Dietary flavonoid intake and incidence of erectile dysfunction.

BACKGROUND: The predominant etiology for erectile dysfunction (ED) is vascular, but limited data are available on the role of diet. A higher intake of several flavonoids reduces diabetes and cardiovascular disease risk, but no studies have examined associations between flavonoids and erectile function. OBJECTIVE: This study examined the relation between habitual flavonoid subclass intakes and incidence of ED. DESIGN: We conducted a prospective study among 25,096 men from the Health Professionals Follow-Up Study. Total flavonoid and subclass intakes were calculated from food-frequency questionnaires collected every 4 y. Participants rated their erectile function in 2000 (with historical reporting from 1986) and again in 2004 and 2008. RESULTS: During 10 y of follow-up, 35.6% reported incident ED. After multivariate adjustment, including classic cardiovascular disease risk factors, several subclasses were associated with reduced ED incidence, specifically flavones (RR = 0.91; 95% CI: 0.85, 0.97; P-trend = 0.006), flavanones (RR = 0.89; 95% CI: 0.83, 0.95; P-trend = 0.0009), and anthocyanins (RR = 0.91; 95% CI: 0.85, 0.98; P-trend = 0.002) comparing extreme intakes. The results remained statistically significant after additional adjustment for a composite dietary intake score. In analyses stratified by age, a higher intake of flavanones, anthocyanins, and flavones was significantly associated with a reduction in risk of ED only in men <70 y old and not older men (11-16% reduction in risk; P-interaction = 0.002, 0.03, and 0.007 for flavones, flavanones, and anthocyanins, respectively). In food-based analysis, higher total intake of fruit, a major source of anthocyanins and flavanones, was associated with a 14% reduction in risk of ED (RR = 0.86; 95% CI: 0.79, 0.92; P = 0.002). CONCLUSIONS: These data suggest that a higher habitual intake of specific flavonoid-rich foods is associated with reduced ED incidence. Intervention trials are needed to further examine the impact of increasing intakes of commonly consumed flavonoid-rich foods on men's health.

High anthocyanin intake is associated with a reduced risk of myocardial infarction in young and middle-aged women.

BACKGROUND: Our current knowledge of modifiable risk factors to prevent myocardial infarction (MI) in young and middle-aged women is limited, and the impact of diet is largely unknown. Dietary flavonoids exert potential beneficial effects on endothelial function in short-term trials; however, the relationship between habitual intake and risk of MI in women is unknown. METHODS AND RESULTS: We followed up 93 600 women 25 to 42 years of age from the Nurses' Health Study (NHS) II who were healthy at baseline (1989) to examine the relationship between anthocyanins and other flavonoids and the risk of MI. Intake of flavonoid subclasses was calculated from validated food-frequency questionnaires collected every 4 years using an updated and extended US Department of Agriculture database. During 18 years of follow-up, 405 cases of MI were reported. An inverse association between higher intake of anthocyanins and risk of MI was observed (hazard ratio, 0.68; 95% confidence interval, 0.49-0.96; P=0.03, highest versus lowest quintiles) after multivariate adjustment. The addition of intermediate conditions, including history of hypertension, did not significantly attenuate the relationship (hazard ratio, 0.70; 95% confidence interval, 0.50-0.97; P=0.03). Combined intake of 2 anthocyanin-rich foods, blueberries and strawberries, tended to be associated with a decreased risk of MI (hazard ratio, 0.66; 95% confidence interval, 0.40-1.08) in a comparison of those consuming >3 servings a week and those with lower intake. Intakes of other flavonoid subclasses were not significantly associated with MI risk. CONCLUSIONS: A high intake of anthocyanins may reduce MI risk in predominantly young women. Intervention trials are needed to further examine the health impact of increasing intakes of commonly consumed anthocyanin-rich foods.

Dietary insulin index and insulin load in relation to biomarkers of glycemic control, plasma lipids, and inflammation markers.

