Effects Of Whole-grain Consumption Research Articles

Comprehensive modulatory effects of whole grain consumption on immune-mediated inflammation in middle-aged and elderly community residents: A real-world randomized controlled trial

Background and aimsWhole grain consumption is widely recognized as a vital component of a balanced diet. Dietary fiber has been well-documented to play a crucial role in these health benefits attributed to whole grain intake. However, population-based evidence directly linking whole grain consumption to anti-inflammatory effects, especially in the context of immune-mediated inflammation, remains limited. We hypothesized that whole grain consumption promotes health by modulating immune-mediated inflammation. Methods and resultsThis study was designed as a real-world, population-based randomized controlled trial. We compared the effects of whole grain versus refined grain consumption on immune-mediated inflammation through staple food substitution, while participants maintained their usual dietary practices. The results demonstrated that whole grain consumption significantly reduced circulating levels of pro-inflammatory cytokines IL-22 and IL-23 compared to refined grain consumption. These reductions were associated with optimized short-chain fatty acid profiles and changes in CD4+ T cell subset distributions. ConclusionsThe findings suggest that the anti-inflammatory effects of whole grain consumption in middle-aged and elderly populations are mediated by targeting specific CD4+ T cell subsets, in addition to modulating both upstream short-chain fatty acid composition and downstream expression of the pro-inflammatory cytokines IL-22 and IL-23.

Estimating effects of whole grain consumption on type 2 diabetes, colorectal cancer and cardiovascular disease: a burden of proof study

BackgroundPrevious studies on whole grain consumption had inconsistent findings and lacked quantitative assessments of evidence quality. Therefore, we aimed to summarize updated findings using the Burden of Proof analysis (BPRF) to investigate the relationship of whole grain consumption on type 2 diabetes (T2D), colorectal cancer (CRC), stroke, and ischemic heart disease (IHD).MethodsWe conducted a literature search in the Medline and Web of Science up to June 12, 2023, to identify related cohort studies and systematic reviews. The mean RR (relative risk) curve and uncertainty intervals (UIs), BPRF function, risk-outcome score (ROS), and the theoretical minimum risk exposure level (TMREL) were estimated to evaluate the level of four risk-outcome pairs.ResultsIn total, 27 prospective cohorts were included in our analysis. Consuming whole grain at the range of TMREL (118.5–148.1 g per day) was associated with lower risks: T2D (declined by 37.3%, 95% UI: 5.8 to 59.5), CRC (declined by 17.3%, 6.5 to 27.7), stroke (declined by 21.8%, 7.3 to 35.1), and IHD (declined by 36.9%, 7.1 to 58.0). For all outcomes except stroke, we observed a non-linear, monotonic decrease as whole grain consumption increased; For stroke, it followed a J-shaped curve (the greatest decline in the risk of stroke at consuming 100 g whole grain for a day). The relationships between whole grain consumption and four diseases are all two-star pairs (ROS: 0.087, 0.068, 0.062, 0.095 for T2D, CRC, stroke, and IHD, respectively).ConclusionConsuming 100 g of whole grains per day offers broad protective benefits. However, exceeding this threshold may diminish the protective effects against stroke. Our findings endorse replacing refined grains with whole grains as the main source of daily carbohydrates.Registry and registry number for systematic reviews or meta-analysesWe have registered our research in PROSPERO, and the identifier of our meta-analyses is CRD42023447345.

The effects of whole grain cereals on tryptophan metabolism and intestinal barrier function: underlying factors of health impact.

This review aims to investigate the relationship between the health impact of whole grains mediated via the interaction with intestinal microbiota and intestinal barrier function with special interest on tryptophan metabolism, focusing on the role of the intestinal microbiota and their impact on barrier function. Consuming various types of whole grains can lead to the growth of different microbiota species, which in turn leads to the production of diverse metabolites, including those derived from tryptophan metabolism, although the impact of whole grains on intestinal microbiota composition results remains inconclusive and vary among different studies. Whole grains can exert an influence on tryptophan metabolism through interactions with the intestinal microbiota, and the presence of fibre in whole grains plays a notable role in establishing this connection. The impact of whole grains on intestinal barrier function is closely related to their effects on the composition and activity of intestinal microbiota, and SCFA and tryptophan metabolites serve as potential links connecting whole grains, intestinal microbiota and the intestinal barrier function. Tryptophan metabolites affect various aspects of the intestinal barrier, such as immune balance, mucus and microbial barrier, tight junction complexes and the differentiation and proliferation of epithelial cells. Despite the encouraging discoveries in this area of research, the evidence regarding the effects of whole grain consumption on intestine-related activity remains limited. Hence, we can conclude that we are just starting to understand the actual complexity of the intestinal factors mediating in part the health impacts of whole grain cereals.

