A 12-week course of a concentrated beetroot juice supplement, high in nitrates, was tested against a beetroot juice placebo that looked and tasted the same but had the nitrates removed.
Participants who were supplemented with the nitrate-rich juice displayed lowered blood pressure and could walk, on average, 30 metres farther in six minutes, the researchers, from Imperial College London, wrote in the European Respiratory Journal.
COPD – which includes chronic bronchitis and emphysema, causes breathing difficulties, severely limits people’s capacity for physical activity, and raises the risk of heart attack and stroke – has no cure, meaning there is interest in approaches that can help patients live with the condition.
The trial “shows that 12 weeks of oral nitrate supplementation in the form of beetroot juice lowers blood pressure, improves vascular function, and increases exercise capacity in people with COPD”, the authors concluded.
Nitrate-rich beetroot juice known to support cardiovascular health
Beetroots are a dietary source of nitrates that the body converts into nitric oxide, a bioactive known to support cardiovascular health. Previous research has shown that beetroot juice, naturally rich in nitrates, has potential as a treatment for peripheral artery disease.
The latest study included 81 people with COPD – a serious lung condition that, according to the World Health Organization, is the third leading cause of death worldwide – who were being treated at London’s Royal Brompton Hospital and whose systolic blood pressure measured higher than 130 millimetres of mercury (mmHg); the ideal range is between 90 and 120mmHg.
As well as monitoring patients’ blood pressure, the researchers tested how far patients could walk in six minutes at the beginning and end of the study.
Nitrate-rich beetroot supplement linked to improved exercise capability
Participants were randomly allocated to either receive the beetroot supplement (70 ml of concentrated beetroot juice, containing 400 mg of nitrate, once daily) or the placebo.
Researchers found that those taking the nitrate-rich supplement experienced an average reduction in systolic blood pressure of 4.5mmHg compared with those taking the placebo. There was also an average increase of around 30 metres in how far patients could walk in six minutes.
Professor Hopkinson said: “At the end of the study, we found that the blood pressure of people taking the nitrate-rich beetroot juice drink was lower and their blood vessels became less stiff. The juice also increased how far people with COPD could walk in six minutes compared to placebo.
“This is one of the longest-duration studies in this area so far. The results are very promising, but will need to be confirmed in larger, longer-term studies.”
Beetroot juice ‘has potential to be a safe treatment for COPD’
Professor Apostolos Bossios, from the Karolinska Institutet and Karolinska University Hospital in Stockholm, is head of the European Respiratory Society’s airway disease assembly.
He said: “COPD cannot be cured so there is a pressing need to help patients live as well as they can with the condition and to reduce their risk of cardiovascular disease.
“Patients taking part in this trial generally found the beetroot juice supplement acceptable and they saw benefits in terms of their blood pressure and mobility. This suggests they may see improvements in everyday life and should have a lower risk of heart disease and stroke, but we will have to study patients for longer to confirm if this is the case.
“Beetroot juice has been consumed widely and tested in other research, so it has the potential to be a safe treatment for people with COPD.”