Dietary nitrate does not modify blood pressure and cardiac output at rest and during exercise in older adults: a randomised cross-over study.

International journal of food sciences and nutrition. 2018;69(1):74-83

Plain language summary

Nitrates are naturally-occurring compounds that are produced within the body and also found in food. The main sources of nitrates in the diet come from cured meats and vegetables such as spinach, rocket and beetroot. Nitrate supplements have been associated with beneficial effects on heart and metabolic health, and improvements in athletic performance. Many of these benefits have been observed in younger adults. The objective of this randomised controlled trial was to investigate the effects of 7 days’ consumption of beetroot juice compared with placebo on (1) blood pressure (BP) measured in resting conditions and during exercise, (2) cardiac and peripheral vascular function and (3) biomarkers of inflammation, oxidative stress and endothelial integrity, in older adults. Twenty non-smoking healthy participants aged 60-75 years were recruited. Each participant was given 70ml of either beetroot juice rich in nitrates, or beetroot juice low in nitrates (placebo), twice a day for 7 days. All participants took both the 7-day courses, with at least 7 days rest in between. Measurement was conducted before and after each 7-day intervention period. Consumption of nitrates had no effect on resting systolic and diastolic BP. Nitrate consumption did not improve heart function during exercise. Nitrate consumption did not change markers of inflammation, oxidative stress and endothelial integrity. The authors concluded that this study does not support the short-term benefits of dietary nitrate supplementation on physiological and biochemical markers of heart health in older healthy adults.

Abstract

Dietary nitrate (NO3-) supplementation has been associated with improved vascular and metabolic health. We conducted a double-blind, cross-over, placebo-controlled RCT to investigate the effects of 7-d consumption of beetroot juice compared with placebo on (1) blood pressure (BP) measured in resting conditions and during exercise, (2) cardiac and peripheral vascular function and (3) biomarkers of inflammation, oxidative stress and endothelial integrity. Twenty non-smoking healthy participants aged 60-75 years and BMI 20.0-29.9 kg/m2 were recruited. Measurement was conducted before and after each 7-d intervention period. Consumption of NO3- had no effect on resting systolic and diastolic BP. NO3- consumption did not improve indexes of central and peripheral cardiac function responses during cardiopulmonary exercise testing. Dietary NO3- supplementation did not modify biomarkers of inflammation, oxidative stress and endothelial integrity. This study does not support the short-term benefits of dietary NO3- supplementation on physiological and biochemical markers of vascular health in older healthy adults.

Lifestyle medicine

Fundamental Clinical Imbalances : Immune and inflammation ; Structural
Patient Centred Factors : Mediators/Nitrates
Environmental Inputs : Nutrients
Personal Lifestyle Factors : Nutrition ; Exercise and movement
Functional Laboratory Testing : Blood ; Urine
Bioactive Substances : Nitrates ; Nitric oxide

Methodological quality

Jadad score : 3
Allocation concealment : Yes

Metadata