Effects of whole grain intake on glycemic control: A meta-analysis of randomized controlled trials.

Although mounting evidence has suggested an inverse association between the intake of whole grains and glycemic control, findings from randomized controlled trials are still conflicting. The current study was carried out to evaluate the effect of medium/long-term whole grain intake on glycemic control in metabolic syndrome and healthy populations. A literature search was carried out to identify qualified studies up to July 2021. The effects of whole grain consumption on glycemic control were calculated using a fixed effects model. Subgroup analysis was used to study whether grouping factors were important influencing factors of heterogeneity between research results. A total of 32 randomized controlled trials with 2,060 participants were included in the analyses. Whole grain consumption showed a significant inverse regulatory effect on fasting glucose concentration, but no significant effect was found for other glycemic measures, such as fasting insulin, homeostatic model assessment for insulin resistance, glycated hemoglobin and 2-h glucose, in the pooled analysis. Through subgroup analyses, a significant decrease in fasting glucose concentration was observed for studies with a higher whole grain dose, with participants of normal glycemia, and with mixed types of whole grain. Medium-/long-term whole grain intake reduced the fasting glucose concentration compared with similar refined foods. Appropriate intervention dose and accurate population selection might be the key links for whole grain consumption to exert its glycemic control effect.

Front Cover: 5‐Heptadecylresorcinol Protects against Atherosclerosis in Apolipoprotein E‐Deficient Mice by Modulating SIRT3 Signaling: The Possible Beneficial Effects of Whole Grain Consumption

Mol. Nutr. Food Res. 2022, 66, 202101114 DOI: 10.1002/mnfr.202101114 As a biomarker for whole grain dietary intake, 5-heptadecylresorcinol (AR-C17) has been evidenced to alleviate atherosclerosis by improving endothelial cell mitochondrial function via the SIRT3 signaling pathway both in apolipoprotein E-deficient mice and ox-LDL-treated human umbilical vein endothelial cells. This is reported by Jie Liu, Jing Wang, and co-workers in article number 2101114.

5-Heptadecylresorcinol Protects against Atherosclerosis in Apolipoprotein E-Deficient Mice by Modulating SIRT3 Signaling: The Possible Beneficial Effects of Whole Grain Consumption.

Whole grain consumption has been proven to be inversely associated with the risk of cardiovascular diseases. As a biomarker for whole grain dietary intake, 5-heptadecylresorcinol (AR-C17) has attracted increased attention due to its potential health-improving activity. However, the beneficial effect of AR-C17 on atherosclerosis prevention and the underlying mechanism remain unclear. High-fat diet fed apolipoprotein E-deficient (ApoE-/- ) mice are administrated with or without AR-C17 (30 and 150mgkg-1 ) for 16 weeks. Histological staining is performed for plaque analysis. Immunofluorescence, western blot, and seahorse cell analysis are carried out to investigate the action of mechanism of AR-C17. The results indicate that AR-C17 supplementation lowered serum total cholesterol, triglyceride, VLDL-C, and LDL-C levels. Moreover, the atherosclerotic plaques in the aortic root region of mice heart are significantly reduced by AR-C17 intervention compared with ApoE-/- control group. In addition, AR-C17 treatment alleviates endothelial cell damage and apoptosis by improving mitochondrial function via sirtuin3 signaling pathway both in ApoE-/- mice and oxidized-LDL-treated human umbilical vein endothelial cells. AR-C17 may be applied as a promising grain-based dietary bioactive ingredient for atherosclerosis prevention. Meanwhile, as a mitochondrial protective agent, it can offer support for the suggested health claim of whole grain diet.