BACKGROUND: Dietary glycemic index and load are widely used to estimate the effect of carbohydrate-containing foods on postprandial blood glucose concentrations and as surrogates for insulin response. The food insulin index (II) directly quantifies the postprandial insulin secretion of a food and takes into account foods with a low or no carbohydrate content. OBJECTIVE: We investigated the average dietary II and insulin load (IL) in relation to biomarkers of glycemic control, plasma lipids, and inflammation markers. DESIGN: In a cross-sectional setting and with the use of data from the Nurses' Health Study and the Health Professionals Follow-Up Study, we measured plasma concentrations of C-peptide, glycated hemoglobin (Hb A(1c)), HDL cholesterol, LDL cholesterol, triglycerides, C-reactive protein (CRP), and interleukin-6 (IL-6) in fasting blood samples of 4002 healthy men and women. The dietary II and IL were assessed from food-frequency questionnaires by using directly analyzed or published food II data. RESULTS: After multivariate adjustment, participants in the highest quintile of II had 26% higher triglyceride concentrations than did participants in the lowest quintile of II (P for trend < 0.0001). This association was strongest in obese [body mass index (in kg/m(2)) ≥30] participants (difference between highest and lowest quintiles in the II: 72%; P for trend = 0.01). Dietary II was inversely associated with HDL cholesterol in obese participants (difference: -18%; P for trend = 0.03). Similar associations were seen for the IL. Dietary II and IL were not significantly associated with plasma C-peptide, Hb A(1c), LDL cholesterol, CRP, or IL-6. CONCLUSION: Dietary II and IL were not associated with fasting biomarkers of glycemic control but may be physiologically relevant to plasma lipids, especially in obese individuals.

Habitual intake of flavonoid subclasses and incident hypertension in adults.

BACKGROUND: Dietary flavonoids have beneficial effects on blood pressure in intervention settings, but there is limited information on habitual intake and risk of hypertension in population-based studies. OBJECTIVE: We examined the association between habitual flavonoid intake and incident hypertension in a prospective study in men and women. DESIGN: A total of 87,242 women from the Nurses' Health Study (NHS) II, 46,672 women from the NHS I, and 23,043 men from the Health Professionals Follow-Up Study (HPFS) participated in the study. Total flavonoid and subclass intakes were calculated from semiquantitative food-frequency questionnaires collected every 4 y by using an updated and extended US Department of Agriculture database. RESULTS: During 14 y of follow-up, 29,018 cases of hypertension in women and 5629 cases of hypertension in men were reported. In pooled multivariate-adjusted analyses, participants in the highest quintile of anthocyanin intake (predominantly from blueberries and strawberries) had an 8% reduction in risk of hypertension [relative risk (RR): 0.92; 95% CI: 0.86, 0.98; P < 0.03] compared with that for participants in the lowest quintile of anthocyanin intake; the risk reduction was 12% (RR: 0.88; 95% CI: 0.84, 0.93; P < 0.001) in participants ≤60 y of age and 0.96 (0.91, 1.02) in participants >60 y of age (P for age interaction = 0.02). Although intakes of other subclasses were not associated with hypertension, pooled analyses for individual compounds suggested a 5% (95% CI: 0.91, 0.99; P = 0.005) reduction in risk for the highest compared with the lowest quintiles of intake of the flavone apigenin. In participants ≤60 y of age, a 6% (95% CI: 0.88, 0.97; P = 0.002) reduction in risk was observed for the flavan-3-ol catechin when the highest and the lowest quintiles were compared. CONCLUSIONS: Anthocyanins and some flavone and flavan-3-ol compounds may contribute to the prevention of hypertension. These vasodilatory properties may result from specific structural similarities (including the B-ring hydroxylation and methyoxylation pattern).

Relation of food cost to healthfulness of diet among US women.

