression Anxiety Stress Scale (DASS), Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and Short-Form Health Survey (SF-36) were used to analyze participant's anxiety, stress, depression, sleep quality, insomnia, and quality of life of participants.

RESULTS

There was a significant inverse relationship between total anxiety, stress, and depression scores and the intake of whole grains (P < 0.05). Furthermore, there was a significant inverse association between depression and fruit intake (P < 0.05). A significant negative correlation was found between insomnia and sleep quality and the intake of root vegetables (P < 0.05). In the multinomial-regression model, a significant association between the Nordic diet and anxiety, stress, and depression was found only in the case group (OR = 0.719, 95% CI 0.563-0.918, p-value = 0.008; OR = 0.755, 95% CI 0.609-0.934, P-value = 0.010, and, OR = 0.759, 95% CI 0.602-0.956, P-value = 0.019 respectively).

CONCLUSION

Adherence to the Nordic diet might reduce anxiety, stress, and depression in recovered COVID-19 patients.

Increasing fibre intake in the UK: lessons from the Danish Whole Grain Partnership

Diets deficient in fibre are reported globally. The associated health risks of insufficient dietary fibre are sufficiently grave to necessitate large-scale interventions to increase population intake levels. The Danish Whole Grain Partnership (DWP) is a public-private enterprise model that successfully augmented whole-grain intake in the Danish population. The potential transferability of the DWP model to Slovenia, Romania and Bosnia-Herzegovina has recently been explored. Here, we outline the feasibility of adopting the approach in the UK. Drawing on the collaborative experience of DWP partners, academics from the Healthy Soil, Healthy Food, Healthy People (H3) project and food industry representatives (Food and Drink Federation), this article examines the transferability of the DWP approach to increase whole grain and/or fibre intake in the UK. Specific consideration is given to the UK's political, regulatory and socio-economic context. We note key political, regulatory, social and cultural challenges to transferring the success of DWP to the UK, highlighting the particular challenge of increasing fibre consumption among low socio-economic status groups - which were also most resistant to interventions in Denmark. Wholesale transfer of the DWP model to the UK is considered unlikely given the absence of the key 'success factors' present in Denmark. However, the DWP provides a template against which a UK-centric approach can be developed. In the absence of a clear regulatory context for whole grain in the UK, fibre should be prioritised and public-private partnerships supported to increase the availability and acceptability of fibre-rich foods.

Partial substitution of red meat or processed meat with plant-based foods and the risk of colorectal cancer

OBJECTIVES

Shifting from animal-based to plant-based diets could reduce colorectal cancer (CRC) incidence. Currently, the impacts of these dietary shifts on CRC risk are ill-defined. Therefore, we examined partial substitutions of red or processed meat with whole grains, vegetables, fruits or a combination of these in relation to CRC risk in Finnish adults.

METHODS

We pooled five Finnish cohorts, resulting in 43 788 participants aged ≥ 25 years (79% men). Diet was assessed by validated food frequency questionnaires at study enrolment. We modelled partial substitutions of red (100 g/week) or processed meat (50 g/week) with corresponding amounts of plant-based foods. Cohort-specific hazard ratios (HR) for CRC were calculated using Cox proportional hazards models and pooled together using random-effects models. Adjustments included age, sex, energy intake and other relevant confounders.

RESULTS

During the median follow-up of 28.8 years, 1124 CRCs were diagnosed. We observed small risk reductions when red meat was substituted with vegetables (HR 0.97, 95% CI 0.95 - 0.99), fruits (0.97, 0.94 - 0.99), or whole grains, vegetables and fruits combined (0.97, 0.95 - 0.99). For processed meat, these substitutions yielded 1% risk reductions. Substituting red or processed meat with whole grains was associated with a decreased CRC risk only in participants with < median whole grain intake (0.92, 0.86 - 0.98; 0.96, 0.93 - 0.99, respectively; pinteraction=0.001).

CONCLUSIONS

Even small, easily implemented substitutions of red or processed meat with whole grains, vegetables or fruits could lower CRC risk in a population with high meat consumption. These findings broaden our insight into dietary modifications that could foster CRC primary prevention.

Potential impact of time trend of whole grain intake on burden of major cancers in China

Numerous studies have revealed associations between high intake of whole grains and reduced risk of various cancers. Yet, in recent decades, the traditional Chinese diets have been challenged by reduction in whole grains and increase in refined grains. To assess the impact of this dietary transition on cancer prevention, we analyzed the time trend of whole grain intake using nationally representative sampling data of over 15 thousand individuals from the China Health and Nutrition Survey. We applied the comparative risk assessment method to estimate the population attributable fraction of cancers due to insufficient whole grain intake from 1997 to 2011 and projected the trend of whole grain intake and the associated burden of cancers to 2035. We found a significant decrease of approximately 59% of whole grain intake in the Chinese population from 1997 to 2011. Compared with 1997, insufficient intake of whole grains was responsible for 9940 more cases of breast cancer, 12,903 more cases of colorectal cancer and 434 more cases of pancreatic cancer in 2011. Our projections suggest that if every Chinese would consume 125 g whole grain per day as recommended by the latest Chinese Dietary Guidelines, 0.63% bladder cancer, 8.98% breast cancer, 15.85% colorectal cancer, 3.86% esophageal cancer, 2.52% liver cancer and 2.22% pancreatic cancer (totaling 186,659 incident cases) could theoretically be averted by 2035. Even if everyone maintained the 2011 whole grain intake level, an estimated 8.38% of cancer events could still be prevented by 2035.

Fifty shades of grain - Increasing whole grain consumption through daily messages

Despite numerous health benefits, the majority of consumers, in particular young adults, show low levels of whole grain consumption behaviour (WGCB). In order to increase WGCB, this pre-registered experimental study investigates the effect of a two weeks message intervention. Participants (n = 329) received either information about health benefits, recipe suggestions, a combination of both, or about a control topic. We evaluated WGCB at three time points: prior to, immediately after (post), and one month after the intervention (follow-up). Our findings show that participants read the message on most of the days and on average, evaluate the health-only message most positively. Furthermore, we found that health messages, but not recipe suggestions significantly increase WGCB at the follow-up measure. This effect was serially mediated by attitudes and behavioural intentions at the post-intervention measure, with more positive attitudes and higher intentions leading to more WGCB. Although health messages are an effective tool to influence WGCB, the effect is small in magnitude and consumption levels remain rather low. We discuss implications for future research and for the communication of whole grain related health benefits among different stakeholders in the health sector.

Effect of cereal bran phenolic profile on Maillard reaction products formation during hydrothermal treatment

Maillard reaction products (MRP) contribute to sensory quality of various foods. Whole grains (WG) are rich in phenols which may influence Maillard reaction pathways during thermal processing and impact WG product sensory attributes. This study investigated how WG phenolic profile affects MRP formation. Amylase-hydrolyzed wheat (white and red) and sorghum (white, red, tannin) brans were hydrothermally processed at 150 °C/6 min, and characterized for MRP using colorimetry, fluorescence spectroscopy, HPLC-MS/MS, and HS-SPME/GC-MS. Bran phenolic structure, and to a lesser extent content, had larger influence on MRP formation than protein/amino acid profile. Polymeric tannins (both in situ and when added to wheat brans) strongly inhibited volatile and non-volatile MRP intermediates and melanoidin formation, likely via their carbocation depolymerization intermediates trapping furans. Principle component analysis demonstrated clear segregation of volatiles formation based on bran phenolic profile. Phenolic composition should be considered in WG product formulation and processing to achieve desired MRP formation.

Cereal intake and mortality in older Chinese: a 15-year follow-up of a prospective cohort study

PURPOSE

We examined the association between whole grain and refined grain intake with all-cause, cancer and cardiovascular disease (CVD) mortality using the data from the Guangzhou Biobank Cohort Study.

METHODS

19,597 participants aged 50+ years were recruited from 2003 to 2006 and followed-up until April 2021. Multivariable Cox regression was used to calculate hazard radios (HRs) and 95% confidence intervals (CIs). Substitution analysis was used to replace a serving (50 g/day) of whole grain with a serving of refined grain.

