Whole-grain intake is associated with reduced risk of non-communicable diseases (NCDs). Greater understanding of major food sources of whole grains globally, and how intake has been quantified, is essential to informing accurate strategies aiming to increase consumption and reduce NCD risk. Therefore, the aim of this review was to identify the primary food sources of whole-grain intake globally and explore how they are quantified and reported within literature, and their recommendation within respective national dietary guidelines. A structured scoping review of published articles and grey literature used a predefined search strategy across electronic databases. Data was extracted and summarised based on identified outcomes (e.g., primary sources of whole-grain intake, quantification methods). Dietary intake values were noted where available. Thirteen records across 24 countries identified bread and bread rolls, and ready-to-eat cereals as primary sources of whole-grain intake in Australia, New Zealand, Europe, the United Kingdom, and Northern America. Elsewhere, sources vary and for large parts of the world (for example Africa and Asia), intake data is limited or non-existent. Quantification of whole grain also varied across countries, with some applying different whole-grain food definitions, resulting in a whole-grain intake based on only consumption of select “whole-grain” foods. National dietary guidelines were consistent in promoting whole grain intake and providing examples of country specific whole-grain foods. Consistency in whole-grain calculation methods is needed to support accurate and comparative research informing current intake evidence and promotional efforts. National dietary guidelines are consistent in promoting whole-grain intake, however there is variability in recommendations.

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.

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.

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<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<0·001). Furthermore, serum uric acid levels and ACR significantly decreased across quartiles of WG (both P<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.

Colonic effects of extruded whole-grain sorghum diets were evaluated using a model of growing rats. In all, twenty-four male Wistar rats were fed control (C), extruded white sorghum (EWS) or red sorghum (ERS). Consumption of sorghum diets showed satiety properties, with reduction of caecal pH, and lower activity of β-glucosidase and β-glucuronidase enzymes. Decreased copper zinc superoxide dismutase and manganese superoxide dismutase and increased catalase and glutathione peroxidase levels were observed in colonic mucosa. The induction of antioxidant enzymes occurred through the activation of the nuclear factor erythroid 2-related factor 2 protein and its subsequent translocation into the nucleus. ERS was able to decrease the proliferation of proximal mucosa of colon, demonstrating a possible effect against colorectal tumourigenesis. EWS increased proliferation and also apoptosis, ensuring the re-establishment of homoeostasis of the colonic mucosa. No antioxidant systemic effect (serum or hepatic level) was observed. It is likely that despite the extrusion the low bioavailability of the phenolic compounds of sorghum diets caused them to exert mainly acute effects at the colon level. Extruded whole-grain sorghum is a good functional ingredient that might be promising in dietary prevention of intestinal diseases.

Currently whole grain is incorporated into poultry diets to lower production costs, stimulate the development of the gizzard, prevent potentially pathogenic bacteria from entering the intestine and improve the growth rate and feed conversion of birds. The present review discusses the results of experiments performed on turkeys where whole grain (WG) or large-sized feed particles were incorporated into diets with the use of different processing methods (with pre- or post-pelleting inclusion) and in different quantities. The results of recent experiments indicated that, within the first month, gizzard weight increased significantly when the size of feed particles was increased from 380 to 806 mm, or when turkey diets were supplemented with 20% WG. In older birds, gizzard weight increased when the WG content of pelleted diets exceeded 20%. Dietary dilution with WG did not cause significant changes in the development or functionality of the small intestine, including mucosal enzyme activity. The presence of WG in the diet increased the amount of coarse particles in the digesta leaving the gizzard, which did not lower the apparent digestibility of dry matter and crude fibre or nitrogen retention. The inclusion of WG in turkey diets led to a decrease in the counts of Clostridium spp., Campylobacter and/or Escherichia coli, and an increase in the counts of Lactobacillus spp. and/or Bifidobacterium spp. in the caecal digesta. However the effect of WG inclusion in turkey diets on gut morphology has been investigated in only a few studies to date, and the results are inconclusive.

This review article discusses the production results of experiments performed on turkeys, where WG, mainly whole wheat (WW), was incorporated into diets with the use of different methods: i) pre-pelleting inclusion of WG, ii) post-pelleting inclusion of WG with dilution of the daily diet, iii) post-pelleting inclusion of whole grain without dilution of the daily diet and iv) free-choice feeding. The latest experiments conducted between 2012 and 2013 on turkeys fed WW indicated that: (1) pre-pelleting inclusion of 20% WW had no effect on the body weight (BW) of turkeys or feed conversion ratio (FCR), (2) moderate (up to 20% on average) dilution of standard turkey diets with WW had no effect on the final BW of birds or muscle yield, and improved feed utilisation, in particular when WW was fed instead of ground or pelleted grain, (3) post-pelleting inclusion of WG in diets supplemented with protein-mineral-vitamin concentrate allowed to increase the amount of WW up to 25 and 30% in the daily ration in feeding periods of 4-8 and 9-12 weeks, respectively. However, in free-choice feeding, WW can result in poorer growth performance of turkeys due to an inadequate total protein intake.

