Beetroot juice has been in the news a lot in the last few months. There have been a fair number of studies in the past few years using it as an athletic performance enhancer and to lower blood pressure, improve heart function in angina patients and for a number of other possible uses. It is one the high potassium foods with a lot of other advantages also.
Beetroot should first of all be distinguished from the sugar beet. Starting from a common ancestor, the sugar beet was selectively bred for its sugar content to compete with sugar cane and is mostly white. Beetroot is red to purple and also called garden beet. It has betaine and a number of other phytochemicals that may have advantageous health benefits. What has been getting all the press lately though is the fact that it is high in nitrates.
Because it is high in nitrates, it has many of the same effects as the nitrate medications that are used with angina patients. When given acutely they will dilate blood vessels and can relieve angina.
Beetroot juice has been studied for this effect, but also for other uses, such as lowering blood pressure and improving athletic performance. The effects have been examined in short term studies though. The use for lowering blood pressure was studied for its effects in males with normal blood pressure and blood pressure was lowered for the 24 hours that the study was run. Long term effects on blood pressure are unknown.
Likewise, it has been used in a lot of different athletic settings. Rowers, runners, steppers, cyclists and resistance exercisers have been given the juice for anywhere from a few hours up to 24 hours prior to an athletic performance test, with an occasional study supplementing for as much as 6 days. The majority of studies have shown improvement in performance. The main improvement is in the later part of the exercise session, indicating it improved the ability of the muscle to endure. It helps to overcome the hypoxia (low oxygen delivery to the muscle) that occurs with exercise as it continues.
Animal and some human studies have looked at the muscles and the small blood vessels in the muscles. The small blood vessels do not clamp down as much as usual as exercise continues, so they deliver more oxygen to the muscle. Also the muscle cells have better functioning mitochondria, which are the energy factories of the cell. The mitochondria can continue to provide more energy under reduced oxygen conditions than they could without the beetroot juice consumption.
Because of its high nitrate content, the way the beetroot juice may work is that it delivers nitrites and more importantly nitric oxide to the cells. This works on the small blood vessels by keeping them open longer during exercise and works on the mitochondria by improving their management of oxygen in the cell.
However, nitrate tolerance may limit its usefulness if used daily. Nitrate tolerance has been known for over a hundred years for the nitrate medications. Higher and higher doses are needed to get the favorable effects. But there are forms of nitrate molecules that show less tolerance and it may be that beetroot juice has nitrate in such a form. Studies that use beetroot juice for longer periods would help determine its long term effects.
So what is the bottom line? At this point, beetroot juice appears to help you exercise longer if you take it several to 24 hours prior to your exercise session. It helps you reduce your blood pressure in the short term. If you take it daily, you may gradually lose the blood pressure lowering and performance enhancing effect.
But if you include it once or twice a week you will be able to exercise longer during one or two sessions, and will be getting a great boost of potassium. That boost can help you get the 4700 mg of potassium a day that has been shown to help with long term blood pressure reduction. Check the list of posts for other articles on blood pressure reduction with high potassium foods.