BACKGROUND: Few studies have evaluated the cost of a diet that may prevent cardiovascular disease. High scores on the Alternative Healthy Eating Index (AHEI) have been associated with lower rates of cardiovascular disease. OBJECTIVE: We sought to evaluate the cost of a dietary pattern that may prevent cardiovascular disease among women residing in the United States. DESIGN: By using food-cost data from the US Department of Agriculture, we explored relations between spending on food and AHEI scores among 78,191 participants in the Nurses' Health Study. By using linear regression, we estimated the change in AHEI score (range: 2.5-87.5) for a $1 increase in spending on various food groups. RESULTS: Study participants in the highest energy-adjusted spending quintile spent 124% as much money each day as those in the lowest quintile. The difference in AHEI scores (10th-90th percentile) between all study participants was 30 index points (Spearman's correlation coefficient between total spending and AHEI = 0.44). The difference in AHEI scores (10th-90th percentile) within each quintile of spending ranged from 25 to 29 index points. Greater spending on nuts, soy and beans, and whole grains was associated with a higher AHEI score. Greater spending on red and processed meats and high-fat dairy was associated with a lower AHEI score. CONCLUSIONS: Although spending more money was associated with a healthier diet, large improvements in diet may be achieved without increased spending. The purchase of plant-based foods may offer the best investment for dietary health.

Whole grains and incident hypertension in men.

BACKGROUND: Prospective data on the relation between whole grain intake and incident hypertension in men are limited, and no previous studies have quantitatively estimated total grams of whole grains in relation to risk of hypertension. OBJECTIVE: The purpose of this study was to estimate the association of whole-grain intake (g/d) and risk of incident hypertension in a large prospective cohort of men. DESIGN: The Health Professionals Follow-Up Study is a prospective cohort consisting of 51,529 male health professionals ranging in age from 40 to 75 y at enrollment in 1986. Baseline and updated measurement of whole-grain intake as well as important covariates were measured, and 31,684 participants without known hypertension, cancer, stroke, or coronary heart disease were followed prospectively for 18 y through 2004 for onset of hypertension. RESULTS: A total of 9227 cases of incident hypertension were reported over the 18 y of follow-up. In multivariate-adjusted analyses, whole-grain intake was inversely associated with risk of hypertension, with a relative risk (RR) of 0.81 (95% CI: 0.75-0.87) in the highest compared with the lowest quintile (P for trend < 0.0001). In the multivariate model, total bran was inversely associated with hypertension, with a relative risk (RR) of 0.85 (95% CI: 0.78, 0.92) in the highest compared with the lowest quintile (P for trend: 0.002). CONCLUSIONS: In summary, we found an independent inverse association between intake of whole grains and incident hypertension in men. Bran may play an important role in this association. These findings have implications for future dietary guidelines and prevention of hypertension.

Whole grain, bran, and germ intake and risk of type 2 diabetes: a prospective cohort study and systematic review.

BACKGROUND: Control of body weight by balancing energy intake and energy expenditure is of major importance for the prevention of type 2 diabetes, but the role of specific dietary factors in the etiology of type 2 diabetes is less well established. We evaluated intakes of whole grain, bran, and germ in relation to risk of type 2 diabetes in prospective cohort studies. METHODS AND FINDINGS: We followed 161,737 US women of the Nurses' Health Studies (NHSs) I and II, without history of diabetes, cardiovascular disease, or cancer at baseline. The age at baseline was 37-65 y for NHSI and 26-46 y for NHSII. Dietary intakes and potential confounders were assessed with regularly administered questionnaires. We documented 6,486 cases of type 2 diabetes during 12-18 y of follow-up. Other prospective cohort studies on whole grain intake and risk of type 2 diabetes were identified in searches of MEDLINE and EMBASE up to January 2007, and data were independently extracted by two reviewers. The median whole grain intake in the lowest and highest quintile of intake was, respectively, 3.7 and 31.2 g/d for NHSI and 6.2 and 39.9 g/d for NHSII. After adjustment for potential confounders, the relative risks (RRs) for the highest as compared with the lowest quintile of whole grain intake was 0.63 (95% confidence interval [CI] 0.57-0.69) for NHSI and 0.68 (95% CI 0.57-0.81) for NHSII (both: p-value, test for trend <0.001). After further adjustment for body mass index (BMI), these RRs were 0.75 (95% CI 0.68-0.83; p-value, test for trend <0.001) and 0.86 (95% CI 0.72-1.02; p-value, test for trend 0.03) respectively. Associations for bran intake were similar to those for total whole grain intake, whereas no significant association was observed for germ intake after adjustment for bran. Based on pooled data for six cohort studies including 286,125 participants and 10,944 cases of type 2 diabetes, a two-serving-per-day increment in whole grain consumption was associated with a 21% (95% CI 13%-28%) decrease in risk of type 2 diabetes after adjustment for potential confounders and BMI. CONCLUSIONS: Whole grain intake is inversely associated with risk of type 2 diabetes, and this association is stronger for bran than for germ. Findings from prospective cohort studies consistently support increasing whole grain consumption for the prevention of type 2 diabetes.