RESULTS

During 286,821 person-years of follow-up, 4385 deaths occurred, including 1450 from cancer, 1678 from CVD and 1257 from other causes. Compared with never whole grain intake, the highest intake category of whole grain (> 300 g/week) was associated with lower risk of all-cause (HR 0.90, 95% CI 0.82-0.98) and CVD mortality (HR 0.85, 0.74-0.98). Compared with the low-intake category of refined grain (< 500 g/day), the highest intake category (> 900 g/week) was associated with a lower risk of cancer mortality (HR 0.76, 0.62-0.95), but a higher risk of CVD mortality (HR 1.25, 1.03-1.51). No significant associations were found between whole grain intake and cancer mortality nor refined grain and all-cause mortality. The HRs of all-cause, cancer and CVD mortality substituting a serving of whole grain for refined grain were 0.96 (0.94-0.99), 1.01 (0.99-1.02) and 0.95 (0.90-0.99), respectively.

CONCLUSION

We have first shown that in older Chinese, whole grain intake was associated with lower risk of all-cause and CVD mortality. Our results suggest that intake of whole grain of at least 300 g/week and refined grain of ≤ 900 g/day might be suitable for older Asian. Substituting 50 g/day of whole grain for refined grain was associated with a 4-5% lower risk of all-cause and CVD mortality.

Measures of carbohydrate quality and their association with diet quality and cardiometabolic health outcomes in Singapore middle-aged and older adults

BACKGROUND AND AIMS

Carbohydrate quality may play a key role in cardiometabolic health and disease risk. This study aimed to assess the dietary carbohydrate quality of the free-living middle-aged and older adults in Singapore, and its association with overall diet quality and cardiometabolic health.

METHODS AND RESULTS

This cross-sectional study examined the diet and cardiometabolic disease risk indicators of middle-aged and older adults in Singapore (n = 104). Dietary carbohydrate quality was assessed as the pass and fail rate of the population to four measures of carbohydrate quality: (i) dietary fiber recommended daily allowance (RDA), (ii) whole-grain recommendation, (iii) free sugar recommendation, and (iv) carbohydrate metrics. The association between each carbohydrate quality measure and diet quality, as well as cardiometabolic health, was assessed. Except for free sugar recommendation, the carbohydrate quality of the population was found to be poor with a low adherence (20-36%) to three measures. Subjects meeting these measures had generally higher intakes of fiber, protein, and most micronutrients compared with subjects who failed. Meeting different variants of the carbohydrate metrics was associated with 60% lower odds of pre-hypertensive blood pressure (p = 0.037; p = 0.047), and meeting the dietary fiber RDA was associated with lower waist circumference (p = 0.021).

CONCLUSION

An improvement in carbohydrate quality is warranted among free-living middle-aged and older adults in Singapore. Not all measures of carbohydrate quality were equally effective in preserving overall diet quality; the carbohydrate metrics and dietary fiber RDA can be identified as effective measures in relation to cardiometabolic disease risk.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ CLINICAL TRIAL REGISTRATION: NCT03554954, 13 Sept. 2018.

The relation of whole grain surrogate estimates and food definition to total whole grain intake in the Finnish adult population

OBJECTIVES

Challenges in estimating total whole grain intake have led to the use of surrogate estimates, of which accuracy has not been assessed. We examined the suitability of five potential surrogates (dietary fiber; bread; rye bread; rye, oat and barley combined; rye) and a whole grain food definition to measure total whole grain intake in the Finnish adult population.

METHODS

Our data comprised 5094 Finnish adults participating in the national FinHealth 2017 Study. Dietary intake was assessed by a validated FFQ. Food and nutrient intakes, including total whole grain, were calculated utilizing the Finnish Food Composition Database. The Healthgrain Forum whole grain food definition was applied to examine definition-based whole grain intake. Spearman correlations and quintile cross-classifications were calculated.

RESULTS

Definition-based whole grain intake and consumption of rye, oat and barley combined had consistently the strongest correspondence with total whole grain intake. Rye and rye bread consumption also corresponded well with total whole grain intake. The correspondences of dietary fiber and bread with total whole grain were lower and more affected by the exclusion of energy under-reporters. Furthermore, their correlations with total whole grain intake varied the most between population subgroups.

CONCLUSIONS

Rye-based estimates, especially rye, oat and barley combined, and definition-based whole grain intake appeared suitable surrogate estimates of total whole grain intake for epidemiological research of Finnish adults. The variation between surrogate estimates in their correspondence with total whole grain intake demonstrated the need for further evaluation of their accuracy in different populations and regarding specific health outcomes.

Plant-Based Diets and Cancer Prognosis: a Review of Recent Research

PURPOSE OF REVIEW

Although plant-based diets are recommended for cancer prevention, their role in cancer survival is still uncertain. The purpose of this systematic review is to summarize the association between postdiagnosis plant-based diets and prognosis in cancer survivors.

RECENT FINDINGS

There is indication that higher intake of plant-based foods was associated with improved prognosis in cancer survivors. For colorectal cancer survival, a better prognosis was observed for a high intake of whole grains and fibre. For breast cancer survival, a higher intake of fruit, vegetable and fibre and a moderate intake of soy/isoflavone were associated with beneficial outcomes. A higher vegetable fat intake was related to improved prognosis in prostate cancer survivors. Emerging evidence suggests benefits of postdiagnosis plant-based diets on prognosis in cancer survivors. However, given the high heterogeneity between studies, further research in cancer survivors, considering clinical factors (e.g. treatment, stage) and methodological aspects (e.g. timing of dietary assessment), is needed.

Influence of barley inclusion method and protease supplementation on growth performance, nutrient utilisation, and gastrointestinal tract development in broiler starters

The influence of the method of barley inclusion (fine, coarse and whole barley) in a wheat-based diet and protease supplementation (0 and 0.20 g/kg) on growth performance, nutrient utilisation and gastrointestinal tract development of broilers (d 1 to 21) was evaluated in a 3 × 2 factorial arrangement. Whole barley (WB) grains were ground in a hammer mill to pass through the screen sizes of 2.5 and 8.0 mm to achieve fine (FB) and coarse (CB) barley particle sizes, respectively. A total of 288, one-day-old male broilers were allotted to 36 cages (6 cages/treatment; 8 birds/cage). There was no significant (P > 0.05) interaction between barley inclusion method and protease for any growth performance or nutrient utilisation parameters. Birds fed diets containing CB and WB showed higher (P < 0.05) weight gain, and digestibility of dry matter, nitrogen, calcium, gross energy, and ileal digestible energy compared to those fed FB diets. Compared to the birds fed FB diets, feed per gain was lower (P < 0.05) in birds fed diets made of WB. Fat digestibility of the birds fed CB was higher (P < 0.05) than those fed FB and WB birds. Compared to FB and CB diets, inclusion of WB resulted in heavier (P < 0.05) gizzards but reduced (P < 0.05) gizzard pH. Supplemental protease, however, had no effects (P > 0.05) on growth performance and nutrient utilisation, most likely due to the well balanced digestible amino acids and high inherent digestibility of protein in the basal diet, and/or the presence of exogenous carbohydrase and phytase. In conclusion, the present results showed that the inclusion of coarsely ground and whole barley in a wheat-based diet can enhance nutrient and energy utilisation and is beneficial to the growth performance of young broilers.

Cost-effective options for increasing consumption of under-consumed food groups and nutrients in the USA

OBJECTIVE

To identify the most cost-effective options/contributors of under-consumed food groups and nutrients in the USA.

DESIGN

Twenty-four-hour dietary recall data were used for the dietary sources of under-consumed food groups and nutrients. Costs were estimated using USDA National Food Price Database 2001-2004 after adjustments for inflation using Consumer Price Index.

SETTING

National Health and Nutrition Examination Survey, 2013-2016.

PARTICIPANTS

A total of 10 112 adults aged 19+ years.

RESULTS

Top five cost-effective options for food groups were apple and citrus juice, bananas, apples, and melons for fruit; baked/boiled white potatoes, mixtures of mashed potatoes, lettuce, carrots and string beans for vegetables; oatmeal, popcorn, rice, yeast breads and pasta/noodles/cooked grains for whole grain; and reduced-fat, low-fat milk, flavoured milk and cheese for dairy. Top five cost-effective sources of under-consumed nutrients were rice, tortillas, pasta/noodles/cooked grains, rolls and buns, and peanut butter-jelly sandwiches for Mg; grits/cooked cereals, low- and high-sugar ready-to-eat (RTE) cereal, rolls and buns, and rice for Fe; low- and high-sugar RTE cereals, rice, protein and nutritional powders, and rolls and buns for Zn; carrots, margarine, other red and orange vegetables, liver and organ meats, butter and animal fats for vitamin A; and citrus juice, other fruit juice, vegetable juice, mustard and other condiments, and apple juice for vitamin C.