Role of Whole Grain Consumption in Glycaemic Control of Diabetic Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Background: Observational studies have indicated beneficial effects of whole grain consumption on human health. However, no evidence based on randomized controlled trials has been established. Our objective was to perform a systematic review and meta-analysis of randomized controlled trials to assess the effects of whole grain consumption in glycaemic control of diabetic patients. Methods: A comprehensive search in four databases (Web of Science, Pubmed, Scopus and Cochrane library) was conducted to collect potential articles which measured the roles of whole grain consumption on glycaemic control up to October 2021. Results: A total of 16 eligible trials involving 1068 subjects were identified to evaluate the pooled effect. The overall results indicated that compared with the control group, whole grain intake presented a significantly reduced concentration in fast plasma glucose (WMD = −0.51 mmol/L, 95% CI: −0.73, −0.28; = 88.6%, p < 0.001), a homeostasis model assessment of insulin resistance (WMD = −0.39 μU × mol/L2, 95% CI: −0.73, −0.04; = 58.4%, p = 0.014), and glycosylated haemoglobin (WMD = −0.56%, 95% CI: −0.88, −0.25, = 88.5%, p < 0.001), while no significant difference was observed in fast plasma insulin level between groups (SMD = −0.05, 95% CI: −0.25, 0.14; = 40.7%, p = 0.120). In terms of incremental area under the curve (iAUC), data suggested that whole grain effected a significant decrease in Glucose-iAUC (WMD = −233.09 min × mmol/L, 95% CI: −451.62, −14.57; = 96.1%, p < 0.001) and Insulin-iAUC (SMD = −4.80, 95% CI: −8.36, −1.23; = 89.9%, p = 0.002), although only in a small number of studies. Of note, there is evidence for modest unexplained heterogeneity in the present meta-analysis. Conclusion: Whole grain consumption confers a beneficial effect on glucose metabolism in patients with diabetes. Regrettably, since relevant studies were scarce, we failed to provide confident evidence of whole grain consumption on acute effects including Glucose-iAUC and Insulin-iAUC, which should be addressed in further trials.

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

ObjectivesThe aim of this study was to determine the effects of whole grain consumption on the metabolic profiles of overweight or obese children. MethodsThis 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. ResultsMean (± 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. ConclusionThis 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.

The effects of whole grain intake on anthropometric measures in overweight and obese children: a crossover randomised clinical trial.

Whole-grain foods have been reported to affect body weight and satiety. However, we are aware of no study in this regard among children. The present study aimed to determine the effects of whole grain consumption on anthropometric measures in overweight or obese children. In this randomised crossover clinical trial, forty-four overweight or obese girls participated. After a 2-week run-in period, subjects were randomly assigned to either intervention (n 44) or non-intervention (n 44) groups. Subjects in the intervention group were given a list of whole-grain foods and were asked to obtain half of their grain servings from these foods each day for 6 weeks. Individuals in the non-intervention group were asked not to consume any of these foods. A 4-week washout period was applied. Then, participants were crossed over to the alternate arm. The measurements were done before and after each phase. Mean age, weight and BMI of participants were 11·2 (sd 1·49) years, 51·2 (sd 10·2) kg and 23·5 (sd 2·5) kg/m2, respectively. Despite the slight reduction in weight and BMI, there were no significant differences in changes in these anthropometric measures. We found a significant effect of whole grain intake on waist circumference (-2·7 v. 0·3 cm, P = 0·04). No significant changes in hip circumference were observed. Changes in the prevalence of overweight, obesity and abdominal obesity were not significantly different. This study indicated a beneficial effect of whole-grain foods on waist circumference in overweight children; however, these foods did not influence weight and BMI.

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.

Effect of whole-grain consumption on changes in fecal microbiota: a review of human intervention trials.

