Over 20 Years of Health Research

BACKGROUND: Postmenopausal women have a high prevalence of hypertension and often develop arterial stiffness thereby increasing cardiovascular disease risk. Although antihypertensive drug therapies exist, increasing numbers of people prefer natural therapies. In vivo studies and a limited number of clinical studies have demonstrated the antihypertensive and vascular-protective effects of blueberries. OBJECTIVE: To examine the effects of daily blueberry consumption for 8 weeks on blood pressure and arterial stiffness in postmenopausal women with pre- and stage 1-hypertension. DESIGN: This was an 8-week, randomized, double-blind, placebo-controlled clinical trial. PARTICIPANTS/SETTING: Forty-eight postmenopausal women with pre- and stage 1-hypertension recruited from the greater Tallahassee, FL, area participated. INTERVENTION: Participants were randomly assigned to receive either 22 g freeze-dried blueberry powder or 22 g control powder. MAIN OUTCOME MEASURES: Resting brachial systolic and diastolic blood pressures were evaluated and arterial stiffness was assessed using carotid-femoral pulse wave velocity and brachial-ankle pulse wave velocity. C-reactive protein, nitric oxide, and superoxide dismutase were measured at baseline, 4 weeks, and 8 weeks. STATISTICAL ANALYSES PERFORMED: Statistical analysis was performed using a split plot model of repeated measures analysis of variance. RESULTS: After 8 weeks, systolic blood pressure and diastolic blood pressure (131+/-17 mm Hg [P<0.05] and 75+/-9 mm Hg [P<0.01], respectively) and brachial-ankle pulse wave velocity (1,401+/-122 cm/second; P<0.01) were significantly lower than baseline levels (138+/-14 mm Hg, 80+/-7 mm Hg, and 1,498+/-179 cm/second, respectively), with significant (P<0.05) groupxtime interactions in the blueberry powder group, whereas there were no changes in the group receiving the control powder. Nitric oxide levels were greater (15.35+/-11.16 mumol/L; P<0.01) in the blueberry powder group at 8 weeks compared with baseline values (9.11+/-7.95 mumol/L), whereas there were no changes in the control group. CONCLUSIONS: Daily blueberry consumption may reduce blood pressure and arterial stiffness, which may be due, in part, to increased nitric oxide production.

BACKGROUND: Nontargeted metabolite profiling allows for concomitant examination of a wide range of metabolite species, elucidating the metabolic alterations caused by dietary interventions. OBJECTIVE: The aim of the current study was to investigate the effects of dietary modifications on the basis of increasing consumption of whole grains, fatty fish, and bilberries on plasma metabolite profiles to identify applicable biomarkers for dietary intake and endogenous metabolism. METHODS: Metabolite profiling analysis was performed on fasting plasma samples collected in a 12-wk parallel-group intervention with 106 participants with features of metabolic syndrome who were randomly assigned to 3 dietary interventions: 1) whole-grain products, fatty fish, and bilberries [healthy diet (HD)]; 2) a whole-grain-enriched diet with the same grain products as in the HD intervention but with no change in fish or berry consumption; and 3) refined-wheat breads and restrictions on fish and berries (control diet). In addition, correlation analyses were conducted with the food intake data to define the food items correlating with the biomarker candidates. RESULTS: Nontargeted metabolite profiling showed marked differences in fasting plasma after the intervention diets compared with the control diet. In both intervention groups, a significant increase was observed in 2 signals identified as glucuronidated alk(en)-ylresorcinols [corrected P value (Pcorr) < 0.05], which correlated strongly with the intake of whole-grain products (r = 0.63, P < 0.001). In addition, the HD intervention increased the signals for furan fatty acids [3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF)], hippuric acid, and various lipid species incorporating polyunsaturated fatty acids (Pcorr < 0.05). In particular, plasma CMPF correlated strongly with the intake of fish (r = 0.47, P < 0.001) but not with intakes of any other foods. CONCLUSIONS: Novel biomarkers of the intake of health-beneficial food items included in the Nordic diet were identified by the metabolite profiling of fasting plasma and confirmed by the correlation analyses with dietary records. The one with the most potential was CMPF, which was shown to be a highly specific biomarker for fatty fish intake. This trial was registered at clinicaltrials.gov as NCT00573781.

