Researchers from the University of Texas Southwestern Medical Center at Dallas studied 13 volunteer patients in a multi-phase trial funded by the U.S. National Institutes of Health. The volunteers -- some with a history of kidney stones and some without -- drank 13 ounces of a specific beverage three times a day with low-calcium, low-oxalate meals for one week, followed by a three-week interval. The participants drank distilled water for the first phase of the trial, followed by orange juice for the second phase and lemonade for the third phase.
The researchers found that drinking orange juice increased the levels of citrate in the participants' urine and reduced the crystallization of uric acid and calcium oxalate -- two components that can lead to the formation of kidney stones. Lemonade and water did not increase citrate levels.
Dr. Clarita Odvina, the study's lead author, says that the citrate in orange and grapefruit juices is accompanied by a potassium ion, which does not counteract the beneficial effects of high citrate content. Conversely, the citrate in lemonade and cranberry juice is accompanied by a hydrogen ion, which counteracts the positive effects of high citrate.
"What we see with this research is that, once again, nature has provided us with the answers for preventing health problems," explained Mike Adams, a holistic nutritionist and author of The Seven Laws of Nutrition. "All we have to do is consume a variety of fresh, unprocessed fruits and vegetables on a daily basis, and we are automatically preventing kidney stones, cancer, heart disease, Alzheimer's disease, depression, diabetes and countless other health conditions," he said.
Adams recommends that consumers drink fresh, unprocessed orange juice to receive the greatest health benefits. "I do not recommend pasteurized orange juice or reconstituted juice of any kind," he said. "The greatest health benefits are derived from drinking raw, fresh fruit and vegetable juices, straight from nature."