Whole-grain (WG) consumption is known to have beneficial effects on human health. However, the influence of WGs on the microbiota is not well understood. To evaluate how WG intake modulates the gut microbiota composition, a literature review of human intervention studies was conducted. Whole grain, whether a mixed WG food or diet (n = 5) or specific WG intervention (WG wheat [n = 5], barley [n = 2], rye [n = 2] or rice, corn, or oats [n = 1 for each]), generally modified microbiota composition but did so inconsistently across measurements of microbial diversity and taxa. Interventions used both parallel and crossover designs and varied from single product substitutions to fully controlled diets with WG exposures of 3-12 weeks. The effect of amount of WG was difficult to capture due to variable reporting of WG. Methods used to measure microbiota varied in ability to resolve changes at different taxonomic levels, and comparisons of interventions using similar methods was lacking. Because many dietary components besides WGs alter gut microbiota, further research is needed, particularly in linking microbiota changes to health outcomes, and study design recommendations for future research on WGs and microbiota are warranted.

Diets enriched with whole grains reduce premenstrual syndrome scores in nurses: an open-label parallel randomised controlled trial.

Although previous studies have demonstrated the beneficial effects of some components of whole grains on premenstrual syndrome (PMS), our literature review shows that no clinical trial has studied the effect of whole grain consumption on PMS so far. Therefore, the present study was designed to study the effect of diets rich in whole grains on PMS among nurses. This study is a parallel controlled clinical trial with a 3-month intervention period in which, after following two menstrual cycles among nurses, 100 nurses diagnosed with PMS were randomly divided into two groups of intervention and control, with fifty individuals in each. Those in the intervention group replaced at least four servings of refined grains in their daily diets with whole grains. To supply four servings, 120 g of bread made with whole flour was given to the intervention group on a daily basis. Those in the control group, however, continued their regular daily consumption of grains. The two groups were compared regarding PMS symptoms after adjusting the confounding variables. The repeated measurement test showed that the interaction between the time factor and the experimental group on the mean score of PMS symptoms was significant. That is, the intervention group showed a significant decrease in the general, mood, physical and behavioural symptoms of PMS compared with the controls (P&lt;0·001, P=0·01, P&lt;0·001 and P=0·003, respectively). Therefore, daily consumption of whole grains in place of refined grains can contribute to improvement in PMS symptoms. Further studies are needed to confirm our findings.

Gastrointestinal Microbial Changes Following Whole Grain Barley and Oat Consumption in Healthy Men and Women

BackgroundWhole grain fiber consumption is a promising approach to positively alter the human gastrointestinal (GI) microbiome. The Dietary Guidelines for Americans recommends half of all grain servings be consumed as whole grains to minimize chronic disease risk. However, little is known about the effects of whole grain barley and oat consumption in their whole food forms on GI microbial profiles in healthy individuals.ObjectiveWe aimed to assess the impact of whole grain barley and oat consumption on the GI microbiota in healthy men and women and determine whether effects of whole grain consumption on the GI microbiota are associated with metabolic and immunological improvements.MethodsA 6‐week randomized, double‐blinded, parallel‐arm, controlled‐feeding intervention was undertaken in healthy adults (n=68) fed at weight maintenance. Male and female participants were randomly assigned to 1 of 3 treatments: 1) a control diet containing 0.8 daily servings of whole grain/1800 kcal, 2) a diet containing 4.4 daily servings of whole grain barley/1800 kcal or 3) a diet containing 4.4 daily servings of whole grain oats/1800 kcal. Blood, urine, and fecal samples were collected at baseline and at the end of the intervention period for metabolic, immunologic, and microbial analyses. Bacterial, fungal, and archaeal sequences were generated using an Illumina MiSeq and analyzed with QIIME 1.8. Data were analyzed using SAS 9.4.ResultsPrior to treatments, associations between bacterial taxa and host metabolism were observed. The Bacteriodes:Firmicutes ratio was negatively correlated with BMI (r=−0.31, p=0.009). The abundance of Bifidobacterium was negatively correlated with age (r=−0.40, p=0.0008). Alternatively, Collinsella was positively correlated with age (r=0.26, p=0.03), LDL cholesterol (r=0.21, p=0.09), and triglycerides (r=0.23, p=0.06). Microbial community structure was affected by whole grain barley and oat consumption. Total species richness was higher in participants consuming oats compared with control (p=0.01). Principal coordinates analysis (PCoA) of UniFrac distances between samples based on their 97% OTU composition and abundances indicated that the microbiota of participants within a treatment were more similar than between treatments (p=0.03).ConclusionsOur findings are congruent with previous research demonstrating associations between the GI microbiota, weight status, age, and serum lipids. Ecological analyses revealed that whole grain barley and oats induced changes in the microbial community structure of the Gl microbiota. Additional study is ongoing to delineate the microbial taxa driving these shifts and the interrelationships among changes in the GI microbiota and metabolic improvements.Support or Funding InformationThis study was funded by USDA and the Kellogg Company.

