Dietary Intake Of Whole Grains Research Articles

Global trends indicate increasing consumption of dietary sodium and fiber in middle-income countries: A study of 30-year global macrotrends

According to the Global Burden of Disease Study, 3 million deaths were attributable to high sodium intake and low intake of whole grains. With the rapid evolution of the food industry, we hypothesize that dietary intake of sodium has increased and that dietary intake of whole grains or fibers has decreased because of easier access to highly processed food. Country-level data on dietary factors and country income levels from 1990 to 2018 were collected from 3 public databases. The trend of dietary intake was modeled using the linear mixed model accounting for random effects of individual countries. The country-level differences in dietary factors between males and females were calculated, and the trends were also modeled accounting for the random effects of countries. Both males and females consumed increasing amounts of dietary sodium from 1990 to 2018 in high-income, middle- to high-, middle-, and low-income countries. Dietary fiber intake increased in low-to-middle, middle-, and middle-to-high income countries for both men and women over the past 3 decades. Men tend to consume more sodium and less fiber and whole grains in their diets than women, the trend of which is statistically significant in middle-income countries. Over the past 3 decades, the macrotrend of dietary sodium has increased around the globe. To reduce the sodium intake level, nutrition policy should emphasize sodium reduction, especially in high-income, middle- to high-income, middle-income, and low-income countries.

Diet and the gut-lung axis in cystic fibrosis – direct & indirect links

ABSTRACT Cystic fibrosis (CF) is a multisystem, autosomal, recessive disease primarily affecting the lungs, pancreas, gastrointestinal tract, and liver. Whilst there is increasing evidence of a microbial ‘gut-lung axis’ in chronic respiratory conditions, there has been limited analysis of such a concept in CF. We performed a comprehensive dietary and microbiota analysis to explore the interactions between diet, gastrointestinal microbiota, respiratory microbiota, and clinical outcomes in children with CF. Our results demonstrate significant alterations in intestinal inflammation and respiratory and gastrointestinal microbiota when compared to age and gender matched children without CF. We identified correlations between the gastrointestinal and respiratory microbiota, lung function, CF pulmonary exacerbations and anthropometrics, supporting the concept of an altered gut-lung axis in children with CF. We also identified significant differences in dietary quality with CF children consuming greater relative proportions of total, saturated and trans fats, and less relative proportions of carbohydrates, wholegrains, fiber, insoluble fiber, starch, and resistant starch. Our findings position the CF diet as a potential modulator in gastrointestinal inflammation and the proposed gut-lung axial relationship in CF. The dietary intake of wholegrains, fiber and resistant starch may be protective against intestinal inflammation and should be explored as potential therapeutic adjuvants for children with CF.

Higher ultra-processed food intake is associated with higher DNA damage in healthy adolescents.

Ultra-processed food is one of the main contributors to energy supply and consumption in food systems worldwide, and evidence of their detrimental health outcomes in humans is emerging. This study aimed to assess ultra-processed food intake and its association with urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage, in 139 healthy adolescents in Karaj City in Iran. Usual dietary intake was measured using a 168-item validated FFQ. The daily intake of ultra-processed food consumption was determined through the classification of NOVA, and general linear models were used to compare the urinary levels of 8-OHdG/creatinine (ng/mg creatinine) within tertiles of ultra-processed food intake. Adolescents in the higher tertile of ultra-processed food consumption had a significantly higher mean level of urinary 8-OHdG/creatinine in comparison with the lower tertiles in the crude model (Pfor trend: 0·003) and after adjustment for confounding variables, including total energy intake, sex, age, BMI for age Z-score, obesity and physical activity (Pfor trend: 0·004). This association was still significant after adjusting for dietary intake of whole grains, nuts, legumes, the ratio of MUFA:SFA (g/d) and Mediterranean dietary score (Pfor trend: 0·002). More studies are needed to explore the determinants of ultra-processed food supply, demand, consumption and health effects; such studies should be applied to develop evidence-informed policies and regulatory mechanisms to improve children's and adolescents' food environment policymaking and legislation with special attention to ultra-processed food.

