scholarly journals The Effect of Whole-Grain Intake on Biomarkers of Subclinical Inflammation: A Comprehensive Meta-analysis of Randomized Controlled Trials

Author(s):  
Sepideh Rahmani ◽  
Omid Sadeghi ◽  
Mehdi Sadeghian ◽  
Narges Sadeghi ◽  
Bagher Larijani ◽  
...  

ABSTRACT Findings on the effect of whole-grain consumption on inflammatory biomarkers are conflicting. This study aimed to summarize available studies on the effects of whole-grain consumption on inflammatory biomarkers in adults. Online databases including PubMed, Scopus, ISI Web of Science, and Google Scholar were searched for relevant studies published up to January 2018, using relevant keywords. We included randomized controlled trials (RCTs) investigating the effect of whole-grain foods or diets high in whole-grain foods on markers of inflammation. Studies were selected if they had a control diet low in whole grains or diets without whole grains, whether calorie restricted or not. We did not include studies that examined the effect of individual grain components, including bran or germ, or fiber-based diets. Overall, 14 RCTs, with 1238 individuals aged ≥18 y, were included. Pooling 13 effect sizes from 11 RCTs on serum C-reactive protein (CRP) concentrations, we found no significant effect of whole-grain consumption on serum CRP concentrations [weighted mean difference (WMD): −0.29 mg/L; 95% CI: −1.10, 0.52 mg/L]. However, the beneficial effects of whole-grain intake on serum CRP concentrations were observed in studies in individuals with elevated serum concentrations of CRP and studies with isocaloric diets. Combining 11 effect sizes from 10 RCTs, we found no significant effect of whole-grain consumption on serum IL-6 concentrations (WMD: −0.08 pg/mL; 95% CI: −0.27, 0.11 pg/mL). Nevertheless, we observed a significant effect of whole-grain consumption on serum IL-6 concentrations in studies in unhealthy individuals. A nonsignificant effect of whole-grain intake on circulating serum TNF-α concentrations was also seen when we summarized effect sizes from 7 RCTs (WMD: −0.06 pg/mL; 95% CI: −0.25, 0.14 pg/mL). Such a nonsignificant effect was observed for serum concentrations of plasminogen activator inhibitor-1 (PAI-1) (WMD: −3.59; 95% CI: −1.25, 8.44 kU/L). Unlike observational studies, we found no significant effect of whole-grain consumption on serum concentrations of inflammatory cytokines, including serum concentrations of CRP, IL-6, TNF-α, and PAI-1. However, beneficial effects of whole grains were found in some subgroups. Given the high between-study heterogeneity, deriving firm conclusions is difficult.

2002 ◽  
Vol 88 (2) ◽  
pp. 111-116 ◽  
Author(s):  
David R. Jacobs ◽  
Mark A. Pereira ◽  
Katariina Stumpf ◽  
Joel J. Pins ◽  
Herman Adlercreutz

Both intake of whole grain and higher levels of serum enterolactone have been related to reduced risk for CHD and some cancers. Because lignans are prevalent in the outer layers of grains, these findings may be related. We carried out a crossover feeding study in which overweight, hyperinsulinaemic, non-diabetic men (n5) and women (n6) ate, in random order, wholegrain foods or refined-grain foods in a diet with 30% energy from fat. The dominant whole grain was wheat, followed by oats and rice. All food was supplied by the investigators and each diet lasted for 6 weeks, with an intervening washout period of 6–9 weeks. Serum enterolactone concentrations were higher when eating the wholegrain than the refined-grain diet by 6·2 (within person SE 1·7) nmol/l (P=0·0008). Most of the increase in serum enterolactone when eating the wholegrain diet occurred within 2 weeks, though the serum enterolactone difference between wholegrain and refined-grain diets continued to increase through 6 weeks. Serum enterolactone concentrations can be raised by eating a diet rich in whole grains.


BMJ ◽  
2020 ◽  
pp. m2206 ◽  
Author(s):  
Yang Hu ◽  
Ming Ding ◽  
Laura Sampson ◽  
Walter C Willett ◽  
JoAnn E Manson ◽  
...  