Evaluation of genetic variation and grain quality of old bread wheat varieties introduced in north-western Italian environments

The increasing consumers’ request for new speciality wheat derivatives and the possible widening of marketing opportunities is giving to both landraces and old varieties, new chance of on farm survival providing a low cost way to safeguard these important genetic resources. A farmer’s consortium acting in north-western Italy, is attempting the introduction of some old bread wheat landraces in marginal environments of Piedmont and Liguria regions. The reason of this attempt is the local market demand of old bread varieties suitable for the preparation of traditional cakes and biscuits. Three Italian bread wheat landraces, a mixture of durum and bread wheat landraces and three modern varieties were evaluated. The entries were cropped in Val Borbera and Val d’Aveto (Piedmont and Liguria region, respectively) in the same growing season (2009–2010). The high variation of gliadin profile detected within the landraces indicates that all have retained the genetic heterogeneity typical of the old wheat landraces. In consequence of the health-promoting effects of whole grain consumption, eleven nutritional and technological traits of whole flours were investigated. The analysis of collected data revealed appreciable differences among the flours obtained from the landraces and the modern varieties. These differences can be mainly attributed to the intensive breeding carried out on bread wheat in the last century. The results of this study suggest that the old bread wheat landraces could have good chance of survive on farm when their characteristics fulfil the requirements of local communities.

Effect of Whole Grains on Markers of Systemic Inflammation

Reducing subclinical systemic inflammation has been suggested as one potential mechanism to explain the favorable association between whole grain consumption and reduced risk for cardiovascular disease, diabetes and certain cancers. The objective of this study was to review the evidence derived from both epidemiologic and interventions on the effects of whole grain consumption on markers of systemic inflammation. Epidemiological studies provide reasonable support for an association between diets high in whole grains and lower CRP levels. After adjusting for other dietary factors each serving of whole grains is estimated to reduce CRP levels by approximately 7%. This translates to ~20% decline in CRP levels if one achieves the recommended 3 servings/d of whole grains. In contrast to epidemiology studies, intervention studies did not demonstrate a clear effect of increased whole grain consumption on CRP or other markers of inflammation. Issues related to the extent of dietary control, population selection and types of whole grains may underlie these discrepant findings. Based on the existing evidence, it appears that ~40% of the improvement in CRP levels associated with increased whole grain consumption may potentially be through their favorable effect on adiposity and insulin sensitivity. Additional carefully controlled intervention studies are needed to confirm effects of whole grains on subclinical systemic inflammation.

Whole grain consumption does not slow diabetic progression in GK rats

Whole grain consumption is inversely associated with risk of type II diabetes epidemiologically. The aim of this study was to study the effect of whole grain consumption on diabetic control and progression in an animal model of type II diabetes, the Goto‐Kakisaki (GK) rat. GK rats were fed either a whole grain‐free control diet or a whole grain‐containing diet for 5 months. Whole grain diets contained 65% whole grain flours of either wheat, barley, oat, or corn. After two months, fasting plasma glucose concentration was significantly lower with the wheat, barley, or oat diets compared to the control diet. However, glycated hemoglobin was significantly greater in the wheat group compared to other groups. At 5 months, whole grain diets did not improve glycemic control. Fasting plasma insulin and C‐Peptide levels were decreased from month 2 to month 5 indicating diabetic progression. Insulin resistance, determined by the homeostasis model assessment, was not significantly different among groups at either 2 or 5 months. However, there was a trend for improvement of insulin resistance with the barley and oat diets at 2 months (P=0.06). There were no significant differences in the total pancreatic β‐cell mass among groups. These results offer little support for improvement of diabetic control and delayed progression with consumption of whole grains. (Supported by the General Mills Bell Inst. of Health and Nutrition)Grant Funding SourceGeneral Mills Bell Inst. of Health and Nutrition