Abstract CT138: Increasing dietary rice bran and navy bean intake for colorectal cancer control and prevention: A randomized-controlled pilot investigation

Abstract Adhering to the American Institute for Cancer Research (AICR) Recommendations for Cancer Prevention, including increasing dietary intake of whole grains and beans, has been shown to reduce colorectal cancer (CRC) burden. Dietary rice bran (RB) and navy beans (NB) are examples of these foods with high dietary fiber content and other important phytochemicals that have inhibited colon carcinogenesis in animal and human epidemiological studies. Alongside widespread affordability and accessibility, we formed a community-academic partnership to advance RB and NB dietary chemoprevention research in a pilot phase II study titled BENEFIT: Beans/Bran Enriching Nutritional Eating For Intestinal health Trial (NCT01929122). We established feasibility of increased consumption in CRC survivors and examined changes in dietary intake and gut microflora. Twenty-nine participants completed the 4-week, randomized-controlled dietary intervention that included consuming RB (30g/day), NB powder (35g/day), or neither (control) via study provided meals and snacks. Fasting blood, urine, and stool were collected at baseline, 2-week, and 4-week time points. The amount of RB or NB consumed (ranging from 4-9% daily caloric intake) led to increased dietary fiber, iron, zinc, thiamin, niacin, vitamin B6, folate, and alpha-tocopherol intake, as measured by NutritionistProTM. Stool microbiome analysis from RB group showed significant genus level increases in Methanobrevibacter, Paraprevotella, Ruminococcus, and Bifidobacterium compared to the control group, as well as increased gut bacterial richness and diversity. The NB group increased gut bacterial richness and revealed increases in three previously unidentified species. Plasma, urine, and stool metabolome changes revealed increases in a number of microbial, host, and diet derived metabolites, such as phytosterols, fatty acids, amino acids, bile acids, and small molecule byproducts of carbohydrate metabolism. In addition, human stool metabolite extracts were assessed before and after RB or NB consumption to observe reduced growth of CRC cells. Dietary biomarkers of RB and NB consumption are under investigation and have revealed specific metabolite profiles including pyridoxine (vitamin B6), beta-hydroxyisovaleroylcarnitine and beta-hydroxyisovalerate (RB), and pipecolate and S-methylcysteine (NB). These results support dietary RB or NB modulation of metabolism from digestion, microbiota, and microbial biotransformation. Our pilot findings warrant further evaluation of these specific foods in a larger cohort and for a longer duration of consumption to assess CRC control and prevention markers in the colon tissue. Next phase studies underway include dietary modulation of human colonic inflammation for CRC chemoprevention. Citation Format: Erica C. Borresen, Renee C. Oppel, Dustin G. Brown, Regina J. Brown, Elizabeth P. Ryan. Increasing dietary rice bran and navy bean intake for colorectal cancer control and prevention: A randomized-controlled pilot investigation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT138. doi:10.1158/1538-7445.AM2017-CT138

A Whole-Grain Diet Reduces Cardiovascular Risk Factors in Overweight and Obese Adults: A Randomized Controlled Trial

Background: Increased dietary whole-grain intake may protect against cardiovascular disease (CVD).Objective: The objective was to evaluate the efficacy of whole grains compared with refined grains on body composition, hypertension, and related mediators of CVD in overweight and obese adults.Methods: We conducted a double-blind, randomized, controlled crossover trial in 40 overweight or obese men and women aged <50 y with no known history of CVD. Complete whole-grain and refined-grain diets were provided for two 8-wk periods, with a 10-wk washout between diets. Macronutrient composition was matched, except for the inclusion of either whole grains or refined grains (50 g/1000 kcal in each diet). Measurements included blood pressure, body composition, blood lipids and adiponectin, and markers of inflammation and glycemia.Results: Thirty-three participants (6 men and 27 women) completed the trial [mean ± SD age: 39 ± 7 y; mean ± SD body mass index (in kg/m2): 33.1 ± 4.3]. Decreases in diastolic blood pressure were −5.8 mm Hg (95% CI: −7.7, −4.0 mm Hg) after the whole-grain diet and −1.6 mm Hg (95% CI: −4.4, 1.3 mm Hg) after the control diet (between effect, P = 0.01). Decreases in plasma adiponectin were −0.1 (95% CI: −0.9, 0.7) after the whole-grain diet and −1.4 (95% CI: −2.6, −0.3) after the control diet (between effect, P = 0.05). Decreases in diastolic blood pressure correlated with the circulating adiponectin concentration (r = 0.35, P = 0.04). Substantial reductions in body weight, fat loss, systolic blood pressure, total cholesterol, and LDL cholesterol were observed during both diet periods, with no relevant difference between them.Conclusions: The improvement in diastolic blood pressure was >3-fold greater in overweight and obese adults when they consumed a whole-grain compared with a refined-grain diet. Because diastolic blood pressure predicts mortality in adults aged <50 y, increased whole-grain intake may provide a functional approach to control hypertension. This may benefit patients at risk of vascular-related morbidity and mortality. This trial was registered at http://clinicaltrials.gov as NCT01411540.