Abstract Objective To examine the associations between the intake of total and individual whole grain foods and the risk of type 2 diabetes. Design Prospective cohort studies. Setting Nurses’ Health Study (1984-2014), Nurses’ Health Study II (1991-2017), and Health Professionals Follow-Up Study (1986-2016), United States. Participants 158 259 women and 36 525 men who did not have type 2 diabetes, cardiovascular disease, or cancer at baseline. Main outcome measures Self-reports of incident type 2 diabetes by participants identified through follow-up questionnaires and confirmed by a validated supplementary questionnaire. Results During 4 618 796 person years of follow-up, 18 629 participants with type 2 diabetes were identified. Total whole grain consumption was categorized into five equal groups of servings a day for the three cohorts. After adjusting for lifestyle and dietary risk factors for diabetes, participants in the highest category for total whole grain consumption had a 29% (95% confidence interval 26% to 33%) lower rate of type 2 diabetes compared with those in the lowest category. For individual whole grain foods, pooled hazard ratios (95% confidence intervals) for type 2 diabetes in participants consuming one or more servings a day compared with those consuming less than one serving a month were 0.81 (0.77 to 0.86) for whole grain cold breakfast cereal, 0.79 (0.75 to 0.83) for dark bread, and 1.08 (1.00 to 1.17) for popcorn. For other individual whole grains with lower average intake levels, comparing consumption of two or more servings a week with less than one serving a month, the pooled hazard ratios (95% confidence intervals) were 0.79 (0.75 to 0.83) for oatmeal, 0.88 (0.82 to 0.94) for brown rice, 0.85 (0.80 to 0.90) for added bran, and 0.88 (0.78 to 0.98) for wheat germ. Spline regression showed a non-linear dose-response association between total whole grain intake and the risk of type 2 diabetes where the rate reduction slightly plateaued at more than two servings a day (P<0.001 for curvature). For whole grain cold breakfast cereal and dark bread, the rate reduction plateaued at about 0.5 servings a day. For consumption of popcorn, a J shaped association was found where the rate of type 2 diabetes was not significantly raised until consumption exceeded about one serving a day. The association between higher total whole grain intake and lower risk of type 2 diabetes was stronger in individuals who were lean than in those who were overweight or obese (P=0.003 for interaction), and the associations did not vary significantly across levels of physical activity, family history of diabetes, or smoking status. Conclusion Higher consumption of total whole grains and several commonly eaten whole grain foods, including whole grain breakfast cereal, oatmeal, dark bread, brown rice, added bran, and wheat germ, was significantly associated with a lower risk of type 2 diabetes. These findings provide further support for the current recommendations of increasing whole grain consumption as part of a healthy diet for the prevention of type 2 diabetes.


2008 ◽  
Vol 11 (8) ◽  
pp. 849-859 ◽  
Author(s):  
Teri L Burgess-Champoux ◽  
Hing Wan Chan ◽  
Renee Rosen ◽  
Len Marquart ◽  
Marla Reicks

AbstractObjectiveThe aim of the present study was to pilot-test a school-based intervention designed to increase consumption of whole grains by 4th and 5th grade children.DesignThis multi-component school-based pilot intervention utilised a quasi-experimental study design (intervention and comparison schools) that consisted of a five-lesson classroom curriculum based on Social Cognitive Theory, school cafeteria menu modifications to increase the availability of whole-grain foods and family-oriented activities. Meal observations of children estimated intake of whole grains at lunch. Children and parents completed questionnaires to assess changes in knowledge, availability, self-efficacy, usual food choice and role modelling.Setting/sampleParent/child pairs from two schools in the Minneapolis metropolitan area; 67 in the intervention and 83 in the comparison school.ResultsWhole-grain consumption at the lunch meal increased by 1 serving (P< 0·0001) and refined-grain consumption decreased by 1 serving for children in the intervention school compared with the comparison school post-intervention (P< 0·001). Whole-grain foods were more available in the lunches served to children in the intervention school compared with the comparison school post-intervention (P< 0·0001). The ability to identify whole-grain foods by children in both schools increased, with a trend towards a greater increase in the intervention school (P= 0·06). Parenting scores for scales for role modelling (P< 0·001) and enabling behaviours (P< 0·05) were significantly greater for parents in the intervention school compared with the comparison school post-intervention.ConclusionsThe multi-component school-based programme implemented in the current study successfully increased the intake of whole-grain foods by children.


2018 ◽  
Vol 33 (1) ◽  
pp. 79-86
Author(s):  
Hayden Stewart ◽  
Patrick W. McLaughlin ◽  
Diansheng Dong ◽  
Elizabeth Frazão

