Beets and beetroot juice have been anointed with “superfood” status due to a substantial amount of research focusing on the beneficial effects of beetroot juice on exercise performance and blood pressure reduction.
To some, this research may sound somewhat questionable.
However, there is growing scientific support for the benefits of beetroot juice and other foods that contain chemicals that promote the body’s productions of nitric oxide or NO.
QUESTION: How does beetroot juice increase NO?
ANSWER: Red beets are naturally high in compounds called nitrates and nitrites which have a history of use as food additives with a bad reputation linked to possible increased cancer risk. These chemicals, however, contribute to the production of nitric oxide which is well known for its ability to promote vasodilation — relaxation and expansion of the diameter of blood vessels and reduced blood pressure.
The naturally high amount of nitrates and nitrites in many vegetables, such as spinach and Chinese vegetables like bok choy, made this cancer concern somewhat questionable. Now, naturally occurring nitrates and nitrites are being considered as one of the likely reasons vegetables provide health benefits.
Q: How much beetroot juice is needed to lower blood pressure?
A: Studies using doses as little as 2 to 3 ounces of beetroot juice per day have produced significant declines in blood pressure in some individuals. These effects have been observed within a few hours and continue with ongoing daily use.
Q: Are all beetroot juices the same?
A: No. Commercial varieties of beetroot juice vary greatly in the amount of nitrate they contain. Some contain almost none and others are very high. The amount of nitrates and nitrites in vegetables also can vary widely due to different growing conditions such as soil composition, weather and season.
Q: Can beetroot cause urine or stool to become red?
A: Although red urine can be alarming, poorly digested betacyanins can be absorbed from beet juice and cause urine or stool to be colored pink or red. Previously this phenomenon was thought to be related to genetics, but it is now known to be caused by decreased stomach acid production and is more common in individuals with iron deficiency or gut malabsorption issues.
Q: Are there supplements or drugs that provide controlled doses of nitrates and nitrites?
A: Yes. Nitroglycerine has been used for treating people with cardiovascular problems. It basically provides a measured dose of nitrate — usually in a time-released form. Since nitroglycerine has potential side effects, researchers are studying the use of various forms of nitrate and nitrite (sodium nitrate and sodium nitrite) in carefully controlled oral doses or intravenous infusion. So far, the drug research shows similar results as using beetroot juice with known amounts of nitrate and nitrite.
Alan Titchenal, Ph.D., C.N.S., and Joannie Dobbs, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa. Dobbs also works with University Health Services.