Nutrimetabolomics fingerprinting to identify biomarkers of whole grain wheat intake

Increased whole grain (WG) consumption has been inversely associated with the risk for developing some diet‐related disorders, such as type 2 diabetes, obesity, cancer, and cardiovascular diseases. Many epidemiological studies, however, have failed to generate consistent results on this topic due to a lack of accurate tools to assess dietary intake of whole grains. Nutritional epidemiology research needs more reliable and quantitative methods for measuring dietary intake of specific foods. Using a targeted LC/MS based metabolomic approach, we established the metabolic fingerprints of the major phytochemicals in WG wheat in human urine including metabolites of alkylresorcinols, benzoxazinoids, lignans, and phytosterols, as well as microbial‐derived metabolites. Using a non‐targeted LC/MS based global metabolomic approach, we investigated the impact of WG wheat bread intake on the endogenous urinary metabolome. Metabolic profiling revealed a number of differences relating to the consumption of WG wheat bread vs. refined grain wheat bread, such as 3,5‐dihydroxybenzoic acid, 2‐aminophenol sulfate, ferulic acid 4‐sulfate, 2‐acetamidophenol sulfate, and cysteine. Using the targeted and non‐targeted nutrimetabolomic approaches, we are able to develop multiple metabolites as the potential biomerkers of WG wheat intake.Support or Funding InformationUSDA‐NIFA grant 2012‐38821‐20012 to S. Sang

The Cholesterol‐Lowering Effect of Statins is Potentiated by Whole Grains Intake. The Polish Norwegian Study (PONS)

IntroductionAdequate whole grains (WG) dietary intake is advocated for cardiovascular health. Statins represent the cornerstone of medical control of hypercholesterolemia. Whether there is an interaction between WG intake and statins, has not been fully explored in ‘real life’ settings. Our objective was to assess the interaction between statin use and whole grains fiber intake on plasma lipids.MethodsWe used cross‐sectional data of 12754 participants, ages 45 to 64 years, in an ongoing cohort study in Poland. Statin use during the last 30 days was recorded by trained nurses. WG intake was estimated from a food frequency questionnaire assessing participants’ habitual food intake in the past year. Plasma total, LDL, HDL cholesterol, triglycerides and glucose were measured in a fasting state. Multivariable linear and logistic regression models were used for analyses.ResultsThere were 1728 (13.55%) statin users. High WG grain intake (at or above the recommended levels of ≥3 oz/d) was achieved by 2835 (22.23%) participants. Those taking statins, had lower mean (95%CI) plasma lipid levels if they had a high WG intake, even after adjusting for age, sex, education, total caloric intake, various dietary nutrients intake, physical activity, smoking, glucose levels, BMI and prevalent CVD: Cholesterol: 185.13 mg/dL (181.65–188.60) vs. 190.14 mg/dL (188.02–192.27); non‐HDL cholesterol: 127.26 mg/dL (123.83–130.71) vs. 133.02 mg/dL (130.92–135.12); LDL: 104.42 mg/dL (101.37–107.45) vs. 108.54 mg/dL(106.69–110.40). High vs. low WG intake did not have an effect among those not taking statins, nor on triglyceride or HDL levels. In fully adjusted models, statin users with a high WG intake had 33% lower odds of having a cholesterol level ≥ 240 mg/dL and 38% lower odds of having a non‐HDL cholesterol ≥130 mg/dL, compared to statin users with low WG intake.ConclusionWe found a potentiation of effect of statins by whole grain dietary intake on plasma lipid levels. Given that the current paradigm on controlling plasma lipids is that “lower is better” and that the uptitration of statins can be potentially toxic, the interaction with the dietary intake of WG has potential clinical significance.Support or Funding InformationFINANCIAL DISCLOSURES: The data collection was supported by a grant from the Polish‐Norwegian Research Fund (PNRF‐228‐AI‐1/07).