Purpose: The US Department of Agriculture’s Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) seeks to improve the health of participating women and children by providing nutrition education and a monthly package of supplemental foods including whole grain bread and cereal. While some studies confirm that participants consume more whole grains, others find no effect. In this study, we hypothesize that the positive association between WIC and whole grains is being reduced in size and consistency by several factors. Design/Setting/Participants: American households were surveyed about their food purchases. Overall response rate was 45.6%. A total of 4826 households completed the survey including 471 WIC households. Measures: The survey recorded households’ purchases of refined and whole grains in bread and cereal over 1 week. Analysis: T tests were used to compare the bread and cereal purchases of WIC and eligible, non-WIC households. Probit models were also estimated to assess a WIC household’s likelihood to choose whole grain foods when using benefits versus other payment methods. Results: On average, WIC households acquired more whole grains in bread than eligible, non-WIC households (1.33 vs 0.72 ounce equivalents per household member aged 1 year or older; P < .05). No difference is found for cereal ( P > .10). Moreover, when using payment methods other than WIC benefits, WIC participants are 19% less likely than other households to choose whole grain bread ( P < .05) and 20% less likely to choose a whole grain cold cereal ( P < .05), which suggests that WIC-provided foods may replace some whole grains participants would otherwise buy for themselves. Conclusion: WIC is positively associated with whole grains. However, the association is stronger for bread than cereal. Moreover, foods provided through the program may partially replace whole grains that WIC households would otherwise buy for themselves.


2019 ◽  
Vol 121 (8) ◽  
pp. 914-937 ◽  
Author(s):  
Eden M. Barrett ◽  
Marijka J. Batterham ◽  
Sumantra Ray ◽  
Eleanor J. Beck

AbstractWhole grain intake is associated with lower CVD risk in epidemiological studies. It is unclear to what extent cereal fibre, located primarily within the bran, is responsible. This review aimed to evaluate association between intake of whole grain, cereal fibre and bran and CVD risk. Academic databases were searched for human studies published before March 2018. Observational studies reporting whole grain and cereal fibre or bran intake in association with any CVD-related outcome were included. Studies were separated into those defining whole grain using a recognised definition (containing the bran, germ and endosperm in their natural proportions) (three studies, seven publications) and those using an alternative definition, such as including added bran as a whole grain source (eight additional studies, thirteen publications). Intake of whole grain, cereal fibre and bran were similarly associated with lower risk of CVD-related outcomes. Within the initial analysis, where studies used the recognised whole grain definition, results were less likely to show attenuation after adjustment for cereal fibre content. The fibre component of grain foods appears to play an important role in protective effects of whole grains. Adjusting for fibre content, associations remained, suggesting that additional components within the whole grain, and the bran component, may contribute to cardio-protective association. The limited studies and considerable discrepancy in defining and calculating whole grain intake limit conclusions. Future research should utilise a consistent definition and methodical approach of calculating whole grain intake to contribute to a greater body of consistent evidence surrounding whole grains.


Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3045
Author(s):  
Nirmala Prasadi V. P. ◽  
Iris J. Joye

The consumption of whole grain products is often related to beneficial effects on consumer health. Dietary fibre is an important component present in whole grains and is believed to be (at least partially) responsible for these health benefits. The dietary fibre composition of whole grains is very distinct over different grains. Whole grains of cereals and pseudo-cereals are rich in both soluble and insoluble functional dietary fibre that can be largely classified as e.g., cellulose, arabinoxylan, β-glucan, xyloglucan and fructan. However, even though the health benefits associated with the consumption of dietary fibre are well known to scientists, producers and consumers, the consumption of dietary fibre and whole grains around the world is substantially lower than the recommended levels. This review will discuss the types of dietary fibre commonly found in cereals and pseudo-cereals, their nutritional significance and health benefits observed in animal and human studies.


2016 ◽  
Vol 88 (10) ◽  
pp. 35-41 ◽  
Author(s):  
V V Klimontov ◽  
N V Tyan ◽  
O N Fazullina ◽  
N E Myakina ◽  
N B Orlov ◽  
...  

Aim. To estimate the relationships between the serum concentrations of acute-phase proteins (APPs) and adipocytokines, body composition (BC), and blood glucose (BG) fluctuations in women with type 2 diabetes mellitus (T2DM). Subjects and methods. A total of 165 women with T2DM and 22 with a normal body mass index (BMI) at the age of 40 to 70 years were examined. The concentrations of high-sensitivity C-reactive protein (hs-CRP) and acid α1-glycoprotein (α1-AGP) were determined by ELISA. The levels of interleukins 6, 8, and 18 (IL-6, IL-8, IL-18), tumor necrosis factor-α (TNF-α), and plasminogen activator inhibitor type 1 (PAI-1) were measured by a multiplex analysis. Dual energy X-ray absorptiometry was used to estimate BC parameters. BG fluctuations were estimated via continuous glucose monitoring. Results. The levels of hs-CRP, α1-AGP, IL-6, IL-8, IL-18, TNF-α, and PAI-1 were significantly higher in the obese women with T2DM than those in the control group. In the diabetic normal weight women, only hs-CRP, α1-AGP, and IL-8 concentrations exceeded those in the controls. The level of hs-CRP (other than α1-AGP) correlated positively with BMI, the mass of adipose tissue, body trunk (android), and gynoid fats. A multivariate regression analysis showed that adipose tissue mass and trunk fat proportion were independent predictors of hs-CRP levels. The concentrations of IL-6, IL-8, IL-18, PAI-1, and TNF-α correlated positively with waist-to-hip ratio, but demonstrated no associations with BMI and BC. Only the serum α1-AGP level showed a positive association with mean BG and its variability parameters. Conclusion. In the women with T2DM, the serum concentrations of APPs and adipocytokines correlate differently with the mass of adipose tissue, its distribution, and BG fluctuations. The findings indicate the multifactorial genesis of chronic inflammation in these patients.


