High Sugar Consumption Linked to Kidney Stones

Many who have had kidney stones say it’s one of the most painful experiences of their life. While there are many factors that contribute to developing a kidney stone, a new study suggests that high sugar intake increases your chances of developing a kidney stone by nearly 40 percent.

Kidney stones are hard deposits of minerals and acid salts that stick together to make what looks like a small pebble. They are created when crystal-forming substances like calcium, oxalate and uric acid in your urine are in a higher concentrations than the fluid can dilute. And the pain is experienced when that stone is passing through the urinary tract.

It is estimated that between 7 and 15 percent of people in North America develop kidney stones. Common symptoms include pain, nausea, vomiting, fever, chills and bloody urine. Anyone can get one, but they are more prevalent in men.

Previously known risk factors include obesity, dehydration, chronic diarrhea, inflammatory bowel disease, diabetes and gout. And now, added sugars, which are found in processed foods like sodas, fruit drinks, candy, ice cream, cakes and cookies can be added to the list according to research from scientists at the Affiliated Hospital of North Sichuan Medical College, Nanchong, China.

"Ours is the first study to report an association between added sugar consumption and kidney stones," said lead author Dr. Shan Yin. "It suggests that limiting added sugar intake may help to prevent the formation of kidney stones."

Yin and fellow researchers analyzed data from more than 28,000 men and women from the US National Health and Nutrition Examination Survey (NHANES). Participants self-reported any history of kidney stones and also completed multiple food intake surveys.

They were given a healthy eating index score based on their responses. They were then categorized based on the percentage of their daily caloric intake that came from added sugars.

Those with the highest percentage of caloric intake from sugar had the highest likelihood of developing kidney stones. The top 25 percent of people in terms of sugar intake had 39 percent greater odds of developing kidney stones during the study period than the rest of the participants. And when that same group was compared to the bottom 5 percent in terms of sugar intake the risk was 88 percent higher.

The reason sugar was associated with kidney stones has not yet been identified. Researchers acknowledged because it was an observational trial, it’s possible there were some confounding factors that may have contributed to the sugar-kidney stone association.

"Further studies are needed to explore the association between added sugar and various diseases or pathological conditions in detail," Yin said. "For example, what types of kidney stones are most associated with added sugar intake? How much should we reduce our consumption of added sugars to lower the risk of kidney stone formation? Nevertheless, our findings already offer valuable insights for decision-makers."

Click here to read more in the journal Frontiers in Nutrition.