CONCLUSIONS

Apple/citrus juice, white potatoes/carrots, oatmeal, RTE cereals and milk were the most cost-effective food sources of multiple under-consumed food groups and nutrients and can help promote healthy eating habits at minimal cost.

In vitro digestion of eight types of wholegrains and their dietary recommendations for different populations

Wholegrains have been promoted for human consumption due to their various health benefits. However, different wholegrains vary in nutritional composition and their beneficial impact on health. In this study, we compared the in vitro starch and protein digestibility, as well as dietary fiber content of eight different wholegrains including barley, buckwheat, coix seed, foxtail millet, oat, proso millet, quinoa, and sorghum and their porridges. We found that boiling improved starch digestibility of all grains, and protein digestibility except proso millet and sorghum. Porridges made from oats, quinoa, or buckwheat are considered healthier than others due to their lower glycemic index and glycemic load, higher digestible protein content and amino acid bioaccessibility, and higher dietary fiber content (>12%). This study could provide a comprehensive nutritional composition and digestibility of the eight types of wholegrains and their porridges. Dietary recommendations were also given for different populations based on factor analysis.

Defining whole-grain foods - does it change estimations of intakes and associations with CVD risk factors: an Australian and Swedish perspective

Historically, there are inconsistencies in the calculation of whole-grain intake, particularly through use of highly variable whole-grain food definitions. The current study aimed to determine the impact of using a whole-grain food definition on whole-grain intake estimation in Australian and Swedish national cohorts and investigate impacts on apparent associations with CVD risk factors. This utilised the Australian National Nutrition and Physical Activity Survey 2011-2012, the Swedish Riksmaten adults 2010-2011 and relevant food composition databases. Whole-grain intakes and associations with CVD risk factors were determined based on consumption of foods complying with the Healthgrain definition (≥30 % whole grain (dry weight), more whole than refined grain and meeting accepted standards for 'healthy foods' based on local regulations) and compared with absolute whole-grain intake. Compliance of whole-grain containing foods with the Healthgrain definition was low in both Sweden (twenty-nine of 155 foods) and Australia (214 of 609 foods). Significant mean differences of up to 24·6 g/10 MJ per d of whole-grain intake were highlighted using Swedish data. Despite these large differences, application of a whole-grain food definition altered very few associations with CVD risk factors, specifically, changes with body weight and blood glucose associations in Australian adults where a whole-grain food definition was applied, and some anthropometric measures in Swedish data where a high percentage of whole-grain content was included. Use of whole-grain food definitions appears to have limited impact on measuring whole-grain health benefits but may have greater relevance in public health messaging.

Aligning nutrient profiling with dietary guidelines: modifying the Nutri-Score algorithm to include whole grains

Purpose

Whole grains, generally recognised as healthy choices, are not included in most nutrient profiling systems. We tested modifications to the Nutri-Score algorithm to determine whether including whole grains would provide an improved measure of food, and overall diet quality.

Methods

The whole-grain content of food, with a minimum cut-point of 25%, was added to the algorithm, following similar methods used to score other health-promoting components such as fibre. We applied and compared the original and the modified Nutri-Score to food composition and dietary intake data from Australia, France, the United Kingdom, and the United States.

Results

At the food level, correlations between whole-grain content and food nutritional score were strengthened using the modified algorithm in Australian data, but less so for the other countries. Improvements were greater in grain-specific food groups. The largest shift in Nutri-Score class was from B to A (best score). At the dietary intake level, whole-diet nutritional scores for individuals were calculated and compared against population-specific diet-quality scores. With modifications, correlations with diet-quality scores were improved slightly, suggesting that the modified score better aligns with national dietary guidelines. An inverse linear relationship between whole-diet nutritional score and whole-grain intake was evident, particularly with modifications (lower whole-diet nutritional score indicative of better diet quality).

Conclusion

Including a whole-grain component in the Nutri-Score algorithm is justified to align with dietary guidelines and better reflect whole grain as a contributor to improved dietary quality. Further research is required to test alternative algorithms and potentially other nutrient profiling systems.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02718-6.

Estimated economic burden of cancer associated with suboptimal diet in the United States

PURPOSE

Suboptimal diet is a preventable cause of cancer. We aimed to estimate the economic burden of diet-associated cancer among US adults.

METHODS

We used a Comparative Risk Assessment model to quantify the number of new cancer cases attributable to seven dietary factors among US adults ages 20 + years. A Markov cohort model estimated the 5-year medical costs for 15 diet-associated cancers diagnosed in 2015. We obtained dietary intake from 2013 to 2016 National Health and Nutrition Examination Survey, cancer incidence, and survival from 2008 to 2014 Surveillance, Epidemiology, and End Results (SEER) program, and medical costs from 2007 to 2013 linked SEER-Medicare data.

RESULTS

The estimated 5-year medical costs of new diet-associated cancer cases diagnosed in 2015 were $7.44 (2018 US$). Colorectal cancer had the largest diet-related 5-year medical costs of $5.32B. Suboptimal consumption of whole grains ($2.76B), dairy ($1.82B), and high consumption of processed meats ($1.5B) accounted for the highest medical costs. Per-person medical costs attributable to suboptimal diet vary by gender, race, and age group.

CONCLUSIONS

Suboptimal diet contributes substantially to the economic burden of diet-associated cancers among US adults. This study highlights the need to implement population-based strategies to improve diet and reduce cancer burden in the US.

Total and whole grain intake in Latin America: findings from the multicenter cross-sectional Latin American Study of Health and Nutrition (ELANS)

PURPOSE

Understanding whole-grain intake and its associated factors is essential to tackle the double burden of malnutrition faced by Latin American countries. This study aimed to characterize total and whole grain intake in Latin American countries and to investigate foods contributing to these intake in the region.

METHODS

Data were obtained from the multicenter cross-sectional survey Latin American Study of Nutrition and Health (ELANS), including 9128 participants residing in urban areas of eight Latin American countries. Data collection was performed via two household visits using a standardized questionnaire and two 24 h dietary recalls. Usual dietary intake of total grain foods and foods containing whole grains was estimated. The association between the intake of grain food groups and sociodemographic variables was investigated using multiple linear regression models with random intercepts.

RESULTS

Mean intake of total grain foods and foods containing whole grains was 318.6 g/d and 14.7 g/d, respectively. Total grain foods were less consumed by participants at older ages (-9.8 g/d), and females (-9.9 g/d), and more consumed by those in the lowest socioeconomic category (24.8 g/d). Foods containing whole grains were more consumed by participants at older ages (3.3 g/d), and females (4.0 g/d), while those in the lowest socioeconomic category consumed 2.9 g/d less. Major contributors to energy provided from foods containing whole grains were oatmeal, masa harina, whole-wheat bread, corn chips, and wheat crackers.

CONCLUSION

The intake of grain foods represented a substantial part of the Latin American population's diet, but the intake of foods containing whole grains was extremely low in all assessed countries.

Milling fractions composition of common (Fagopyrum esculentum Moench) and Tartary (Fagopyrum tataricum (L.) Gaertn.) buckwheat

Buckwheat is a pseudocereal with important nutritional qualities and great potential for broad consumption. The study aimed to determine the biochemical composition, antioxidant properties and multi-mineral composition of the whole grains, hulls, bran, and the light flour of common (Fagopyrum esculentum Moench) and Tartary (Fagopyrum tataricum (L.) Gaertn.) buckwheat harvested in two consecutive years. Significant differences between fractions of both species were observed. On the other hand, the differences between the production years were not so significant. Biochemical and multi-mineral compositions of common and Tartary buckwheat were comparable, while significant differences between species were observed in antioxidant properties. The antioxidant potential (AOP), total phenolic content (TPC), and total flavonoid content (TFC) were higher in all fractions of Tartary buckwheat compared to individual fractions of common buckwheat. Fourteen minerals were quantified in fractions. Contents of all major minerals and most of the trace minerals were the highest in bran fraction.

Gelatinisation and milling whole-wheat increases postprandial blood glucose: randomised crossover study of adults with type 2 diabetes

AIMS/HYPOTHESES

We examined the effects of milling and cooking whole grains in water to achieve starch gelatinisation on postprandial blood glucose using a randomised crossover open-label design. Participants were adults with type 2 diabetes whose body weight or medications had not changed in at least 3 months.