Nutrients ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 138
Author(s):  
Jan-Willem van der Kamp ◽  
Julie Miller Jones ◽  
Kevin B. Miller ◽  
Alastair B. Ross ◽  
Chris J. Seal ◽  
...  

Proposed global definitions of whole grain as an ingredient and whole grain food are presented by the authors on behalf of the Whole Grain Initiative. Whole grains are an important pillar of healthy and sustainable diets. Internationally accepted credible definitions of whole grains as food ingredients and whole-grain foods are necessary to ensure that all global stakeholders have shared standards, and that consumers find them clear, credible, and useful. Based on widely accepted, existing definitions and new developments, the Definitions Working Group of the global Whole Grain Initiative, with experts from academia, government agencies and industry, developed definitions for global application. The key statements of the definition documents are as follows: “Whole grains shall consist of the intact, ground, cracked, flaked or otherwise processed kernel after the removal of inedible parts such as the hull and husk; all anatomical components, including the endosperm, germ, and bran must be present in the same relative proportions as in the intact kernel” and “A whole-grain food shall contain at least 50% whole-grain ingredients based on dry weight. Foods containing 25–50% whole-grain ingredients based on dry weight, may make a front-of-pack claim on the presence of whole grain but cannot be designated ‘whole grain’ in the product name”. The definition documents have been ratified by the leading international scientific associations in this area. We urge that these consensus Whole Grain Initiative definitions be adopted as the basis for definitions used by national regulatory authorities and for health promotion organisations worldwide to use in nutrition education and food labelling.


2012 ◽  
Vol 110 (2) ◽  
pp. 354-362 ◽  
Author(s):  
Niamh F. C. Devlin ◽  
Breige A. McNulty ◽  
Michael J. Gibney ◽  
Frank Thielecke ◽  
Hayley Smith ◽  
...  

A growing body of evidence supports the inclusion of whole grain foods in the diet to help prevent certain chronic diseases. Although much of the research has been conducted in adult cohorts, it is thought that younger populations may also benefit from whole-grain-rich diets. The aim of the present study was to quantify the intake of whole grain in Irish children and teenagers, and assess the major sources of intake. Data used in the present study were from the National Children's Food Survey and the National Teens' Food Survey, which used 7 d food diaries to collect data on habitual food and beverage consumption in representative samples of Irish children and teenagers. Results showed that over 90 % of children (5–12 years) and over 86 % of teenagers (13–17 years) are consumers of whole grain, with mean daily intakes of 18·5 and 23·2 g/d, respectively. Ready-to-eat breakfast cereals made the greatest contribution to whole grain intakes for both children and teenagers (59·3 and 44·3 %), followed by bread (14·4 and 26·5 %), with wheat being the major source of intake, accounting for over 65 % of all whole grains consumed. Whole grain consumers had significantly higher intakes of fibre, P and Mg in comparison with non-consumers of whole grain, even though whole grain intakes in this sample were well below the recommendation of three servings or 48 g/d. The present study characterises, for the first time, the patterns of whole grain consumption in Irish children and teenagers and shows whole grain intake to be low.


2003 ◽  
Vol 62 (1) ◽  
pp. 25-29 ◽  
Author(s):  
Koh-Banerjee Pauline ◽  
Eric B. Rimm

The epidemiological data that directly examine whole grain v. refined grain intake in relation to weight gain are sparse. However, recently reported studies offer insight into the potential role that whole grains may play in body-weight regulation due to the effects that the components of whole grains have on hormonal factors, satiety and satiation. In both clinical trials and observational studies the intake of whole-grain foods was inversely associated with plasma biomarkers of obesity, including insulin, C-peptide and leptin concentrations. Whole-grain foods tend to have low glycaemic index values, resulting in lower postprandial glucose responses and insulin demand. High insulin levels may promote obesity by altering adipose tissue physiology and by enhancing appetite. The fibre content of whole grains may also affect the secretion of gut hormones, independent of glycaemic response, that may act as satiety factors. Future studies may examine whether whole grain intake is directly related to body weight, and whether the associations are primarily driven by components of the grain, including dietary fibre, bran or germ.


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