The effect of whole grain consumption (WG) on diet quality and Healthy Eating Index (HEI) scores in children aged 1 to 18 years: Results from NHANES 1999‐2004

The objective of this study was to examine the effect of WG consumption on diet quality &amp; nutrient intake in children: 2‐5 years [y] (n=2,278), 6‐12 y (n=3,868), &amp; 13‐18 y (n=4,931) using a secondary analysis of NHANES 1999‐2004 data. Age groups were divided into four WG consumption groups: &gt;0 to &lt;0.6, &gt;0.6 to &lt;1.5, &gt;1.5 to &lt;3.0, &amp; &gt;3.0 servings/day. Nutrient intakes &amp; HEI scores were calculated. The mean number of servings of WG consumed was 0.45, 0.59, &amp; 0.63 for children 2‐5 y, 6‐12 y, &amp; 13‐18 y, respectively. In 2‐5 y, HEI, &amp; intake of energy, fiber, vitamins A, C, B1, B6, folate, magnesium, phosphorus, &amp; iron increased with increasing consumption of WG; whereas, protein, added sugars, total fat, saturated fat (SFA), monounsaturated fat (MUFA), &amp; cholesterol decreased. In 6‐12 y, HEI, &amp; intake of energy, fiber, vitamins A, C, B6, folate, magnesium, potassium, phosphorus, iron, &amp; sodium increased with increasing consumption of WG; intake of protein, SFA, MUFA, polyunsaturated fat, &amp; cholesterol decreased. In 13‐18 y, HEI &amp; intake of energy, fiber, vitamins A, E, B1, B2, B6, folate, magnesium, phosphorus, &amp; iron increased with increasing consumption of WG; intake of protein, total fat, SFA, MUFA, &amp; cholesterol decreased. Consumption of WG was low; diet quality &amp; nutrient intake in children significantly improved with increasing consumption of WG. Supported by USDA and Kellogg's Corporate Citizenship Fund.

Whole grain consumption reduces insulin demand, lipid peroxidation and plasma homocysteine concentrations in patients with coronary artery disease

Background:Although current dietary guidelines recommend to increase the consumption of whole grain, these recommendations are mainly derived from the belief that replacing fats with carbohydrate may reduce risk of coronary artery disease (CAD by improving serum lipids. Our objective was to evaluate whether the isocalorical replacement of refined rice with whole grain reduce CAD risk factors such as insulin demand and lipid peroxidation in CAD patients. Methods:Thirty-eight male patients with CAD were provided with 70 g powder of whole grain (220 kcal for 16 weeks, replacing cooked refined rice as a carbohydrate source of breakfast. An oral glucose tolerance test (OGTT was performed in all subjects to determine the effect of whole grain consumption on serum concentrations of insulin and glucose in CAD patients with different degree of glucose tolerance. Results:With the substitution of whole grain for refined rice, serum glucose concentrations decreased by 24% without altering body weight and energy intake. Estimates of daily fiber and vitamin E intakes increased by 24% and 50%, respectively. Whole grain consumption in CAD patients without diabetes decreased fasting glucose (22% and the area under the curve (AUC for insulin (26% and glucose (19% during an OGTT. CAD patients with diabetes also showed reductions in fasting glucose (27% and AUC for glucose (25% during the OGTT, compared with baseline values. Whole grain consumption reduced plasma malon- dialdehyde and homocysteine and urinary 8-epi-prostaglandin F2α concentrations by about 30%. Lipid-corrected concentrations of α-carotene, retinol, α- and γ-tocopherol and lycopene increased by 22-46%, compared with baseline values. Whole grain consumption decreased the percentage composition of ω6 fatty acids of serum phospholipid increased by 14%. Conclusion:The replacement of refined rice with whole grain as a carbohydrate source of a meal showed significant beneficial effects on glucose, insulin and homocysteine concentrations and lipid peroxidation in CAD patients. These effects are likely to substantially reduce the risk factors of CAD and diabetes in CAD patients. (Korean Circulation J 2000;30(6 :693-701