METHODS

Postprandial blood glucose (measured as incremental AUC [iAUC]) was measured following consumption of four nutrient-matched whole-wheat porridge test-meals. Test-meals included gelatinised or native starch and were made with either finely milled or intact whole-wheat.

RESULTS

Eighteen adults (63.1 ± 9.8 years, HbA_1c 57.0 ± 11.5 mmol/mol [7.4 ± 3.2%]) completed the study. iAUC was higher following cooked meals (gelatinised starch) than following uncooked meals (native starch) (mean difference [MD] 268, 95% CI 188, 348 mmol/l × min). Consuming finely milled whole-wheat produced a higher iAUC compared with intact whole-wheat (MD 173, 95% CI 80, 266 mmol/l × min). There was no evidence of an interaction effect (p = 0.841).

CONCLUSIONS

Both the nature of starch and the grain structure of whole-wheat influence the glycaemic response of adults with type 2 diabetes mellitus.

FUNDING

Baking Industry Research Trust of New Zealand and the Riddet Centre of Research Excellence.

TRIAL REGISTRATION

www.anzctr.org.au ACTRN12617000328370.

Carbohydrates: Separating fact from fiction

The role of carbohydrate in a healthy diet has been controversial. The confusion over carbohydrate has come from the long standing limitation of dietary recall studies as well as inability in many of these studies to delineate between the different types of carbohydrates. It is the aim of this paper, to understand and review the data on the role of carbohydrate as pertaining to weight, insulin resistance, diabetes, inflammation, lipids, as well as epidemiological data on long-term cardiovascular outcome and all-cause mortality. We have reviewed the latest epidemiological and intervention studies on fiber, whole grain, and refined carbohydrates on weight, diabetes, lipids as well as major adverse cardiac events that we deemed were scientifically rigorous. High intakes of dietary fiber and whole grains are associated with positive effects on metabolic health while diet high in sugar and refined carbohydrates have negative effects on cardiometabolic health. Consistent evidence indicates that low fat and low carbohydrate diets at comparable energy levels have similar effects on body weight. Large epidemiological studies show when carbohydrates are substituted for animal-derived fat or protein mortality increased while carbohydrate exchanged with plant based protein was associated with mortality reduction. Types of carbohydrate appear to be critical for mortality and cardiovascular events. Evidence shows that quality of the carbohydrate determine cardiometabolic health and cardiovascular events. Given that most people worldwide currently consume less than 20 g of dietary fiber per day with persistently high consumption of refined carbohydrates, current evidence emphasize the need for additional measures to increase the amount and the diversity of fiber intake for improvement of cardiometabolic and cardiovascular outcomes.

Health benefits of whole grain: effects on dietary carbohydrate quality, the gut microbiome, and consequences of processing

Grains are important sources of carbohydrates in global dietary patterns. The majority of these carbohydrates, especially in refined-grain products, are digestible. Most carbohydrate digestion takes place in the small intestine where monosaccharides (predominantly glucose) are absorbed, delivering energy to the body. However, a considerable part of the carbohydrates, especially in whole grains, is indigestible dietary fibers. These impact gut motility and transit and are useful substrates for the gut microbiota affecting its composition and quality. For the most part, the profile of digestible and indigestible carbohydrates and their complexity determine the nutritional quality of carbohydrates. Whole grains are more complex than refined grains and are promoted as part of a healthy and sustainable diet mainly because the contribution of indigestible carbohydrates, and their co-passenger nutrients, is significantly higher. Higher consumption of whole grain is recommended because it is associated with lower incidence of, and mortality from, CVD, type 2 diabetes, and some cancers. This may be due in part to effects on the gut microbiota. Although processing of cereals during milling and food manufacturing is necessary to make them edible, it also offers the opportunity to still further improve the nutritional quality of whole-grain flours and foods made from them. Changing the composition and availability of grain carbohydrates and phytochemicals during processing may positively affect the gut microbiota and improve health.

Whole grain intake favorably affects blood glucose and serum triacylglycerols in overweight and obese children: A randomized controlled crossover clinical trial

OBJECTIVES

The aim of this study was to determine the effects of whole grain consumption on the metabolic profiles of overweight or obese children.

METHODS

This was a randomized crossover clinical trial with 44 overweight or obese girls. After a 2-wk run-in period, girls were randomly assigned to either intervention or control groups. Participants in the intervention group were asked to obtain 50% of their grain servings from whole grain foods each day for 6 wk. Those in the control group were asked not to consume any of these foods. A 4-wk washout period was applied following which participants were crossed over to the alternate arm. Fasting blood samples were taken before and after each phase of study.

RESULTS

Mean (± SD) age and body mass index was 11.2 ± 1.49 y and 23.5 ± 2.5 kg/m², respectively. Mean whole grain intake in intervention and control groups throughout the study was 26.5 and 3.7 g/d, respectively (P = 0.01). Whole grain consumption resulted in lower concentrations of plasma glucose (changes from baseline in intervention group: -0.10 versus 0.21 mmol/L in control group, P = 0.01), serum triacylglycerols (changes from baseline in intervention group: -0.18 versus 0.08 mmol/L in control group, P = 0.01) and higher concentrations of serum high-density lipoprotein cholesterol (changes from baseline in intervention group: 0.16 versus -0.14 mmol/L in control group, P = 0.05) after 6 wk of intervention. No effects of whole grain intake on serum concentrations of total- and low-density lipoprotein cholesterol or on blood pressure were found.

CONCLUSION

This study provided evidence supporting the beneficial effects of whole grain foods on serum concentrations of glucose, triacylglycerols and high-density lipoprotein cholesterol in overweight children.

Knowledge, attitudes and practices related to WG consumption among college students: a cross-sectional study in Chongqing, China

OBJECTIVES

This work aimed to investigate WG (WG)-related knowledge, attitudes, practices (KAPs) and factors affecting WG consumption among college students in Chongqing, China.

STUDY DESIGN

A cross-sectional study was performed among 2500 students from six universities using a self-administered questionnaire.

METHODS

The chi-squared test and binary logistic regression were used for data analysis.

RESULTS

Only 14.7% of the participants were aware of WG, 57.1% supported the consumption of WG, and only 8.5% consumed WG regularly in the last month. Participants with poor knowledge of WG were about 2 times more likely to not concern about chronic diseases (CDs) than concern about CDs (odds ratio [OR] = 2.241, 95% confidence interval [CI], 1.030-4.877). Women were less likely to have a poor attitude to WG compared with men (OR = 0.682, 95% CI, 0.529-0.878), whereas women were more likely to have a poor WG practice (OR = 2.335, 95% CI, 1.327-4.111).

CONCLUSIONS

Although results showed low levels of WG knowledge and practices, this study still supports positive attitudes to acquire WG-related knowledge among college students in Chongqing, China.

Effects of dietary whole grain, fruit, and vegetables on weight and inflammatory biomarkers in overweight and obese women

PURPOSE

The separate effects of whole grain (WG) and fruit and vegetable (F&V) diets on inflammatory biomarkers have not been assessed. Therefore, we evaluated these two high-fiber diets in relation to inflammation indices in obese and overweight women.

STUDY DESIGN

Parallel randomized clinical trial.

METHODS

In the present study, 75 women were recruited and randomly assigned to three diet groups: a whole grain diet (WG-D) group, F&V group, and a combined whole grain and F&V diet group (WGFV-D) for 10 weeks. As a "feeding trial" all participants were asked to visit the clinic daily and eat prescribed foods in the presence of a nutritionist. Anthropometric indices and biochemical biomarkers were measured at baseline and after 10 weeks of the trial.

RESULTS

Each of the three diet groups showed significant changes in serum biomarkers (CRP, TNF-α, IL-6, D-dimer, and serum fibrinogen) after following the diet for 10 weeks (P = 0.01). In adjusted models, significant changes were observed for CRP, TNF-α, IL-6, D-dimer, and serum fibrinogen (P = 0.01). In a model adjusted for malondialdehyde (MDA) level, a trend toward significance was observed (P = 0.05). Consumption of all three different diets for 10 weeks showed statistically significant change for all biomarkers (P < 0.05) the most notable changes in inflammatory indices were observed among participants following the WG diet.

