Food and drink can influence some urinary conditions, particularly recurrent kidney stones. A balanced eating pattern also supports general health. But the evidence does not support calling individual foods “urology-friendly” treatments or claiming that a berry, seed or spice will prevent urinary tract infections (UTIs), prostate enlargement or cancer. The useful advice depends on the diagnosis and the person.[1–4]

 

Start with the whole diet

The Australian Dietary Guidelines recommend a variety of vegetables, fruit, wholegrain foods and suitable protein foods, while limiting foods high in salt.[1] That is a more reliable starting point than a list of purported “superfoods.” People with kidney disease, recurrent stones or other medical conditions may need more specific advice from their treating team.

1. Berries and the cranberry question

Blueberries, strawberries and raspberries can be enjoyed as fruit, but evidence about cranberry products should not be extended to all berries. A Cochrane review of 50 trials found that cranberry juice, tablets or capsules probably reduce symptomatic, culture-confirmed UTIs in women with recurrent UTIs, and found benefit in some other groups. It found little or no clear benefit in several other populations. Product preparations and doses differ, and no standard effective dose has been established.[3]

Cranberry products are a possible prevention measure for selected people, not a treatment for an infection that is already present. Recurrent urinary symptoms also warrant assessment: not every episode of burning or urgency is caused by a bacterial UTI.[3]

2. Watermelon, water and kidney stones

 

Watermelon contributes fluid and can be part of a varied diet, but it has no special “detoxifying” action. The kidneys filter blood continuously; eating watermelon does not flush out a diagnosed infection or stone.

For many people with recurrent stones, adequate fluid intake is one of the better supported preventive measures. European Association of Urology (EAU) guidance recommends enough fluid, preferably water, to produce more than 2.5 litres of urine in 24 hours for stone prevention.[2] This is a urine output target, not an instruction for everyone to drink a fixed amount of water. Fluid needs vary with heat, activity and health conditions. People with a prescribed fluid restriction, including some with kidney or heart disease, should follow individual advice.[2, 8]

3. Leafy greens and oxalate

Vegetables are part of a healthy eating pattern. There is no reason for everyone to avoid spinach or other leafy greens. However, spinach contains substantial oxalate, which can matter for some people with calcium oxalate stones and high urinary oxalate. In that setting, limiting excessive intake of high-oxalate foods may be useful.[2]

Stone prevention is more nuanced than cutting out one vegetable. Stone composition, blood tests and sometimes a 24-hour urine collection can guide advice. EAU guidance generally discourages restricting normal dietary calcium, since adequate calcium intake can help reduce intestinal oxalate absorption; advice on supplements is different and should be individualised.[2]

4. Fish and dietary protein

Fish is one protein choice within the Australian Dietary Guidelines.[1] Oily fish contains omega-3 fats, but there is insufficient clinical evidence to claim that eating it treats bladder inflammation or prevents a particular urological disorder.

For some stone formers, the overall amount of animal protein may be more relevant than selecting one type of fish. Excess animal protein can change urine chemistry in ways that favour stone formation. Any change should fit the person’s nutritional needs and stone risk profile.[2]

5. Pumpkin seeds and prostate health

Pumpkin seeds can contribute nutrients, including zinc, to a varied diet. That does not mean they prevent benign prostate enlargement or prostate cancer, or replace assessment of urinary symptoms. Cancer Council Australia concludes that evidence about specific dietary factors is insufficient to recommend a food or supplement for prostate cancer prevention.[4]

“Natural” supplements are not automatically beneficial. For example, a large prevention trial found an increased prostate cancer risk in men assigned vitamin E alone, illustrating why a plausible biological theory is not enough to justify a prevention claim.[5]

6. Turmeric: food versus supplements

Turmeric is a spice; curcumin is one of its constituents. Laboratory findings about inflammation do not demonstrate that adding turmeric to meals prevents or treats urinary disease. The US National Center for Complementary and Integrative Health says there is not enough evidence to draw firm conclusions about many proposed health benefits of oral turmeric or curcumin.[6]

Concentrated supplements are different from ordinary culinary use. Some formulations designed to increase curcumin absorption have been associated with liver injury. Tell your treating clinician about supplements, particularly before an operation or when taking regular medicines.[6]

Practical steps if you have urinary symptoms

For someone with recurrent kidney stones, the strongest dietary starting points are usually appropriate fluid intake, avoiding excess salt and adjusting diet based on stone type and urine results. EAU guidance recommends a mixed diet and generally advises against restricting normal dietary calcium.[2] For someone with recurrent UTIs, the priority is to confirm the diagnosis and consider the full range of prevention options; cranberry is one possible measure for certain groups, with limits to the evidence.[3]

Diet cannot replace assessment of blood in the urine, persistent pain, fever with urinary symptoms, difficulty passing urine or repeated infections. If you have these symptoms, speak with your GP or treating clinician. Advice can then be tailored with input from a urologist or accredited practising dietitian where needed.

This is general educational information, not an individual treatment plan. No food or supplement discussed here is presented as a cure or as a substitute for appropriate medical care.

References

1. National Health and Medical Research Council. Australian Dietary Guidelines.
2. European Association of Urology. Guidelines on Urolithiasis: Metabolic Evaluation and Recurrence Prevention.
3. Williams G, et al. Cranberries for preventing urinary tract infections. Cochrane Database of Systematic Reviews, 2023.
4. Cancer Council Australia. Prostate cancer prevention.
5. US National Cancer Institute. Selenium and Vitamin E Cancer Prevention Trial (SELECT).
6. US National Center for Complementary and Integrative Health. Turmeric: Usefulness and Safety.
7. Kidney Health Australia. Kidney stones.
8. Healthdirect Australia. Drinking water and your health.