Research suggests cranberry juice may actually increase kidney stone formation, rather than helping as many believe. You may consider limiting your cranberry juice to 1 cup or less a day, and choosing other citrus juices like orange, lemon, apple, or black currant.

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Kidney stones are a common disorder, affecting around 1 in 11 adults in the United States (1).

While there are many causes of kidney stones, diet plays a major role. In particular, cranberry juice is thought to help get rid of kidney stones, similarly to how it reduces incidence of urinary tract infections (UTIs).

That said, some experts argue that drinking cranberry juice may actually worsen your kidney stones. Due to conflicting opinions, you may be confused and unsure what to believe.

This article tells you if cranberry juice is good for kidney stones or if you’d be better off avoiding it.

What are kidney stones?

Also known as nephrolithiasis, kidney stones are solid crystals made from chemicals in the urine. It’s estimated that around 600,000 Americans experience kidney stones each year (1, 2).

The main types of kidney stones that exist include calcium oxalate, calcium phosphate (brushite), uric acid, struvite (magnesium ammonium), and cysteine. They vary in size, from a small grain to even the size of a golf ball, but those are rare (1, 2).

The most common form of kidney stones is calcium oxalate, which account for around 32–46% of cases (1).

While there is no specific cause of kidney stones, there are certain factors that increase your risk, such as (1, 2):

• chronic dehydration (e.g., from low fluid intake or excessive sweating)
• consuming a diet high in protein, oxalates, phosphoric acid, fructose, salt, and sugar
• obesity
• certain medications (e.g., antibiotics, diuretics, laxatives, sulfonylureas, potassium channel blockers, etc.)
• overuse of certain supplements like vitamin C
• genetics and family history of kidney stones
• recurring urinary tract infections (UTIs)
• comorbidities (e.g., high blood pressure, gout, non-alcoholic fatty liver disease, gastrointestinal disease, hyperparathyroidism, nephrocalcinosis, sarcoidosis)
• certain surgical procedures like gastric bypass

A person with kidney stones may present with abdominal or back pain as the kidney stone travels from the kidneys to the bladder. They may also experience nausea, vomiting, malaise, fever, chills, and blood in the urine (1).

Summary

Kidney stones are solid crystal formations that develop in the kidneys. Though there are many causes of kidney stones, low fluid intake, diet, and genetics play a major role.

Should people with kidney stones drink cranberry juice? 

Using cranberry juice to treat kidney stones is a contested topic with mixed research. Plus, many of the studies into potential relationships between cranberry juice and kidney stones are older, so we need more research to be sure.

Cranberry juice is high in oxalates, which can increase your risk of calcium oxalate kidney stones. This is because oxalates bind to calcium when you consume a lot of them, especially if you’re already prone to kidney stones (3, 4).

Additionally, one older study found that cranberry juice decreased urinary citric acid excretion, which can contribute to the development of kidney stones. However, another older study found that cranberry juice did not affect citric acid levels (5, 6).

Further, some research suggests that cranberry juice lowers the pH of urine, making it more acidic. Increased acidity can raise the risk of developing calcium oxalate and uric acid stones (5, 6, 7).

A recent review also found that cranberry juice increased relative supersaturation risk (RSR) of calcium oxalate and uric acid stones. RSR measures one’s risk of developing kidney stones, with a higher score increasing risk (7).

Interestingly, cranberry juice decreased RSR scores for brushite and struvite stones, since these stones are less likely to develop in acidic environments (7).

That being said, another older study found that cranberry juice decreased RSR for calcium oxalate stones and increased urinary pH, contradicting other studies (8).

Currently, most research suggests that the effects of cranberry juice may depend on which type of stones you tend to develop. If you’re susceptible to calcium oxalate and uric acid stones, it may be best to limit or avoid cranberry juice (7).

Further, there is no data that compares the effects of 100% cranberry juice or processed cranberry beverages and kidney stone formation. It’s probably best to select 100% juice, as it doesn’t contain added sugar or other unwanted ingredients.

While cranberry juice consumption may play a role in kidney stone formation, there are many types of kidney stones with various causes. Therefore, it’s best to work closely with a healthcare professional for personalized treatment and recommendations.

Summary

Some research suggests that cranberry juice may increase risk of calcium oxalate and uric acid stones, especially if you’re prone to kidney stones. However, we need more up-to-date studies.

Alternatives to drinking cranberry juice for kidney stones

If you’re looking for an alternative to cranberry juice, there are some other healthy options.

Currently, research suggests that juices high in citric acid may reduce risk of developing calcium oxalate kidney stones, since citric acid may inhibit stone formation. It may also increase urinary pH, making the urine more alkaline (4, 7, 9).

In particular, orange juice appears to be the best choice in terms of its citric acid and alkalizing properties. Black currant and lemon juices may also be good options for people prone to calcium oxalate or uric acid stones (4, 7, 9).

Additionally, apple juice may also be a good alternative since it’s high in malic acid — a precursor to citrate — but more research is needed (10, 11).

Remember: juice is high in sugar and lower in fiber than whole fruit and vegetables, making it a less nutritious option. If you choose to drink juice, it’s best to limit your intake to around a cup (236 mL) per day.

Summary

Juices that are high in citric acid (e.g., orange, blackcurrant, and lemon) or malic acid (e.g., apple juice) may help prevent the formation of kidney stones.

The bottom line

Kidney stones are hard crystals that are formed from chemicals in the urine. They’re often caused by chronic dehydration, diet, genetics, medications, and other lifestyle factors.

Cranberry juice has been thought to help with kidney stones, but research suggests that it may actually increase kidney stones formation — especially calcium oxalate stones, which are the most common kidney stones.

Ideally, you should try to limit your juice intake to around one cup (236 mL) or less per day. You may be better off choosing citrus juices (e.g., orange, black currant, lemon) or apple juice, which are linked with lower risk of kidney stones.

If you’re susceptible to kidney stones — especially calcium oxalate stones — it may be best to avoid cranberry juice or speak with a healthcare professional before consuming it.

Just one thing

Try this today: Staying hydrated can help prevent kidney stones and other health issues. Check out this article for tips and tricks to drink more water, and this article for some foods and drinks that may help you stay hydrated.