CONCLUSIONS

Study results indicate that consumption of high-fiber diets, especially the WG diet, can help lower inflammatory levels and prevent subsequent adverse health consequences.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

Development, validity and reproducibility of a whole grain food frequency questionnaire in Malaysian children

Background

To date, there is no validated whole grain assessment tool for children in any Southeast Asian countries. Hence, there is a need for a valid tool to assess whole grain intake among Malaysian children. This study aimed to develop, validate and test the reproducibility of a food frequency questionnaire (FFQ) in estimating whole grain intake among Malaysian children.

Methods

A total of 392 children participated in the FFQ development and 112 children aged 9–12 years participated in the validation phase; with a subsample of 50 children participating in the reproducibility phase. Three-day diet record (3DR) as the reference method in validation phase. Spearman correlations, mean difference, Bland-Altman plot and cross-classification analyses were used to assess validity. The reproducibility was tested through a repeat administration of the FFQ, with 1 month time interval. Reproducibility analyses involved intra-class correlation coefficient (ICC), Cronbach’s alpha and cross-classification analyses.

Results

The FFQ consisted of 156 whole grain food items from six food groups. Mean intake of whole grain in FFQ1 and 3DR were correlated well (r = 0.732), demonstrated good acceptance of the FFQ. Bland Altman plots showed relatively good agreement for both the dietary methods. Cross-classification of whole grain intake between the two methods showed that < 9.9% of children were grossly misclassified. Outcomes from ICC (0.989) and Cronbach’s alpha (0.995) demonstrated excellent reliability. All the children were classified in the same or adjacent quartile of whole grain intake.

Conclusions

Overall, the findings support the validity of the developed FFQ to appropriately estimate the whole grain intake in Malaysian children. This validated FFQ will be a valuable tool for future studies, to analyses the impact of whole grain consumption with disease relationship among Malaysian schoolchildren.

Intake of whole grain and associations with lifestyle and demographics: a cross-sectional study based on the Danish Diet, Cancer and Health-Next Generations cohort

PURPOSE

The aim was to analyze the intake of whole grain (WG) and associations with lifestyle and demographics in a newly established cohort of Danish adults.

METHODS

Between 2015 and 2019, Danes were enrolled into The Diet, Cancer and Health-Next Generations cohort. A total of 38,553 persons were included in the current cross-sectional study, where all completed a 376-item food frequency questionnaire, a lifestyle questionnaire, and a physical examination in a study center where physical measurements and biological samples were collected.

RESULTS

The median intake of WG was 79 g/10 mega joule (MJ) and 54% of the participants consumed the amount of WG recommended in Denmark, which is 75 g/10 MJ. The probability of consuming the recommended amount of WG was highest among men, persons < 30 years, students, persons with body mass index (BMI) < 25 kg/m², persons participating in sports, who did not exceed the recommended maximum intake of alcohol and did not smoke. The probability of having a low intake of WG defined as < 25 g/10 MJ was highest among persons with short education, BMI ≥ 25 kg/m², persons not participating in sports, persons having an alcohol intake above the recommended maximum level and persons being active smokers.

CONCLUSION

The median intake of WG was 79 g/10 MJ. The probability of consuming at least 75 g WG/10 MJ was highest among persons who also adhered to healthy lifestyle measured by other factors. Only 6% of the cohort participants consumed < 25 g WG/10 MJ, these persons were more likely to have a general less healthy lifestyle.

The relevance of whole grain food definitions in estimation of whole grain intake: a secondary analysis of the National Nutrition and Physical Activity Survey 2011-2012

OBJECTIVE

To determine the impacts of using a whole grain food definition on measurement of whole grain intake compared with calculation of total grams of intake irrespective of the source.

DESIGN

The Australian whole grain database was expanded to identify foods that comply with the Healthgrain whole grain food definition (≥30 % whole grains on a dry weight basis, whole grain ingredients exceeds refined grain and meeting accepted standards for healthy foods based on local regulations). Secondary analysis of the National Nutrition and Physical Activity Survey (NNPAS) 2011-2012 dietary intake data included calculation of whole grain intakes based on intake from foods complying with the Healthgrain definition. These were compared with intake values where grams of whole grain in any food had been included.

SETTING

Australia.

PARTICIPANTS

Australians (≥2 years) who participated in the NNPAS 2011-2012 (n 12 153).

RESULTS

Following expansion of the whole grain database, 214 of the 609 foods containing any amount of whole grain were compliant with the Healthgrain definition. Significant mean differences (all P < 0·05) of 2·84-6·25 g/d of whole grain intake (5·91-9·44 g/d energy adjusted) were found when applying the Healthgrain definition in comparison with values from foods containing any whole grain across all age groups.

CONCLUSIONS

Application of a whole grain food definition has substantial impact on calculations of population whole grain intakes. While use of such definitions may prove beneficial in settings such as whole grain promotion, the underestimation of total intake may impact on identification of any associations between whole grain intake and health outcomes.

Whole grain and cereal fibre intake in the Australian Health Survey: associations to CVD risk factors

OBJECTIVE

To explore associations of whole grain and cereal fibre intake to CVD risk factors in Australian adults.

DESIGN

Cross-sectional analysis. Intakes of whole grain and cereal fibre were examined in association to BMI, waist circumference (WC), blood pressure (BP), serum lipid concentrations, C-reactive protein, systolic BP, fasting glucose and HbA1c.

SETTING

Australian Health Survey 2011-2013.

PARTICIPANTS

A population-representative sample of 7665 participants over 18 years old.

RESULTS

Highest whole grain consumers (T3) had lower BMI (T0 26·8 kg/m2, T3 26·0 kg/m2, P < 0·0001) and WC (T0 92·2 cm, T3 90·0 cm, P = 0·0005) compared with non-consumers (T0), although only WC remained significant after adjusting for dietary and lifestyle factors, including cereal fibre intake (P = 0·03). Whole grain intake was marginally inversely associated with fasting glucose (P = 0·048) and HbA1c (P = 0·03) after adjusting for dietary and lifestyle factors, including cereal fibre intake. Cereal fibre intake was inversely associated with BMI (P < 0·0001) and WC (P < 0·0008) and tended to be inversely associated with total cholesterol, LDL-cholesterol and apo-B concentrations, although associations were attenuated after further adjusting for BMI and lipid-lowering medication use.

CONCLUSIONS

The extent to which cereal fibre is responsible for the CVD-protective associations of whole grains may vary depending on the mediators involved. Longer-term intervention studies directly comparing whole grain and non-whole grain diets of similar cereal fibre contents (such as through the use of bran or added-fibre refined grain products) are needed to confirm independent effects.

New insights into potential nutritional effects of dietary saponins in protecting against the development of obesity

Excessive energy intake, poor physical exercise and genetics/epigenetics are instrumental for the development of obesity. Because of rapidly emerging evidences related to off-target effects and toxicity of anti-obesity drugs, there is a need to search for more effective and targeted drugs for treatment of obesity. Substantial studies have found the nutritional effects of dietary saponins (bio-detergents) in terms of decreasing the synthesis of lipids, suppressing adipogenesis, inhibiting intestinal absorption of lipids, and promoting fecal excretion of bile acids and triglycerides. Dietary saponin have been approved as potent pancreatic lipase inhibitors, disaccharidase enzyme inhibitors, antagonistic to in vitro lipogenesis and in vivo appetite suppressants, antioxidants, immune-regulators, prevent fatty liver formation, protects epithelial vasculature and regulate body weight. Many dietary saponins, such as sibutramine, morgoside, sessiloside, soysaponin B, and diosgenin, have treatment potential against the development of obesity. Excellent scientific achievements have been developed for a better understanding the mechanism of saponins in preventing obesity.

Weight loss induced by whole grain-rich diet is through a gut microbiota-independent mechanism

The prevalence of overweight and obesity has increased worldwide. Obesity is a well-known risk factor of type 2 diabetes mellitus and cardiovascular disease and raises public health concerns. Many dietary guidelines encourage the replacement of refined grains with whole grains (WGs) to enhance body weight management. Current evidence regarding interrelationships among WGs, body weight, and gut microbiota is limited and inconclusive. In this editorial, we comment on the article by Roager et al published in the recent issue of the Gut 2019; 68(1): 83-93. In the study, obese patients (25 < body mass index < 35 kg/m²) were randomly assigned to receive two 8-wk dietary controlling periods with WGs and refined grain-rich diet. The results showed significantly decreased body weight in the WG group. Either the composition of gut microbiota or short-chain fatty acids, the leading end product of fermentation of non-digestible carbohydrate by gut microbiota, did not differ between the two groups. The study highly indicated that a WG-rich diet reduced body weight independent of gut microbiota. We then raised some plausible mechanisms of how WGs might influence body weight and demonstrated more literature in line with WGs enhance body weight control through a microbiota-independent pathway. Possible mechanisms include: (1) The abundant dietary fiber contents of WGs increase satiety, satiation, energy excretion from stool, and energy expenditure simultaneously decreasing energy absorption and fat storage; (2) The plentiful amount of polyphenols of WGs improve energy expenditure by hampering adipocyte maturation and function; (3) The sufficient magnesium and zinc of WGs guarantee lean body mass growth and decrease fat mass; (4) The effect of WGs on brown adipose tissue is a key component of non-shivering thermogenesis; and (5) The increase of adiponectin by WGs enhances glucose utilization, lipid oxidation, and energy expenditure.

