Beet juice is an excellent source of calcium, folate, potassium, manganese, iron, vitamin C, fiber and antioxidants. Other studies have linked beet juice with a reduction in blood pressure and the prevention of stomach and colon cancer. Clinical studies reported in Hypertension magazine support drinking at least two cups of beet juice a day, but the juice can have side effects.
In some people, beet juice may cause red urine. This is known as beeturia. It does not happen in all people as some digest beets better than others. Researchers are still working to figure out why this happens to people, but it may be possible that much like with dairy products and lactose, some people have the enzymes to process the juice and others lack them. Those lacking them are more likely to experience beeturia.
Temporary Vocal Paralysis
In some people, beet juice may temporarily paralyze vocal chords by tightening them. This is not an uncommon reaction and may be, in essence, a form of allergy. However, there is little research into the exact causes. If you find you have trouble talking after drinking beet juice, don't worry, it will pass. Mixing beet juice with other juices may help to reduce this effect.
Drinking larger amounts of beet juice may create dizziness in the drinker. The causes of this are not completely known, but clinical studies have confirmed that two cups or more a day of beet juice can reduce blood pressure; the resulting drop may be responsible for some people's dizziness.
Much like with the vocal chord paralysis, this effect will pass.
Like with all foods, some people are allergic to beets and beet juice. This can cause rashes, swelling, even anaphylactic shock. Researchers at De Montfort University found that a gene in sugar beets is related to the allergen in latex. People who are allergic to latex may have a similar reaction to sugar beets.