Increased whole-grain (WG) consumption reduces the risk of CVD, type 2 diabetes and some cancers, is related to reduced body weight and weight gain and is related to improved intestinal health. Definitions of ‘WG’ and ‘WG food’ are proposed and used in some countries but are not consistent. Many countries promote WG consumption, but the emphasis given and the messages used vary. We surveyed dietary recommendations of fifty-three countries for mentions of WG to assess the extent, rationale and diversity in emphasis and wording of any recommendations. If present, recommendations were classified as either ‘primary’, where the recommendation was specific for WG, or ‘secondary’, where recommendations were made in order to achieve another (primary) target, most often dietary fibre intake. In total, 127 organisations were screened, including government, non-governmental organisations, charities and professional bodies, the WHO and European Food Safety Authority, of which forty-nine including WHO provide a WG intake recommendation. Recommendations ranged from ‘specific’ with specified target amounts (e.g. x g WG/d), ‘semi-quantitative’ where intake was linked to intake of cereal/carbohydrate foods with proportions of WG suggested (e.g. x servings of cereals of which y servings should be WG) to ‘non-specific’ based on ‘eating more’ WG or ‘choosing WG where possible’. This lack of a harmonised message may result in confusion for the consumer, lessen the impact of public health messages and pose barriers to trade in the food industry. A science-based consensus or expert opinion on WG recommendations is needed, with a global reach to guide public health decision making and increase WG consumption globally.

Cereal-based foods are key components of the diet and they dominate most food-based dietary recommendations in order to achieve targets for intake of carbohydrate, protein and dietary fibre. Processing (milling) of grains to produce refined grain products removes key nutrients and phytochemicals from the flour and although in some countries nutrients may be replaced with mandatory fortification, overall this refinement reduces their potential nutritional quality. There is increasing evidence from both observational and intervention studies that increased intake of less-refined, whole-grain (WG) foods has positive health benefits. The highest WG consumers are consistently shown to have lower risk of developing CVD, type 2 diabetes and some cancers. WG consumers may also have better digestive health and are likely to have lower BMI and gain less weight over time. The bulk of the evidence for the benefits of WG comes from observational studies, but evidence of benefit in intervention studies and potential mechanisms of action is increasing. Overall this evidence supports the promotion of WG foods over refined grain foods in the diet, but this would require adoption of standard definitions of ‘whole grain’ and ‘whole-grain foods’ which will enable innovation by food manufacturers, provide clarity for the consumer and encourage the implementation of food-based dietary recommendations and public health strategies.

Increased whole grain intake has been shown to reduce the risk of many non-communicable diseases. Countries including the USA, Canada, Denmark and Australia have specific dietary guidelines on whole grain intake but others, including the UK, do not. Data from 1986/87 and 2000/01 have shown that whole grain intake is low and declining in British adults. The aim of the present study was to describe whole grain intakes in the most current dietary assessment of UK households using data from the National Diet and Nutrition Survey rolling programme 2008–11. In the present study, 4 d diet diaries were completed by 3073 individuals between 2008 and 2011, along with details of socio-economic status (SES). The median daily whole grain intake, calculated for each individual on a dry weight basis, was 20 g/d for adults and 13 g/d for children/teenagers. The corresponding energy-adjusted whole grain intake was 27 g/10 MJ per d for adults and 20 g/10 MJ per d for children/teenagers. Whole grain intake (absolute and energy-adjusted) increased with age, but was lowest in teenagers (13–17 years) and younger adults up to the age of 34 years. Of the total study population, 18 % of adults and 15 % of children/teenagers did not consume any whole-grain foods. Individuals from lower SES groups had a significantly lower whole grain intake than those from more advantaged classifications. The whole grain intake in the UK, although higher than in 2000/01, remains low and below that in the US and Danish recommendations in all age classes. Favourable pricing with increased availability of whole-grain foods and education may help to increase whole grain intake in countries without whole-grain recommendations. Teenagers and younger adults may need targeting to help increase whole grain consumption.

Iron (Fe) and zinc (Zn) contents in hexaploid wheat are very low and are further reduced because of the removal of micronutrient-rich bran of wheat grains during milling and processing. Therefore, hexaploid wheat, its wild species and wheat–Aegilops kotschyi substitution lines were evaluated to identify the genome(s) carrying gene(s) for high Fe and Zn concentrations in bran and endosperm fractions of grains. It is reflected from the results that Triticum monococcum (acc. W463) may serve as a promising donor for biofortification of Fe, and Aegilops speltoides (acc. 3804) may serve as a promising donor for biofortification of Zn in the endosperm of cultivated wheat. Further, among the three wheat–Ae. kotschyi substitution lines, the higher concentration of Fe and Zn in endosperm fraction was observed in BC2F4 63-2-13-1. The work on precise transfer of useful gene(s) from 7Uk chromosome of this line is in progress to reduce linkage drag.