Whole grain and high-fibre grain foods: How do knowledge, perceptions and attitudes affect food choice?

The health benefits of whole grains and dietary fibre are well established, however intakes of both remain low across the globe. Innovative added-fibre refined grain products may present a solution to increase fibre intakes given potential sensory barriers to whole grain intake. However, to consider the efficacy of such products, or potential alternative measures, an awareness of consumer knowledge, perceptions and attitudes towards both whole grain and added-fibre grain foods is needed. Focus groups (with adults with no formal nutrition education) were conducted to explore factors affecting consumer grain choice. Discussions were transcribed verbatim and analysed using inductive thematic analysis. Nine focus groups composed of 52 participants (23 men; 29 women) were conducted. Participants tended to report choosing 'grainy' bread but few other whole grain foods. Most participants were unaware of the long-term health benefits of whole grains, recommended whole grain intakes, or how to identify foods that were high in whole grains, thereby limiting motivation to increase intake. Additionally, scepticism surrounding the health value of carbohydrate-based foods appeared to hinder grain intakes in general. These findings suggest that further public education and promotion of whole grain benefits, with a focus on food-based targets and messaging, may be important in efforts to increase whole grain and subsequently fibre intakes. Added-fibre grain products may be a useful addition, specifically for avid whole grain-avoiders who are unlikely to accept whole grain sensory properties. However, as most participants were open to whole grain consumption, industry innovation should also focus efforts on increasing availability and variety of products high in whole grains.

Whole grain consumption and human health: an umbrella review of observational studies

Whole grains have been associated with a number of health benefits. We systematically reviewed existing meta-analyses of observational studies and evaluated the level of evidence for their putative effects based on pre-selected criteria. Of the 23 included studies, we found convincing evidence of an inverse association between whole grain consumption and risk of type-2 diabetes and colorectal cancer; possible evidence of decreased risk of colon cancer and cardiovascular mortality with increased whole grain intake, as well as increased risk of prostate cancer. Limited or insufficient evidence was available for all other outcomes investigated. Overall findings are encouraging for a positive effect of whole grain consumption on certain diseases, especially highly prevalent metabolic diseases, however, uncertainty of some negative associations deserves further attention.

Whole Grains, Dietary Fibers and the Human Gut Microbiota: A Systematic Review of Existing Literature

BACKGROUND

The health benefits of dietary fibers have been proved for a long time. The importance of microbiota has been identified in human health and there is a growing interest to study the factors affecting it.

OBJECTIVE

This systematic review aimed to investigate the impact of fiber and whole grains (WGs) on human gut microbiota in a patent-based review.

METHODS

All related clinical trials were systematically searched on PubMed and Scopus search engines from inception up to Feb 2020. Interventional human studies reporting changes in microbiota by using any type of grains/fibers were included. The following information was extracted: date of the publication, location and design of the study, sample size, study population, demographic characteristics, the amount of dietary WGs/fiber, the duration of intervention, the types of grains or fibers, and changes in the composition of the microbiota.

RESULTS

Of 138 studies which were verified, 35 studies with an overall population of 1080 participants, met the inclusion criteria and entered the systematic review. The results of interventional trials included in this review suggest some beneficial effects of consuming different amounts and types of WGs and fibers on the composition of intestinal microbiota. Most included studies showed that the intake of WGs and fibers increases bifidobacteria and lactobacilli and reduces the pathogenic bacteria, such as Escherichia coli and clostridia in the human gut.

CONCLUSION

The consumption of WGs/fibers may modify the intestinal microbiota and promote the growth of bifidobacteria and lactobacilli. Nevertheless, further research is warranted in different populations and pathological conditions.

Application of the ≤ 10:1 carbohydrate to fiber ratio to identify healthy grain foods and its association with cardiometabolic risk factors

PURPOSE

Optimal metrics to assess healthfulness of carbohydrate-rich products are not well established. We investigated how the content per 10 g of carbohydrate of at least 1 g of fiber (≤ 10:1-ratio) related to nutritional quality in grain foods as well as cardiometabolic risk factors in São Paulo, Brazil.

METHODS

Data were from the cross-sectional population-based study 2015 Health Survey of São Paulo, including a probabilistic sample of urban residents in the city. Participants (n = 1188) aged 20 + years completed a 24-h dietary recall and a subsample of 603 participants had blood samples, anthropometrics, and blood pressure measurements collected, and answered a second 24-h recall. Energy and nutrient contents of grain foods meeting or not meeting the ≤ 10:1-ratio were evaluated using linear regression models. The association between consumption (percent energy, %E) of grain foods meeting the ≤ 10:1-ratio and cardiometabolic risk factors were investigated using linear regression models.

RESULTS

Foods meeting the ≤ 10:1-ratio had less available carbohydrate (- 3.0 g/serving), total sugar (- 7.4 g/serving), added sugar (- 7.2 g/serving) and saturated fat (- 0.7 g/serving), and more dietary fiber (+ 3.5 g/serving), protein (+ 2.1 g/serving), potassium (+ 100.1 mg/serving), iron (+ 0.9 mg/serving), selenium (+ 4.2 µg/serving), magnesium (+ 38.7 mg/serving), and zinc (+ 1.1 mg/serving). Each increase in 1%E consumption of grain foods meeting the ≤ 10:1-ratio was associated with lower levels of blood triacylglycerol (- 10.7%), the triacylglycerol/high-density lipoprotein cholesterol ratio (- 14.9%), fasting insulin (- 13.6%), and homeostasis model assessment for insulin resistance (- 14.0%).

CONCLUSION

The ≤ 10:1-ratio identified grain foods with higher nutritional quality and higher intakes of these foods were associated with cardiometabolic risk factors related to atherogenic dyslipidemia and insulin resistance.

Biomarkers of cereal food intake

Background/objectives

Cereal foods are major contributors to the daily energy, protein, and dietary fiber intake all over the world. The role of cereals in human health is dependent on whether they are consumed as refined or whole grain and on cereal species. To unravel the underlying mechanisms of health effects attributed to specific cereal foods and to provide more precise dietary advice, there is a need for improved dietary assessment of whole-grain intake. Dietary biomarkers of specific cereals, different fractions or cereal-containing foods could offer such a possibility. The aim of this review was to summarize the current status on biomarkers of different cereals, fractions, and specific cereal foods.

Subjects and methods

A literature review was conducted and putative biomarkers of different cereals and pseudo-cereals (wheat, oats, rye, barley, rice, and quinoa) as well as for different grain fractions (whole grain, refined grain, bran) and foods were summarized and discussed.

Results

Several putative biomarkers have been suggested for different cereals, due to their unique presence in these grains. Among the biomarkers, odd-numbered alkylresorcinols are the most well-studied and -evaluated biomarkers and reflect whole-grain wheat and rye intake. Even-numbered alkylresorcinols have been suggested to reflect quinoa intake. Recent studies have also highlighted the potential of avenanthramides and avenacosides as specific biomarkers of oat intake, and a set of biomarkers have been suggested to reflect rice bran intake. However, there are yet no specific biomarkers of refined grains. Most biomarker candidates remain to be evaluated in controlled interventions and free-living populations before applied as biomarkers of intake in food and health studies.

Conclusion

Several putative biomarkers of different cereals have been suggested and should be validated in human studies using recently developed food intake biomarker validation criteria.

