A collaboration with Jen Robinson
There has been some really interesting research recently about the uses of beetroot juice to reduce blood pressure and even claims it can enhance athletic performance. What does science say and how does it work?
There is a growing body of research suggesting that drinking beetroot juice can widen our blood vessels, which leads to a reduction in blood pressure and also increases blood flow to our muscles, which has the potential to enhance athletic endurance.
How does it work?
Beetroot, along with many other vegetables, are high in compounds known as nitrates. When our body digests nitrate it undergoes chemical reactions and is converted to something called nitric oxide, which is then absorbed into our blood stream.
Nitric Oxide is also naturally produced by our blood vessels when they need to dilate (become wider). Blood vessels dilate during exercise as wider blood vessels allow the oxygen in our blood to reach our muscles faster, allowing faster gas exchange, faster energy production and increased strength of muscle contraction. In addition to this, blood vessels also produce nitric oxide as part of the body’s natural mechanism to reduce our blood pressure if it becomes too high; if a blood vessel is wider the blood flowing through it will be under less pressure (to visualise this imagine what happens to the water flowing out of a hose wipe when you squeeze it and make it narrower, then when you release it and make it wider!)
So studies have investigated whether increasing the amount of nitrate that we eat, has the effect of increasing the amount of nitric oxide circulating in our bodies to lower our blood pressure and/ or improve athletic performance.
What Does the Science Say?
There are a growing number of studies that have shown that the consumption of nitrate-rich foods like beetroot can reduce blood pressure.
For example, this study found that systolic blood pressure and diastolic blood pressure decreased by 22·2mmHg and 18·3mmHg respectively. Blood pressure returned to normal around 4 hours after consumption, however, further research is needed as this is a substantial reduction in blood pressure which could make a difference in patients with high blood pressure.
There is also a growing number of studies demonstrating that beetroot can be beneficial in athletic performance, however, many studies publish conflicting results and more work is needed.
However a recent systematic review investigated the effects of beetroot juice supplementation on Cardiorespiratory Endurance in Athletes, and concluded that the available results (from 23 good quality studies) suggest that supplementation with beetroot juice can improve cardiorespiratory endurance, improve performance in athletes at various distances, and increases the length of time before exhaustion at submaximal intensities. Beetroot juice may also improve the cardiorespiratory performance at anaerobic threshold intensities and maximum oxygen uptake.
After completing the 10-week #FightTheFadsFriday series with Jen Robinson we are happy to announce that there is going to be a new edition each week! Jen Robinson is a graduate medical student and blogger in her final year at UCL. She is passionate about food, public health and improving nutrition education for tomorrow’s doctors. Make sure to follow her on Facebook, Twitter and Instagram.