BACKGROUND: Nontargeted metabolite profiling allows for concomitant examination of a wide range of metabolite species, elucidating the metabolic alterations caused by dietary interventions. OBJECTIVE: The aim of the current study was to investigate the effects of dietary modifications on the basis of increasing consumption of whole grains, fatty fish, and bilberries on plasma metabolite profiles to identify applicable biomarkers for dietary intake and endogenous metabolism. METHODS: Metabolite profiling analysis was performed on fasting plasma samples collected in a 12-wk parallel-group intervention with 106 participants with features of metabolic syndrome who were randomly assigned to 3 dietary interventions: 1) whole-grain products, fatty fish, and bilberries [healthy diet (HD)]; 2) a whole-grain-enriched diet with the same grain products as in the HD intervention but with no change in fish or berry consumption; and 3) refined-wheat breads and restrictions on fish and berries (control diet). In addition, correlation analyses were conducted with the food intake data to define the food items correlating with the biomarker candidates. RESULTS: Nontargeted metabolite profiling showed marked differences in fasting plasma after the intervention diets compared with the control diet. In both intervention groups, a significant increase was observed in 2 signals identified as glucuronidated alk(en)-ylresorcinols [corrected P value (Pcorr) < 0.05], which correlated strongly with the intake of whole-grain products (r = 0.63, P < 0.001). In addition, the HD intervention increased the signals for furan fatty acids [3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF)], hippuric acid, and various lipid species incorporating polyunsaturated fatty acids (Pcorr < 0.05). In particular, plasma CMPF correlated strongly with the intake of fish (r = 0.47, P < 0.001) but not with intakes of any other foods. CONCLUSIONS: Novel biomarkers of the intake of health-beneficial food items included in the Nordic diet were identified by the metabolite profiling of fasting plasma and confirmed by the correlation analyses with dietary records. The one with the most potential was CMPF, which was shown to be a highly specific biomarker for fatty fish intake. This trial was registered at clinicaltrials.gov as NCT00573781.

Cigarette smoking causes oxidative stress, hypertension and endothelial dysfunction. Polyphenol-rich foods may prevent these conditions. We investigated the effect of a single serving of fresh-frozen blueberry intake on peripheral arterial function and arterial stiffness in young smokers. Sixteen male smokers were recruited for a 3-armed randomized-controlled study with the following experimental conditions: smoking treatment (one cigarette); blueberry treatment (300 g of blueberry) + smoking; control treatment (300 mL of water with sugar) + smoking. Each treatment was separated by one week of wash-out period. The blood pressure, heart rate, peripheral arterial function (reactive hyperemia and Framingham reactive hyperemia), and arterial stiffness (digital augmentation index, digital augmentation index normalized for a heart rate of 75 bpm) were measured before and 20 min after smoking with Endo-PAT2000. Smoking impaired the blood pressure, heart rate and peripheral arterial function, but did not affect the arterial stiffness. Blueberry consumption counteracted the impairment of the reactive hyperemia index induced by smoking (-4.4 +/- 0.8% blueberry treatment vs. -22.0 +/- 1.1% smoking treatment, p < 0.01) and Framingham reactive hyperemia (+28.3 +/- 19.2% blueberry treatment vs. -42.8 +/- 20.0% smoking treatment, p < 0.0001), and the increase of systolic blood pressure (+8.4 +/- 0.02% blueberry treatment vs. +13.1 +/- 0.02% smoking treatment, mmHg, p < 0.05) after cigarette smoking. No effect was observed for arterial stiffness and other vital signs. In conclusion, data obtained suggest a protective role of blueberry on reactive hyperemia, Framingham reactive hyperemia, and systolic blood pressure in subjects exposed to smoke of one cigarette. Future studies are necessary to elucidate the mechanisms involved.

Cigarette smoking causes oxidative stress, hypertension and endothelial dysfunction. Polyphenol-rich foods may prevent these conditions. We investigated the effect of a single serving of fresh-frozen blueberry intake on peripheral arterial function and arterial stiffness in young smokers. Sixteen male smokers were recruited for a 3-armed randomized-controlled study with the following experimental conditions: smoking treatment (one cigarette); blueberry treatment (300 g of blueberry) + smoking; control treatment (300 mL of water with sugar) + smoking. Each treatment was separated by one week of wash-out period. The blood pressure, heart rate, peripheral arterial function (reactive hyperemia and Framingham reactive hyperemia), and arterial stiffness (digital augmentation index, digital augmentation index normalized for a heart rate of 75 bpm) were measured before and 20 min after smoking with Endo-PAT2000. Smoking impaired the blood pressure, heart rate and peripheral arterial function, but did not affect the arterial stiffness. Blueberry consumption counteracted the impairment of the reactive hyperemia index induced by smoking (-4.4 +/- 0.8% blueberry treatment vs. -22.0 +/- 1.1% smoking treatment, p < 0.01) and Framingham reactive hyperemia (+28.3 +/- 19.2% blueberry treatment vs. -42.8 +/- 20.0% smoking treatment, p < 0.0001), and the increase of systolic blood pressure (+8.4 +/- 0.02% blueberry treatment vs. +13.1 +/- 0.02% smoking treatment, mmHg, p < 0.05) after cigarette smoking. No effect was observed for arterial stiffness and other vital signs. In conclusion, data obtained suggest a protective role of blueberry on reactive hyperemia, Framingham reactive hyperemia, and systolic blood pressure in subjects exposed to smoke of one cigarette. Future studies are necessary to elucidate the mechanisms involved.