Contribution of gut microbiota to metabolism of dietary glycine betaine in mice and in vitro colonic fermentation

BACKGROUND

Accumulating evidence is supporting the protective effect of whole grains against several chronic diseases. Simultaneously, our knowledge is increasing on the impact of gut microbiota on our health and on how diet can modify the composition of our bacterial cohabitants. Herein, we studied C57BL/6 J mice fed with diets enriched with rye bran and wheat aleurone, conventional and germ-free C57BL/6NTac mice on a basal diet, and the colonic fermentation of rye bran in an in vitro model of the human gastrointestinal system. We performed 16S rRNA gene sequencing and metabolomics on the study samples to determine the effect of bran-enriched diets on the gut microbial composition and the potential contribution of microbiota to the metabolism of a novel group of betainized compounds.

RESULTS

The bran-enriched study diets elevated the levels of betainized compounds in the colon contents of C57BL/6 J mice. The composition of microbiota changed, and the bran-enriched diets induced an increase in the relative abundance of several bacterial taxa, including Akkermansia, Bifidobacterium, Coriobacteriaceae, Lactobacillus, Parasutterella, and Ruminococcus, many of which are associated with improved health status or the metabolism of plant-based molecules. The levels of betainized compounds in the gut tissues of germ-free mice were significantly lower compared to conventional mice. In the in vitro model of the human gut, the production of betainized compounds was observed throughout the incubation, while the levels of glycine betaine decreased. In cereal samples, only low levels or trace amounts of other betaines than glycine betaine were observed.

CONCLUSIONS

Our findings provide evidence that the bacterial taxa increased in relative abundance by the bran-based diet are also involved in the metabolism of glycine betaine into other betainized compounds, adding another potential compound group acting as a mediator of the synergistic metabolic effect of diet and colonic microbiota.

Consumption of whole grain food and its determinants in a general Italian population: Results from the INHES study

BACKGROUND AND AIMS

Whole grain (WG) food consumption is associated with lower risk of cardiovascular disease, cancer and neurological diseases. The aim of this study was to assess the consumption of WG food and its major demographic, socioeconomic, psychosocial and behavioral determinants in a general Italian population.

METHODS AND RESULTS

Data were from the Italian Nutrition & Health Survey (INHES), a telephone-based survey established in 2010-2013 including 9422 participants aged ≥5 years from all over Italy. WG food intake was assessed by the European Food Propensity Questionnaire and included bread, pasta, breakfast cereals, biscuits and WG soups. WG consumption was categorized as none, occasional (<1 time/week) and regular (≥1 time/week). Overall, 26.9% of the sample reported a regular consumption of WG food (27.2% of adults aged 20-97 y, and 21.9% of children/adolescents aged 5-19 y). In both age-groups, the major food source contributing to total WG intake was WG bread followed by WG pasta. Among adults, greater consumption of WG was associated with healthier lifestyle (e.g. sport activity), and higher educational level. Eating meals outside of the house in adults, and spending >2 h/day watching TV in children/adolescents were inversely associated with WG intake.

CONCLUSIONS

The percentage of WG consumers in Italy in 2010-2013 appears to be quite low and still below that recorded in other countries of Europe where consumption is frequently over 50 percent. WG consumption is likely to be influenced by socioeconomic status and is associated with a number of psychosocial factors, meal patterns and eating-related behaviors.

A higher ratio of refined grain to whole grain is associated with a greater likelihood of chronic kidney disease: a population-based study

A growing number of studies suggest that diet and renal function are related. However, little is known about the link between both whole grain (WG) and refined grain (RG) consumption and kidney function parameters. Thus, we investigated the association of WG and RG with urinary albumin to creatinine ratio (ACR) and prevalent chronic kidney disease (CKD). Data from participants of the National Health and Nutrition Examination Surveys (NHANES) from 2005 to 2010 were collected. Estimated glomerular filtration rate (eGFR) was calculated by the CKD Epidemiology Collaboration equation. Survey design and sample weights were taken into consideration for statistical analyses. Finally, we included 16 325 participants from NHANES, 6·9 % of whom had prevalent CKD. In models adjusted for age, sex, race, fasting blood glucose, blood pressure, adiposity, hypertension and diabetes status, mean eGFR significantly increased across increasing quartiles of WG (Q1: 88·2 v. Q4: 95·4 ml/min per 1·73 m2, P&lt;0·001), whereas it significantly decreased across increasing quartiles of RG (Q1: 97·2 v. Q4: 88·4 ml/min per 1·73 m2, P&lt;0·001). Furthermore, serum uric acid levels and ACR significantly decreased across quartiles of WG (both P&lt;0·001). In multivariable-adjusted logistic regression models, the likelihood of prevalent CKD was 21 % lower in the highest WG quartile compared with the lowest one. In conclusion, our results shed light on the beneficial impact of WG on kidney function and CKD, whereas RG is adversely associated with eGFR.

Comparative effects of different whole grains and brans on blood lipid: a network meta-analysis

Purpose

The comparative effects of different whole grains and brans on blood lipid are still not totally elucidated. We aimed to estimate and rank the effects of different whole grains and brans on the control of blood lipid.

Methods

We performed a strategic literature search of PubMed, EMBASE and the Cochrane Library for relevant trials. Both pairwise meta-analyses and network meta-analyses were conducted to compare and rank the intervention strategies of whole grains and brans for the control of total cholesterol (TC), LDL cholesterol (LDL-C), HDL cholesterol (HDL-C), and triglycerides (TG).

Results

Fifty-five eligible trials with a total of 3900 participants were included. Cumulative ranking analyses showed that oat bran was the most effective intervention strategy for TC and LDL-C improvements, with significant decreases of − 0.35 mmol/L (95% CI − 0.47, − 0.23 mmol/L) and − 0.32 mmol/L (95% CI − 0.44, − 0.19 mmol/L) in TC and LDL-C compared with control, respectively. In comparison with control, oat was associated with significant reductions in TC by − 0.26 mmol/L (95% CI − 0.36, − 0.15 mmol/L) and LDL-C by − 0.17 mmol/L (95% CI − 0.28, − 0.07 mmol/L), which was ranked as the second best treatment. Barley, brown rice, wheat and wheat bran were shown to be ineffective in improving blood lipid compared with control.

Conclusions

This network meta-analysis suggests that oat bran and oat are ranked higher than any other treatments for the regulations of TC and LDL-C, indicating that increasing oat sources of whole grain may be recommended for lipid control.

Electronic supplementary material

The online version of this article (10.1007/s00394-018-1827-6) contains supplementary material, which is available to authorized users.

Association between whole grain intake and breast cancer risk: a systematic review and meta-analysis of observational studies

Background

Epidemiological studies have found that high whole grain intake may be associated with a reduced risk of breast cancer. However, the evidence has not been consistent. We conducted a meta-analysis to quantitatively assess the association between whole grain intake and breast cancer risk.

Methods

Relevant observational studies were identified by searching PubMed, Embase, Cochrane library databases, and Google Scholar through April 2017. Summary relative risk (RR) estimates were calculated using random-effects meta-analysis.

Results

A total of 11 studies, including 4 cohort and 7 case-control studies and involving 131,151 participants and 11,589 breast cancer cases, were included in the current meta-analysis. The pooled RR of breast cancer for those with high versus low whole grain intake was 0.84 (95% confidence interval [CI]: 0.74 to 0.96, p = 0.009; I² = 63.8%, p_{for heterogeneity} = 0.002). Subgroup analysis by study design found a significant inverse association in the case-control studies (RR: 0.69; 95% CI: 0.56 to 0.87, p = 0.001; I² = 58.2%, p _{for heterogeneity} = 0.026), but not in the cohort studies (RR, 0.96; 95% CI: 0.82 to 1.14, p = 0.69; I² = 66.7%, p for heterogeneity = 0.029). In addition, stratified analysis suggested that sample size could be a potential source of heterogeneity.

Conclusions

Results of the current meta-analysis suggest that high intake of whole grains might be inversely associated with a reduced risk of breast cancer, and the inverse association was only observed in case-control but not cohort studies. More large-scale cohort studies are needed to confirm the inverse association observed.

Electronic supplementary material

The online version of this article (10.1186/s12937-018-0394-2) contains supplementary material, which is available to authorized users.

Adiposity mediates the association between whole grain consumption, glucose homeostasis and insulin resistance: findings from the US NHANES

Background

Growing evidence suggests an inverse association between whole grain (WG) consumption and insulin resistance (IR) or inflammation. However, it is still unclear whether adiposity plays a role in this relationship.

We investigated whether the associations between WG intake with IR, glucose homeostasis and inflammation are mediated by adiposity in US adults.

