Behind the headlines: What are the hearty benefits of beetroot?
Key Takeaways
Beetroot, which is rich in nitric oxide, is a vital chemical for a healthy cardiovascular system.
More data is needed to determine whether or not beetroot can reduce the risk of heart attacks, so articles promoting this idea must not be taken at face value.
A daily glass of beetroot juice could help with coronary heart disease and even reduce heart attacks — according to recent news reports. But are these claims supported by good evidence?
The research from Queen Mary University of London claims that a 140ml daily glass of beetroot juice could increase levels of nitrate oxide, helping to reduce harmful inflammation.[]
Media articles claimed that drinking this “could reduce the risk of heart attacks for people with heart disease” and even “speed up healing,” presenting a daily dose of beetroot juice as a potential solution for those with heart disease.[]
Unfortunately, what is reported by the study makes these claims seem premature in their proclamations.
What do we know so far?
The research, funded by the British Heart Foundation (BHF), was presented at the British Cardiovascular Society Conference on 6-8 June 2022.[] It looked at whether daily consumption of beetroot juice could increase levels of nitric oxide — and whether this affected inflammation within the body.
Nitric oxide helps regulate blood pressure and has anti-inflammatory effects. Though the body produces it naturally, people with heart and circulatory conditions have lower levels. Beetroot juice has high levels of inorganic nitrate.
The study involved 114 volunteers; 36 were given small blisters to test localized inflammation, while 78 were given the typhoid vaccine — which temporarily stimulates a mild inflammatory response in blood vessels.[]
Half the volunteers drank high-nitrate beetroot juice, while the rest had juice with nitrate removed.
In the typhoid vaccine group, the high-nitrate group had higher levels of nitric oxide in their saliva, urine, and blood. They had lower circulating levels of inflammatory monocytes, a type of white blood cell, and the monocytes in their blood became more anti-inflammatory. It was also found that the high-nitrate juice seemingly restored the function of endothelium, cells lining the inside blood vessels, which lose their function in inflammation.
The blisters healed more quickly in the high nitrate group, with lower numbers of inflammatory white blood cells in fluid samples.
Lead Researcher, Asad Shabbir, MD, explained that these results could help people with heart problems.
"In people with coronary heart disease persistent inflammation can exacerbate the furring of the arteries, making their condition worse and increasing their risk of a heart attack."
— Asir Shabbir, MD
However, this study was small-scale — only 114 volunteers, and all healthy. Researchers are planning clinical trials in people with coronary heart disease, but the effects have not yet been replicated in this group. Despite this, speculation that it could help those with heart disease was greatly emphasized in media reports.
The volunteers also only drank beetroot juice for seven days. Fluid samples from blisters were taken after three days. This means it is not clear if the effects seen would persist in the long-term, or whether there could be any other impacts.
So far, only an abstract of the research has been presented, and remains unpublished, so full details of the study methodology and results are yet to be revealed.
Why beetroot?
A body of evidence is building that nitric oxide is a vital chemical for a healthy cardiovascular system.[]Although it is produced naturally, introducing more dietary nitrate could help prevent or even improve heart conditions.[]
Beetroot is only one way of doing this — it actually has a lower mean nitrate content than green leafy vegetables like spinach, rocket or lettuce. Beetroot is not a solo "superfood" — Shabbir stated that “our research suggests that a daily glass of beetroot juice could be one way to get inorganic nitrate into our diet to help to interrupt harmful inflammation."
However, it has become a focus of research, with a study published earlier this year reporting that “beetroot juice is a convenient source of [inorganic nitrate], especially compared to whole-food sources, and is now considered a key research area in this field.”[]
Shannon Amoils, MD, Senior Research Advisor at the British Heart Foundation, speaking in 2015 about a study into beetroot juice lowering blood pressure, said: “The possibility of using a natural product, rather than another pill, to help lower blood pressure, is very appealing.”[] This may help to explain why there is often such media reaction to this sort of research, even when it is preliminary and small-scale.
The challenge of nutritional studies
The media stories highlight a typical problem with reporting scientific advances, and the challenge of reporting on nutrition in particular.
Nutritional trials are often smaller, and it is difficult to control diets absolutely, which leads to imprecise and sometimes contradictory results.[] Yet, they attract a lot of public interest — even when results have not been repeated in larger groups.[]
In fact, another small study, published in May 2022, showed that nitrate-rich beetroot juice had little or no discernible impact on the endothelium — contradicting the findings reported at the British Cardiovascular Society Conference. This is a common occurrence, and why larger trials, systematic reviews and meta-analyses remain important in nutrition science.[]
A 2017 study indicated that “exposure to contradictory nutrition information produces greater nutrition confusion and backlash, which ultimately reduces engagement in a recommended nutrition behavior." []
While the dietary nitric oxide that beetroot juice provides may well be beneficial for heart conditions, and has potential as an ongoing area of research, reporting on it as definitely "reducing the risk of heart attacks" is potentially unhelpful, which must be viewed with caution.