Urinary alkylresorcinol metabolites as a biomarker of dietary wholegrain intake and of compliance in a randomised dietary intervention trial: results from the CRESSIDA Study

Urinary alkylresorcinol metabolites as a biomarker of dietary wholegrain intake and of compliance in a randomised dietary intervention trial: results from the CRESSIDA Study

고지방식이로 유도한 지방간 마우스에서 기장 첨가식이가 지방간 및 인슐린 저항성에 미치는 영향

비알코올성 지방간은 인슐린저항성을 근간으로 하는 대사증후군의 원인으로 생각되고 있으며 최근 그 발병율이 증가하고 있다. 본 연구진은 기장 열수추출물을 식이에 첨가하여 고지방식에 의해 인위적으로 지방간을 유도한 마우스에게 섭취시킨 후 혈청 내 생물학적 수치와 간조직 검사를 통하여 비알코올성 지방간 억제 효과를 검토하였다. 그 결과, 식이섭취량은 차이가 없었으나 간조직 무게가 1% 및 2% 기장 열수추출물 첨가식이군에서 유의적으로 감소하였고(p<0.05) 간조직 내 지방 축적이 유의적으로 감소하였음을 확인하였다. 또한 기장 열수추출물 첨가식이군의 경우 고지방식 대조군에 비해 혈청 중성지방 및 총 콜레스테롤이 감소하였고(p<0.05), HDL과 HDL-/총 콜레스테롤의 비율이 유의적으로 증가하여(p<0.05) 혈액의 지질 조성이 개선되었음을 알 수 있었다. HOMA-IR 및 포도당 내성 검사 결과 2% 기장 열수추출물 첨가군의 경우 이들 모두 유의적으로 감소하여 고지방식에 의한 인슐린 저항성 및 당흡수 부전을 기장열수추출물이 완화시켰다(p<0.05). 한편 간조직에서 지방산 대사와 관련된 인자들의 유전자 발현을 측정한 결과 지방산 합성에 관여하는 L-FABP와 SCD1은 2% 기장 열수추출물 섭취군에서 유의적으로 감소하였고(p<0.05) 지방산 산화와 관련된 PPARα는 1% 및 2% 기장 열수추출물 섭취군에서 모두 유의적으로 증가하였다(p<0.05). 이상의 혈청 및 조직의 생물학적 수치와 간조직 검사 결과를 미루어 볼 때 기장 열수추출물 첨가 식이는 고지방식이에 의해 유도된 마우스의 비알코올성 지방간 치유 혹은 예방에 긍정적으로 기여할 수 있음을 시사해 준다.

Wholegrain oat-based cereals have prebiotic potential and low glycaemic index

Population studies show a positive association between increased dietary intake of wholegrains and reduced risk of cardiometabolic disorders. Consumption of wholegrain food has been associated with lower blood glucose and therefore may contribute to a low-glycaemic load diet. The ability to mediate a prebiotic modulation of gut microbiota has recently been suggested to have an inverse correlation with risk of cardiometabolic disease. To date very little work has been carried out on the functionality of wholegrain breakfast cereals in terms of glycaemic response or impact on gut microbiota. An investigation into identifying wholegrain-based breakfast cereals demonstrating both low glycaemic index (GI) and prebiotic attributes was performed. After in vitro digestion, cereal samples were supplemented to pH-controlled anaerobic batch cultures of the human faecal microbiota. Total bacteria populations increased significantly (P<0·05) in all treated cultures, and the fermentation of a wholegrain oat cluster cereal was associated with proliferation of the Bifidobacterium genus (P=0·02). Smaller, but significant increases in the Bifidobacterium genus were observed for a further four oat-based cereals. Significant increases in the Lactobacillus-Enterococcus group were observed for granola (P=0·01), 100% wholegrain aggregate (P=0·04) and 70% wholegrain loops (P=0·01). Cereals demonstrating prebiotic potential were selected for GI determination in twelve healthy subjects. The wholegrain oat aggregate cereal achieved the lowest GI value (40), three other cereals ranged between 44 and 74, with instant porridge resulting in a GI value similar to the standard glucose control. The present study suggests that wholegrain oat-based breakfast cereals may be prebiotics and have the potential to have low GI.