Methods

The 2005–2010 National Health and Nutrition Examination Surveys participants were included. WG intake was assessed and markers of IR and glucose homeostasis, inflammation, general and central adiposity. Analysis of co-variance and mediation analysis were applied, while accounting for survey design.

Results

Overall 16,621 participants were included in this analysis (mean age = 47.1 years, 48.3% men). After adjustment for age, gender, and race, mean C-reactive protein (CRP), apolipoprotein B (apo-B), fasting blood glucose (FBG), insulin, homeostatic model assessment of IR (HOMA-IR) and β cell function (HOMA-β), hemoglobin A_1c (HbA_1c), and 2 h glucose after an oral glucose tolerance test decreased with increasing quarters of WG (all p < 0.001). Body mass index (BMI) had significant mediation effects on the associations between WG intake and CRP, apo-B, fasting glucose, insulin, HOMA-IR, HOMA-B, HbA_1c, triglyceride to high density lipoprotein-cholesterol (TG:HDL-C) ratio and triglyceride-glucose (TyG) index (all p < 0.05) after adjustment for age, gender, race/ethnicity, educational status, smoking and level of physical activity. Both waist circumference (WC) and anthropometrically predicted visceral adipose tissue (apVAT) mediated the association between WG intakes with CRP, FBG, HbA_1c, TG:HDL-C ratio and TyG index, i.e. WC and apVAT had indirect effect (all p < 0.05).

Conclusion

Our findings provide insights into the favourable impact of WG consumption on IR and inflammation, which may be affected by both central and visceral adiposity, i.e. the link between WG with IR and inflammation is more mediated in overweight/obese compared with lean individuals.

Subjective feelings of appetite of wholegrain breakfasts evaluated under controlled, laboratory and 'at home' conditions

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.

Evaluation of alkylresorcinols in adipose tissue biopsies as a long-term biomarker of whole-grain wheat and rye intake in free-living Swedish men and women

OBJECTIVE

Wheat and rye, the most consumed whole grains (WG) in the Nordic countries, contain alkylresorcinols (AR) in their bran. AR concentrations in human adipose tissue might reflect long-term WG rye and wheat intake. We aimed to evaluate AR concentrations in adipose tissue biopsies as a long-term biomarker of WG wheat and rye intake in free-living Swedish men and women.

DESIGN

Cross-sectional study. AR concentrations in adipose tissue biopsies were analysed and compared with long-term WG intake assessed by three FFQ (repeated over a period of 14 years in men, 17 years in women) and with plasma AR concentrations.

SETTING

The Cohort of Swedish Men between 1997 and 2010 and the Swedish Mammography Cohort between 1987 and 2003, Sweden.

SUBJECTS

Men (n 149) and women (n 109).

RESULTS

Long-term WG rye intake estimated with repeated FFQ correlated (r=0·31-0·41, P<0·01) with adipose-tissue AR concentrations, while WG wheat intake correlated only weakly (r=0·17-0·33, P<0·05). Total AR concentration in adipose tissue was 61 % lower in women than in men at similar energy-adjusted WG wheat and rye intakes, but plasma concentrations were similar. AR concentrations in adipose tissue correlated well with plasma concentrations (r=0·49-0·81, P<0·001).

CONCLUSIONS

AR in adipose tissue reflected long-term WG rye but not WG wheat intake, probably due to poor precision in estimating WG wheat intake by FFQ. AR in adipose tissue appears promising as a biomarker of long-term WG rye intake but should be adjusted for sex.

Consumers' health-related perceptions of bread - Implications for labeling and health communication

There is a wide variety of commercial bread types and the present study identifies potential pitfalls in consumer evaluations of bread from a health perspective. The aim is to describe consumers' health-related perceptions of bread by exploring which health-related quality attributes consumers associate with bread and whether there are differences with regard to age, gender and education level. A postal and web-based sequential mixed-mode survey (n = 1134, 62% responded online and 38% by paper) with open-ended questions and an elicitation task with pictures of commercial breads were used. Responses were content analyzed and inductively categorized. Three fourths (n = 844) knew of breads they considered healthy; these were most commonly described using terms such as "coarse," "whole grain," "fiber rich," "sourdough," "crisp," "less sugar," "dark," "rye," "seeds," "a commercial brand," "homemade" and "kernels." The breads were perceived as healthy mainly because they "contain fiber," are "good for the stomach," have good "satiation" and beneficial "glycemic properties." The frequency of several elicited attributes and health effects differed as a function of age group (18-44 vs. 45-80 years), gender and education level group (up to secondary education vs. university). Difficulties identifying healthy bread were perceived as a barrier for consumption especially among consumers with a lower education level. Several of the health effects important to consumers cannot be communicated on food packages and consumers must therefore use their own cues to identify these properties. This may lead to consumers being misled especially if a bread is labeled e.g., as a sourdough bread or a rye bread, despite a low content.

Higher intake of fish and fat is associated with lower plasma s-adenosylhomocysteine: a cross-sectional study

Several B-vitamins act as co-factors in one-carbon metabolism, a pathway that plays a central role in several chronic diseases. However, there is a lack of knowledge of how diet affects markers in one-carbon metabolism. The aim of this study was to explore dietary patterns and components associated with one-carbon metabolites. We hypothesized that intake of whole-grains and fish would be associated with lower Hcy, and higher SAM:SAH ratio due to their nutrient content. We assessed dietary information using a four-day dietary record in 118 men and women with features of the metabolic syndrome. In addition we assessed whole-blood fatty acid composition and plasma alkylresorcinols. Plasma s-adenosylmethionine (SAM), s-adenosylhomocysteine (SAH), homocysteine (Hcy) and vitamin B₁₂ was included as one-carbon metabolism markers. We used principal component analysis (PCA) to explore dietary patterns and multiple linear regression models to examine associations between dietary factors and one-carbon metabolites. PCA separated subjects based on prudent and unhealthy dietary patterns, but the dietary pattern score was not related to the one-carbon metabolites. Whole grain intake was found to be inversely associated to plasma Hcy (-4.7% (-9.3; 0.0), P=.05) and total grain intake tended to be positively associated with SAM and SAH (2.4% (-0.5; 5.5), P=.08; 5.8% (-0.2; 12.1), P=.06, respectively, per SD increase in cereal intake). Fish intake was inversely associated with plasma Hcy and SAH concentrations (-5.4% (-9.7; -0.8), P=.02 and -7.0% (-12.1; -1.5), P=.01, respectively) and positively associated with the SAM:SAH ratio (6.2% (1.6; 11.0), P=.008). In conclusion, intake and fish and whole-grain appear to be associated with a beneficial one-carbon metabolism profile. This indicates that dietary components could play a role in regulation of one-carbon metabolism with a potential impact on disease prevention.

Antioxidant activity of whole grain highland hull-less barley and its effect on liver protein expression profiles in rats fed with high-fat diets

PURPOSE

Whole grain exhibits potential for regulating lipid levels, possibly because of its antioxidant activity. This study aims to investigate the antioxidant activity of whole grain highland hull-less barley (WHLB) and its effect on liver protein expression profiles in rats fed with high-fat diets.

METHODS

Antioxidant activity of WHLB was investigated in vitro by analyzing phenolic and pentosan contents and oxygen radical absorbance capacity (ORAC). Proteins involved in lipid regulation were investigated in vivo by analyzing liver protein expression profiles in Sprague-Dawley rats fed with high-fat diet (HFD) with or without WHLB.

RESULTS

WHLB possessed high total phenolic content (259.90 mg/100 g), total pentosan content (10.74 g/100 g), and ORAC values (418.05 ± 5.65 μmol/g). Rats fed with WHLB diet exhibited significantly (P < 0.05) lower liver lipid levels than those fed with the control HFD diet. Seven differentially expressed proteins were detected through liver proteome analysis and were found to be correlated with 11 pathways, including lipid metabolism, through annotation with Kyoto Encyclopedia of Genes and Genomes. Quantitative real-time polymerase chain reaction analysis showed that rats given with WHLB diet exhibited down-regulated expression of heat shock protein 60 (HSP60) and phosphatidylethanolamine binding protein 1 (PEBP1) and up-regulated expression of enoyl-coenzyme A hydratase (ECH) and peroxiredoxin 6 (PRDX6).

CONCLUSIONS

HSP60, PEBP1, ECH, and PRDX6 may be involved in the lipid regulatory effect of WHLB. Moreover, the regulation of PRDX6 may be related to the antioxidant activity of WHLB.