Alkylresorcinols (AR) in plasma samples have been suggested to be short- to medium-term biomarkers of whole grain wheat and rye intake. In the present study, we investigated whether AR are present in human adipose tissues, and if content correlated with long-term whole grain bread intake. Furthermore, we investigated if the relative AR homologue composition reflected what has been found previously in the habitual diet of Swedes. Biopsy samples (10–25 mg) from free-living Swedish women (n 20) were analysed by GC–MS. The mean total AR concentration in the samples was 0·54 (sd 0·35) μg/g, ranging from below limit of quantification ( < 0·08 μg/g) to 1·50 μg/g. Whole grain bread intake was significantly correlated with plasma total AR content (r 0·48, P < 0·05), and the C17 : 0/C21 : 0 ratio was 0·35 (sd 0·24), which is similar to what is found in plasma among free-living subjects consuming a mixed whole grain wheat and rye diet. These results suggest that AR in the adipose tissue should be evaluated as a long-term biomarker of whole grain wheat and rye intake.

Subjects with obesity and elevated fasting blood glucose are at high risk of developing type 2 diabetes which may be reduced by a dietary intervention leading to an improvement of insulin resistance. We investigated the potential of a whole-grain based dietary product (WG) with reduced starch content derived from double-fermented wheat during a hypo-energetic diet to positively influence body weight, fasting blood glucose, insulin resistance and lipids in comparison to a nutrient-dense meal replacement product (MR) in a randomized two-way cross-over study with two 4-week treatment periods separated by a 2-week wash-out. Subjects replaced at least two daily meals with WG and MR, respectively, targeting for a consumption of 200 g of either product per day. Total daily energy intake was limited to 7120 kJ. Thirty-one subjects (BMI 33·9 (sd 2·7) kg/m2, fasting blood glucose 6·3 (sd 0·8) mmol/l) completed the study. In both treatment groups body weight ( − 2·5 (sd 2·0) v. − 3·2 (sd 1·6) kg for WG v. MR), fasting blood glucose ( − 0·4 (sd 0·3) v. − 0·5 (sd 0·5) mmol/l), total cholesterol ( − 0·5 (sd 0·5) v. − 0·6 (sd 0·5) mmol/l), TAG ( − 0·3 (sd 0·9) v. − 0·3 (sd 1·2) mmol/l) and homeostasis model assessment (HOMA) insulin resistance score ( − 0·7 (sd 0·8) v. − 1·1 (sd 1·7) μU/ml ×  mmol/l) improved (P < 0·05) with no significant differences between the treatments. After statistical adjustment for the amount of body weight lost, however, the comparison between both groups revealed that fasting serum insulin (P = 0·031) and HOMA insulin resistance score (P = 0·049) improved better with WG than with MR. We conclude that WG favourably influences metabolic risk factors for type 2 diabetes independent from the amount of body weight lost during a hypo-energetic diet.

There is an increasing body of evidence, including that from prospective population studies and epidemiological observational studies, suggesting a strong inverse relationship between increased consumption of wholegrain foods and reduced risk of CVD. This evidence has translated into specific dietary recommendations in the USA to consume at least three servings of whole grain per d, and has informed the development of specific health claims for wholegrain foods both in the USA and in Europe. Wholegrain foods are rich sources of many nutrients and phytochemicals, including complex carbohydrates, dietary fibre, minerals, vitamins, antioxidants and phyto-oestrogens such as lignans. Many of these components are lost from the grain during processing and although some may be replaced (such as in the mandatory fortification of white flour), this practice ignores the possible synergistic effects of the ‘natural’ constituents. The notion that wholegrain foods are simply a source of dietary fibre has been dispelled, although the additional components that contribute to the health benefits have not been clearly identified. In addition, the mechanisms by which wholegrain foods may have their effect are poorly understood. At present there are few strictly-controlled intervention studies that have confirmed a beneficial effect of increased consumption of wholegrain foods, demonstrated the level of consumption required to elicit a beneficial effect or provided evidence of modes of action. Although wholegrain foods are considered amongst the healthiest food choices available, their consumption falls well below current recommendations, which have been based mainly on epidemiological evidence. Well-controlled intervention studies are needed to provide more detailed mechanistic evidence to support the health claims and findings which can be used to develop effective public health strategies to promote whole-grain consumption.

Whole grains are important dietary constituents as they provide a plethora of nutrients and protective chemicals that may have synergistic actions in promoting health. Regular consumption of wholegrain foods has been associated with a reduced risk of several chronic diseases such as CHD and certain cancers, although their exact role in disease prevention is not yet fully elucidated. Studies reporting levels of whole grain consumption reveal that those subjects who include higher levels of whole grain foods in their diets also have many other favourable dietary and lifestyle practices. While the actions of these practices and whole grains may not be mutually exclusive, these variables do not appear to explain the reduction in risk of disease observed for high-whole grain consumers. Actual whole grain consumption levels are extremely low and many practical barriers exist to consumer uptake of these foods. Effective communication of the whole grain health message is an important strategy to increase awareness of the importance of whole grains in the diet. Increasing the variety and availability of acceptable wholegrain foods is also important. Whole grain consumption at breakfast can have an important impact on total daily nutrient intakes. This simple dietary modification is potentially relatively easy to achieve and could greatly contribute to increased whole grain intake for many individuals.