The role of dietary nitrate and the oral microbiome on blood pressure and vascular tone.

There is increasing evidence for the health benefits of dietary nitrates including lowering blood pressure and enhancing cardiovascular health. Although commensal oral bacteria play an important role in converting dietary nitrate to nitrite, very little is known about the potential role of these bacteria in blood pressure regulation and maintenance of vascular tone. The main purpose of this review is to present the current evidence on the involvement of the oral microbiome in mediating the beneficial effects of dietary nitrate on vascular function and to identify sources of inter-individual differences in bacterial composition. A systematic approach was used to identify the relevant articles published on PubMed and Web of Science in English from January 1950 until September 2019 examining the effects of dietary nitrate on oral microbiome composition and association with blood pressure and vascular tone. To date, only a limited number of studies have been conducted, with nine in human subjects and three in animals focusing mainly on blood pressure. In general, elimination of oral bacteria with use of a chlorhexidine-based antiseptic mouthwash reduced the conversion of nitrate to nitrite and was accompanied in some studies by an increase in blood pressure in normotensive subjects. In conclusion, our findings suggest that oral bacteria may play an important role in mediating the beneficial effects of nitrate-rich foods on blood pressure. Further human intervention studies assessing the potential effects of dietary nitrate on oral bacteria composition and relationship to real-time measures of vascular function are needed, particularly in individuals with hypertension and those at risk of developing CVD.

Diets containing the highest levels of dairy products are associated with greater eutrophication potential but higher nutrient intakes and lower financial cost in the United Kingdom.

PURPOSE: Previously, the nutritional contribution, environmental and financial costs of dairy products have been examined independently. Our aim was to determine the nutritional adequacy, financial cost and environmental impact of UK diets according to dairy content. METHODS: In this cross-sectional study of adults (19-64 years) from the UK National Diet and Nutrition Survey years 1-4 (n = 1655), dietary intakes assessed from 4-day estimated food diaries were organized into quartiles (Q) total grams of dairy (milk, cheese, yogurt, dairy desserts) and analyzed using ANCOVA controlling for age, sex and energy intake with Bonferroni post hoc test for nutritional adequacy, Alternative Healthy Eating Index (AHEI-2010), environmental impact [greenhouse gas emissions (GHGE), eutrophication and acidification potentials], financial cost, markers of health and cardio-metabolic diseases. RESULTS: Nutritional adequacy, particularly for protein, calcium and iodine (+ 18 g, + 533 mg, + 95 g, respectively, all P < 0.0001) and AHEI-2010 (P < 0.0001) were significantly higher and systolic BP (- 2 mmHg, P = 0.019) was significantly lower for the higher-dairy diets (Q4, 274-1429 g/day dairy), compared with diets containing lower dairy (Q1, 0-96 g/day dairy). Diets in Q4 had lower financial cost (- 19%, P < 0.0001) and the greatest eutrophication potential, compared with Q1 (+ 29%, P < 0.0001). Yet the environmental (GHGE) and financial costs per unit nutrient (riboflavin, zinc, iodine, magnesium, calcium, potassium) were lower in Q4 than Q1 (all P < 0.0001). CONCLUSION: Diets with the highest dairy content had higher nutrient composition, better diet quality, were associated with lower BP and financial cost, but with higher eutrophication potential. Robust environmental data for many of food groups are limited and this needs an urgent addressing. TRIAL REGISTRATION: This trial was registered on clinicaltrials.gov as NCT03407248.

Yogurt consumption is associated with higher nutrient intake, diet quality and favourable metabolic profile in children: a cross-sectional analysis using data from years 1-4 of the National diet and Nutrition Survey, UK.

PURPOSE: Yogurt consumption has been associated with higher nutrient intakes, better diet quality and improved metabolic profiles in adults. Few studies have investigated these associations in children. This study investigated the association of yogurt consumption with nutrient intakes, diet quality and metabolic profile in British children. METHODS: Data from  1687 children aged 4-10 and 11-18 years of the National Diet and Nutrition Survey (NDNS) years 1-4 were analysed. Yogurt consumption was determined using a 4-day diet diary. Diet quality was assessed by the Healthy Eating Index 2010 (HEI-2010). Anthropometric measures, blood pressure, pulse pressure, plasma glucose, HbA1c, C-reactive protein, triacylglycerol, total cholesterol, high-and low-density cholesterol from NDNS were used. RESULTS: The highest tertile of yogurt consumption (T3) was associated with higher nutrient intakes, particularly for calcium (children 4-10 years: P < 0.0001; children 11-18 years P = 0.001), iodine (both age groups P < 0.0001) and riboflavin (both age groups P < 0.0001), and HEI-2010 score (both age groups P < 0.0001) in children aged 4-10 years (mean ± SD: 98.4 ± 35.7 g yogurt/day) and 11-18 years (mean ± SD: 105.4 ± 37.5 g yogurt/day) compared with non-consumers (0 g yogurt/d). Yogurt consumption was associated with significantly lower pulse pressure in children aged 4-10 years and lower HbA1c concentration, being shorter and having a larger hip circumference in children aged 11-18 years, compared with non-yogurt consumers. CONCLUSION: This study suggests that British children who are yogurt consumers (> 60 g/day) have higher overall diet quality, nutrient intakes and adequacy, lower pulse pressure (children aged 4-10 years) and HbA1c concentrations (children aged 11-18 years), were shorter and had a smaller hip circumference (children aged 11-18 years).

Differential effect of beetroot bread on postprandial DBP according to Glu298Asp polymorphism in the eNOS gene: a pilot study.

Our objective was to investigate whether the presence of Glu298Asp polymorphism in the endothelial NO synthase (eNOS) gene differentially affects the postprandial blood pressure response to dietary nitrate-rich beetroot bread. A randomised, single-blind, controlled, crossover acute pilot study was performed in 14 healthy men (mean age: 34±9 years) who were retrospectively genotyped for Glu298Asp polymorphism (7GG; T carriers 7). Volunteers were randomised to receive 200 g beetroot-enriched bread (1.1 mmol nitrate) or control bread (no beetroot; 0.01 mmol nitrate) on two separate occasions 10 days apart. Baseline and incremental area under the curve of blood pressure and NOx (nitrate/nitrite) were measured for a 6-h postprandial period. A treatment × genotype interaction was observed for diastolic blood pressure (P<0.02), which was significantly lower in T carriers (P<0.01) after consumption of beetroot bread compared with control bread. No significant differences were observed in the GG group. The beneficial diastolic blood pressure reduction was observed only in the T carriers of the Glu298Asp polymorphism in the eNOS gene after consumption of nitrate-rich beetroot bread. These data require confirmation in a larger population group.