Whole-grain and fiber intakes and periodontitis risk in men.

BACKGROUND: Diabetes and hyperglycemia increase periodontitis risk, severity, and extent. Increased whole-grain and fiber intakes are associated with improved insulin sensitivity and may therefore affect periodontitis risk. OBJECTIVE: The objective was to examine the associations between whole-grain and fiber intakes and periodontitis risk. DESIGN: We prospectively followed 34,160 male US health professionals aged 40-75 y at the outset. We updated medical and lifestyle information biennially with questionnaires and diet every 4 y by using a validated food-frequency questionnaire. We excluded men reporting periodontitis, myocardial infarction, stroke, and hypercholesterolemia before 1986 and those with incomplete dietary data. All diabetics were excluded. Periodontitis was determined by a report of professionally diagnosed disease and validated by a diagnosis of periodontitis by a periodontist from a blinded review of radiographs. RESULTS: Men in the highest quintile of whole-grain intake were 23% less likely to get periodontitis than were those in the lowest quintile (multivariate RR: 0.77; 95% CI: 0.66, 0.89; P for trend < 0.001) after adjustment for age, smoking, body mass index, alcohol intake, physical activity, and total energy intake. Periodontitis was not associated with refined-grain intake (multivariate RR comparing extreme quintiles of intake: 1.04; 95% CI: 0.89, 1.23; P for trend = 0.37). Cereal fiber was inversely related to periodontitis risk (multivariate RR comparing extreme quintiles of intake: 0.85; 95% CI: 0.73, 0.99; P for trend = 0.03), but the association was not significant after adjustment for whole-grain intake. CONCLUSION: Increasing whole grain in the diet without increasing total energy intake may reduce periodontitis risk.

Whole grains, bran, and germ in relation to homocysteine and markers of glycemic control, lipids, and inflammation 1.

BACKGROUND: Intake of whole grains is inversely associated with risk of diabetes and ischemic heart disease in observational studies. The lower risk associated with high whole-grain intakes may be mediated through improvements in glycemic control, lipid profiles, or reduced inflammation. OBJECTIVE: The aim was to examine whether the intake of whole grains, bran, and germ is related to homocysteine, plasma markers of glycemic control (fasting insulin, hemoglobin A1c, C-peptide, and leptin), lipids (total cholesterol, triacylglycerol, HDL cholesterol, and LDL cholesterol), and inflammation (C-reactive protein, fibrinogen, and interleukin 6). DESIGN: This was a cross-sectional study of the relations of whole grains, bran, and germ intakes with homocysteine and markers of glycemic control, lipids, and inflammation in 938 healthy men and women. RESULTS: Whole-grain intake was inversely associated with homocysteine and markers of glycemic control. Compared with participants in the bottom quintile of whole-grain intake, participants in the highest quintile had 17%, 14%, 14%, and 11% lower concentrations of homocysteine (P < 0.01), insulin (P = 0.12), C-peptide (P = 0.03), and leptin (P = 0.03), respectively. Inverse associations were also observed with total cholesterol (P = 0.02), HDL cholesterol (P = 0.05), and LDL cholesterol (P = 0.10). Whole-grain intake was not associated with the markers of inflammation. Whole-grain intake was most strongly inversely associated with markers of glycemic control in this population. CONCLUSION: The results suggest a lower risk of diabetes and heart disease in persons who consume diets high in whole grains.

Whole-grain, bran, and cereal fiber intakes and markers of systemic inflammation in diabetic women.