Hog millet (Panicum miliaceumL.)-supplemented diet ameliorates hyperlipidemia and hepatic lipid accumulation in C57BL/6J-ob/obmice

Dietary intake of whole grains reduces the incidence of chronic diseases such as obesity, diabetes, cardiovascular disease, and cancer. In an earlier study, we showed that Panicum miliaceum L. extract (PME) exhibited the highest anti-lipogenic activity in 3T3-L1 cells among extracts of nine different cereal grains tested. In this study, we hypothesized that PME in the diet would lead to weight loss and augmentation of hyperlipidemia by regulating fatty acid metabolism. PME was fed to ob/ob mice at 0%, 0.5%, or 1% (w/w) for 4 weeks. After the experimental period, body weight changes, blood serum and lipid profiles, hepatic fatty acid metabolism-related gene expression, and white adipose tissue (WAT) fatty acid composition were determined. We found that the 1% PME diet, but not the 0.5%, effectively decreased body weight, liver weight, and blood triglyceride and total cholesterol levels (P < 0.05) compared to obese ob/ob mice on a normal diet. Hepatic lipogenic-related gene (PPARα, L-FABP, FAS, and SCD1) expression decreased, whereas lipolysis-related gene (CPT1) expression increased in animals fed the 1% PME diet (P < 0.05). Long chain fatty acid content and the ratio of C18:1/C18:0 fatty acids decreased significantly in adipose tissue of animals fed the 1% PME diet (P < 0.05). Serum inflammatory mediators also decreased significantly in animals fed the 1% PME diet compared to those of the ob/ob control group (P < 0.05). These results suggest that PME is useful in the chemoprevention or treatment of obesity and obesity-related disorders.

Effects ofPanicum miliaceumL. extract on adipogenic transcription factors and fatty acid accumulation in 3T3-L1 adipocytes

The dietary intake of whole grains is known to reduce the incidence of chronic diseases such as obesity, diabetes, cardiovascular disease, and cancer. To investigate whether there are anti-adipogenic activities in various Korean cereals, we assessed water extracts of nine cereals. The results showed that treatment of 3T3-L1 adipocytes with Sorghum bicolor L. Moench, Setaria italica Beauvois, or Panicum miliaceum L. extract significantly inhibited adipocyte differentiation, as determined by measuring oil red-O staining, triglyceride accumulation, and glycerol 3-phosphate dehydrogenase activity. Among the nine cereals, P. miliaceum L. showed the highest anti-adipogenic activity. The effects of P. miliaceum L. on mRNA expression of peroxisome proliferator-activated receptor-γ, sterol regulatory element-binding protein 1, and the CCAAT/enhancer binding protein-α were evaluated, revealing that the extract significantly decreased the expression of these genes in a dose-dependent manner. Moreover, P. miliaceum L. extract changed the ratio of monounsaturated fatty acids to saturated fatty acids in adipocytes, which is related to biological activity and cell characteristics. These results suggest that some cereals efficiently suppress adipogenesis in 3T3-L1 adipocytes. In particular, the effect of P. miliaceum L. on adipocyte differentiation is associated with the downregulation of adipogenic genes and fatty acid accumulation in adipocytes.

Dietary glycemic index, glycemic load, insulin index, fiber and whole-grain intake in relation to risk of prostate cancer.

Insulin may play a role in prostate cancer tumorigenesis. Postprandial blood glucose and insulin responses of foods depend importantly on the carbohydrate quality and quantity, represented by glycemic index (GI), glycemic load (GL), fiber and whole-grain content, but are also influenced by intake of protein and other characteristics. The recently developed insulin index (II) quantifies the postprandial insulin secretion, also taking into account these additional characteristics. We investigated the association between dietary GI, GL, II, fiber, and whole grains and risk of total prostate cancer (n=5,112) and subgroups of prostate cancer as defined by stage or grade in 49,934 male participants of the Health Professionals Follow-up Study. Multivariate adjusted hazard ratios (HR) and 95% confidence intervals (95% CI) were estimated using Cox proportional hazards regression. Dietary GI, GL, II, or fiber was not associated with risk of total or subgroups of prostate cancer. We observed a positive association between dietary intake of whole grains and total prostate cancer (HR highest versus lowest quintile 1.13, 95% CI 1.03-1.24), which was attenuated after restriction to PSA-screened participants (HR 1.03, 95% CI 0.91-1.17). These results suggest that long-term exposure to a diet with a high insulin response does not affect prostate cancer incidence.

