Tea’s impact on kidney stones
Kidney stones are a painful condition that affect millions of people. The Cleveland Clinic says researchers conclude one in 10 people will get a kidney stone in their lifetimes. Natural options to avoid kidney stones, such as drinking tea, may benefit some people. But the key may lie in which tea individuals consume.
Kidney stones typically form from various substances when there isn’t enough urine volume passing through the urinary system. Calcium, oxalate, uric acid, phosphate, and even cystine or xantine can become highly concentrated in the urine and crystalize into “stones.” A kidney stone may not be diagnosed until it moves out of the kidney into the ureter or urethra, where it can contribute to considerable pain. Symptoms of kidney stones include pain in the lower back, nausea or vomiting, fever or chills, blood in the urine, and inability to urinate.
Kidney stones have to come out one way or another. Some pass with urine and others require surgery. Anyone who has experienced kidney stones in the past likely does not relish their return, making kidney stone prevention a major goal. Drinking tea may help in those efforts, but it’s important to recognize that not all tea is effective.
Experts vary in their opinions on tea and its relationship to kidney stones. In 2013, the Mayo Clinic indicated drinking black tea may help lower the risk of kidney stones in some women. Drinking green or black tea also may reduce the risk of developing bladder cancer. However, other medical professionals state
that not all teas are the same in regard to preventing kidney stones. WEBMD reports that tea often is listed on the “avoid” list for those prone to oxalate kidney stones, as black teas have higher amounts of oxalate content that can exacerbate risk.
Data posted on Kidneystoners.org cites a 2003 study that found when healthy volunteers drank six cups of two types of black tea over a 24-hour period, the net result of drinking those cups of tea resulted in negligible increases or decreases in urinary oxalate excretion in urine.
Another study published in 1996 in the American Journal of Epidemiology suggested there’s a strong link between drinking tea and reducing risk for kidney stones.
People with a predisposition to oxalate kidney stones may be more sensitive to oxalate-containing teas. Green and oolong teas have lower oxalate amounts, so those may be the best teas for people vulnerable to kidney stones.
A September 2016 study published in the Asian Journal of Urology indicated blumea balsamifera, or sambong, decreased the size of laboratory-grown
calcium crystals. Sambong also may prevent the formation of these crystals. Sambong comes from a tropical shrub. In addition, coumarins, which are beneficial compounds found in the hydrangea shrub hydrangea paniculata, may have protective qualities for kidney health.
Individuals must carefully weigh the pros and cons of drinking tea in relation to kidney stone formation. Such individuals are urged discuss the pros and cons of tea with their physicians.