OBJECTIVE: To evaluate the dietary predictors for the markers of systemic inflammation and endothelial dysfunction in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: We examined whether intakes of whole grains and dietary fiber were associated with inflammatory indicators among 902 diabetic women in the Nurses' Health Study. RESULTS: After adjustment for age, BMI, lifestyle, and dietary covariates, intakes of whole grains and bran were both associated with significantly decreasing trends of C-reactive protein (CRP) (P for trend = 0.03 and 0.007, respectively) and tumor necrosis factor-alpha receptor 2 (TNF-R2) (P for trend = 0.017 and 0.06). High intake of cereal fiber was also inversely associated with the lower levels of CRP (P for trend = 0.03) and TNF-R2 (P for trend = 0.01). The concentrations of CRP and TNF-R2 were 18 and 8% lower in the highest quintile of cereal fiber as compared with the lowest quintile. Dietary glycemic index was positively associated with CRP (P for trend = 0.04) and TNF-R2 (P for trend = 0.0008) levels. The concentrations of CRP and TNF-R2 were 32 and 11% higher, respectively, in the highest quintile of dietary glycemic index as compared with the lowest quintile. CONCLUSIONS: Our data indicate that whole grains and a low-glycemic index diet may reduce systemic inflammation among women with type 2 diabetes.

Intakes of whole grains, bran, and germ and the risk of coronary heart disease in men.

BACKGROUND: Previous studies have suggested that a daily intake of 3 servings of whole-grain foods is associated with a reduced risk of coronary heart disease (CHD). However, methods for the assessment of whole-grain intake differ. Furthermore, any additional effects of added bran and germ, which are components of whole grains, have not been reported. OBJECTIVE: The objective was to evaluate the association of whole-grain, bran, and germ intakes (with the use of new quantitative measures) with the incidence of CHD. DESIGN: This was a prospective cohort study of 42,850 male health professionals aged 40-75 y at baseline in 1986 who were free from cardiovascular disease, cancer, and diabetes. Daily whole-grain, bran, and germ intakes were derived in grams per day from a detailed semiquantitative dietary questionnaire. RESULTS: During 14 y of follow-up, we documented 1818 incident cases of CHD. After cardiovascular disease risk factors and the intakes of bran and germ added to foods were controlled for, the hazard ratio of CHD between extreme quintiles of whole-grain intake was 0.82 (95% CI: 0.70, 0.96; P for trend=0.01). The hazard ratio of CHD in men with the highest intake of added bran was 0.70 (95% CI: 0.60, 0.82) compared with men with no intake of added bran (P for trend < or = 0.001). Added germ was not associated with CHD risk. CONCLUSION: This study supports the reported beneficial association of whole-grain intake with CHD and suggests that the bran component of whole grains could be a key factor in this relation.

Changes in whole-grain, bran, and cereal fiber consumption in relation to 8-y weight gain among men.

BACKGROUND: Epidemiologic studies that directly examine changes in whole-grain consumption in relation to weight gain are sparse, and characterization of this association has been obscured by methodologic inconsistencies in the assessment of whole grains. OBJECTIVE: We aimed to ascertain the associations between changes in new quantitative estimates of whole-grain intake and 8-y weight gain among US men. DESIGN: The study was conducted in a prospective cohort of 27 082 men aged 40-75 y at baseline in 1986. Data on lifestyle factors were obtained periodically by using self-reported questionnaires, and participants measured and reported their body weight in 1986 and 1994. RESULTS: In multivariate analyses, an increase in whole-grain intake was inversely associated with long-term weight gain (P for trend < 0.0001). A dose-response relation was observed, and for every 40-g/d increment in whole-grain intake from all foods, weight gain was reduced by 0.49 kg. Bran that was added to the diet or obtained from fortified-grain foods further reduced the risk of weight gain (P for trend = 0.01), and, for every 20 g/d increase in intake, weight gain was reduced by 0.36 kg. Changes in cereal and fruit fiber were inversely related to weight gain. No associations were observed between changes in refined-grain or added germ consumption and body weight. CONCLUSIONS: The increased consumption of whole grains was inversely related to weight gain, and the associations persisted after changes in added bran or fiber intakes were accounted for. This suggests that additional components in whole grains may contribute to favorable metabolic alterations that may reduce long-term weight gain.