Interactions of dietary whole-grain intake with fasting glucose- and insulin-related genetic loci in individuals of European descent: a meta-analysis of 14 cohort studies.

OBJECTIVEWhole-grain foods are touted for multiple health benefits, including enhancing insulin sensitivity and reducing type 2 diabetes risk. Recent genome-wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) associated with fasting glucose and insulin concentrations in individuals free of diabetes. We tested the hypothesis that whole-grain food intake and genetic variation interact to influence concentrations of fasting glucose and insulin.RESEARCH DESIGN AND METHODSVia meta-analysis of data from 14 cohorts comprising ∼48,000 participants of European descent, we studied interactions of whole-grain intake with loci previously associated in GWAS with fasting glucose (16 loci) and/or insulin (2 loci) concentrations. For tests of interaction, we considered a P value <0.0028 (0.05 of 18 tests) as statistically significant.RESULTSGreater whole-grain food intake was associated with lower fasting glucose and insulin concentrations independent of demographics, other dietary and lifestyle factors, and BMI (β [95% CI] per 1-serving-greater whole-grain intake: −0.009 mmol/l glucose [−0.013 to −0.005], P < 0.0001 and −0.011 pmol/l [ln] insulin [−0.015 to −0.007], P = 0.0003). No interactions met our multiple testing–adjusted statistical significance threshold. The strongest SNP interaction with whole-grain intake was rs780094 (GCKR) for fasting insulin (P = 0.006), where greater whole-grain intake was associated with a smaller reduction in fasting insulin concentrations in those with the insulin-raising allele.CONCLUSIONSOur results support the favorable association of whole-grain intake with fasting glucose and insulin and suggest a potential interaction between variation in GCKR and whole-grain intake in influencing fasting insulin concentrations.

Whole-grain consumption and transcription factor-7-like 2 (TCF7L2) rs7903146: gene–diet interaction in modulating type 2 diabetes risk

Whole grains are known to influence postprandial glucose response and insulin demand and are inversely associated with diabetes risk. Genetic variation of the transcription factor-7-like 2 encoding gene (TCF7L2) is assumed to promote an early insulin secretory defect and has been consistently attributed to the risk of developing type 2 diabetes. The present study examined the hypothesis that the protective effect of whole grains might be attenuated in the presence of the rs7903146 risk-conferring T-allele. We employed a case-cohort study of 2318 randomised individuals and 724 incident type 2 diabetes cases from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam cohort. Multivariate Cox regression was used to estimate relative risks of diabetes including product terms testing for the genotype-specific effect modification of dietary whole grain. Dietary intake of whole grains was assessed by a validated FFQ. The TCF7L2 rs7903146 T-allele was associated with type 2 diabetes (hazard ratio=1.51; 95 % CI 1.21, 1.87) and modified the inverse association between whole-grain intake and diabetes risk (P=0.016 for interaction). While whole-grain intake was inversely associated with diabetes risk among rs7903146 CC homozygote carriers (hazard ratio for 50 g portion per d=0.86; 95 % CI 0.75, 0.99), the T-allele negated the protective effect of whole-grain intake (hazard ratio among T-allele carriers for 50 g portion per d=1.08; 95 % CI 0.96, 1.23). These data provide evidence that the beneficial effect of whole-grain intake on diabetes risk is modified by TCF7L2 rs7903146.

Whole-grain wheat breakfast cereal has a prebiotic effect on the human gut microbiota: a double-blind, placebo-controlled, crossover study

Epidemiological studies have shown an inverse association between dietary intake of whole grains and the risk of chronic disease. This may be related to the ability to mediate a prebiotic modulation of gut microbiota. However, no studies have been conducted on the microbiota modulatory capability of whole-grain (WG) cereals. In the present study, the impact of WG wheat on the human intestinal microbiota compared to wheat bran (WB) was determined. A double-blind, randomised, crossover study was carried out in thirty-one volunteers who were randomised into two groups and consumed daily 48 g breakfast cereals, either WG or WB, in two 3-week study periods, separated by a 2-week washout period. Numbers of faecal bifidobacteria and lactobacilli (the target genera for prebiotic intake), were significantly higher upon WG ingestion compared with WB. Ingestion of both breakfast cereals resulted in a significant increase in ferulic acid concentrations in blood but no discernible difference in faeces or urine. No significant differences in faecal SCFA, fasting blood glucose, insulin, total cholesterol (TC), TAG or HDL-cholesterol were observed upon ingestion of WG compared with WB. However, a significant reduction in TC was observed in volunteers in the top quartile of TC concentrations upon ingestion of either cereal. No adverse intestinal symptoms were reported and WB ingestion increased stool frequency. Daily consumption of WG wheat exerted a pronounced prebiotic effect on the human gut microbiota composition. This prebiotic activity may contribute towards the beneficial physiological effects of WG wheat.

Alkylresorcinols from Whole-Grain Wheat and Rye Are Transported in Human Plasma Lipoproteins

Alkylresorcinols with alkyl chains C17:0-C25:0 are abundant in whole-grain wheat and rye. Concentrations in human plasma have been suggested to be biomarkers of dietary whole-grain intake. We measured human plasma, erythrocyte, and lipoprotein alkylresorcinol concentrations and alkylresorcinol homolog distribution, and evaluated the use of plasma alkylresorcinol concentration as a dietary biomarker of whole-grain intake compared with serum enterolactone. A total of 15 subjects (8 women) consumed whole-grain wheat or whole-grain rye crisp bread (∼100 g/d) in a crossover design for 1 wk. The test bread periods were preceded by 1-wk periods of consuming refined wheat bread. Plasma, erythrocyte, lipoprotein alkylresorcinol, and serum enterolactone concentrations were measured before and after each period, and plasma alkylresorcinols and serum enterolactone were measured after habitual diet intake before and 1 wk after the trial. Plasma alkylresorcinols are transported in lipoproteins with VLDL and HDL being the main carriers. AR concentrations in plasma, erythrocytes, and lipoproteins were increased (P < 0.05) by whole-grain wheat bread and even more so with rye crisp bread, although interindividual variation was high. The alkylresorcinol homolog C17:0 to C21:0 ratio in plasma was higher after the whole-grain rye diet period compared with the whole-grain wheat diet period (P < 0.05). Serum enterolactone concentrations were increased significantly by whole-grain rye intake only in men. This is the first report to show that alkylresorcinols in human plasma are mainly transported in lipoproteins. The plasma alkylresorcinol C17:0 to C21:0 ratio reflects intake of whole-grain wheat and rye, and the plasma total alkylresorcinol concentration appears to be a useful biomarker of whole-grain cereal intake.

Dietary Intake of Whole Grains

Objective: The objective of this study was to provide national estimates of whole-grain intake in the United States, identify major dietary sources of whole grains and compare food and nutrient intakes of whole-grain consumers and nonconsumers.Methods: Data were collected from 9,323 individuals age 20 years and older in USDA’s 1994–96 Continuing Survey of Food Intakes by Individuals through in-person interviews on two non-consecutive days using a multiple-pass 24-hour recall method. Foods reported by respondents were quantified in servings as defined by the Food Guide Pyramid using a new database developed by the USDA. Whole-grain and nonwhole-grain servings were determined based on the proportion, by weight, of the grain ingredients in each food that were whole grain and nonwhole grain. Sampling weights were applied to provide national probability estimates adjusted for differential rates of selection and nonresponse. Then, t tests were used to assess statistically significant differences in intakes of nutrients and food groups by whole-grain consumers and nonconsumers.Results: According to the 1994–96 survey, U.S. adults consumed an average of 6.7 servings of grain products per day; 1.0 serving was whole grain. Thirty-six percent averaged less than one whole-grain serving per day based on two days of intake data, and only eight percent met the recommendation to eat at least three servings per day. Yeast breads and breakfast cereals each provided almost one-third of the whole-grain servings, grain-based snacks provided about one-fifth, and less than one-tenth came from quick breads, pasta, rice, cakes, cookies, pies, pastries and miscellaneous grains. Whole-grain consumers had significantly better nutrient profiles than nonconsumers, including higher intakes of vitamins and minerals as percentages of 1989 Recommended Dietary Allowances and as nutrients per 1000 kilocalories, and lower intakes of total fat, saturated fat and added sugars as percentages of food energy. Consumers were significantly more likely than nonconsumers to meet Pyramid recommendations for the grain, fruit and dairy food groups.Conclusion: Consumption of whole-grain foods by U.S. adults falls well below the recommended level. A large proportion of the population could benefit from eating more whole grain, and efforts are needed to encourage consumption.