5 drinks that are good for people with kidney disease and those that should be avoided

The kidneys constantly filter blood to remove waste and balance water and salt in the body. Therefore, what you drink can directly affect the functioning of the kidneys, from maintaining body water levels, controlling blood pressure, blood sugar, to the risk of kidney stones or urinary tract infections. For people with kidney diseases such as chronic kidney failure or impaired kidney function, choosing the right drinks can help protect the kidneys, reduce complications and improve quality of life.

1. Some drinks are good for people with kidney disease

1.1. Water is a necessary foundation

Water is the most important component for kidney function, helping to make urine, remove toxins, and maintain stable blood pressure. Many observational studies suggest that adequate water intake is associated with a lower risk of kidney disease and reduced recurrence of kidney stones.

However, a 1-year study in patients with chronic kidney disease found that drinking more water than usual did not slow the rate of decline in kidney filtration function (GFR). This suggests that fluid volume needs to be individualized for each patient (especially those with end-stage kidney disease or on dialysis). Patients should talk to their doctor to determine the appropriate amount of water based on GFR, symptoms of edema, and weight.

Accordingly, for most people with kidney disease who are not in the end-stage renal failure, priority should be given to maintaining adequate hydration and avoiding frequent dehydration. For people with end-stage renal failure or on dialysis, drink water according to professional guidelines on daily fluid intake limits.

1.2. Low-fat milk provides calcium, vitamin D, potassium and magnesium

Epidemiological studies have shown that consuming low-fat dairy products is associated with a slower rate of decline in kidney function in some groups of people than consuming no or high-fat dairy products. The vitamins, minerals, and nutrients in milk (calcium, vitamin D, magnesium) may help control blood pressure and many cardiovascular risk factors — indirectly protecting the kidneys. Note that whole (high-fat) milk has not been shown to have the same benefits.

Accordingly, choose low-fat milk or low-fat dairy products; if potassium/phosphorus control is needed (in people with severe chronic kidney disease), consult a doctor or nutritionist to adjust the appropriate amount.

1.3. Coffee is beneficial but should be consumed in moderation

Several large meta-analyses have shown that coffee consumption is associated with a reduced risk of developing kidney disease in people without advanced disease (e.g., results from the ARIC study). However, a clear benefit in people with already poor kidney function has not been confirmed.

Additionally, caffeinated coffee can increase potassium and affect blood pressure in some people. Therefore , drink coffee in moderation (no more than 2–3 cups/day), and avoid varieties with syrups, creamers, or added powders that are high in sugar, potassium, or phosphorus. If caffeine increases blood pressure, consider decaffeinated coffee.

1.4. Green tea provides beneficial antioxidants

Green tea contains EGCG and other catechins that have anti-inflammatory and antioxidant properties. Preclinical studies and some analyses suggest that green tea may help reduce the risk of kidney stones and benefit kidney tissue in experimental models.

However, human evidence is still needed. Moderate green tea consumption as part of a healthy diet is generally considered safe and beneficial.

1.5. Unsweetened cranberry juice prevents urinary tract infections

Cranberries are rich in proanthocyanidins, which may prevent bacteria from adhering to the lining of the urinary tract. A Cochrane review and meta-analysis found that cranberries are effective in reducing the recurrence of urinary tract infections in people prone to recurrence.

For kidney patients, preventing urinary tract infections (UTIs) is important, as recurrent UTIs can lead to pyelonephritis. When using, choose sugar-free/low-sugar products to avoid hyperglycemia and hypertension.

2. Drinks to limit or avoid

People with kidney disease should avoid drinks such as:

- Cola drinks (contains phosphoric acid): Associated with increased risk of kidney stones and phosphate-induced kidney damage; studies suggest high cola consumption is harmful to the kidneys.

- Sugary drinks (sodas, high-sugar juices, energy drinks): Increase the risk of diabetes, high blood pressure, and inflammation — all of which are factors that promote kidney failure.

- Alcohol: Heavy drinking can reduce the kidney's filtering capacity and increase blood pressure. For patients with underlying medical conditions, alcohol can be a risk factor. Moderate consumption still needs to be carefully considered according to individual health status.

3. Some notes

- Individualization: There is no “one size fits all” regimen. The amount of water, milk, or fruit/functional drinks should be adjusted according to your GFR, blood potassium/phosphate, blood pressure, and whether you are on dialysis.

- Preferred beverages: Water, low-fat milk (if appropriate), green tea, and unsweetened cranberry juice are reasonable choices. Coffee can be beneficial, but drink in moderation and avoid sugary additives.

- Consult a specialist: For people with chronic kidney disease stages 3 - 5, on dialysis, or with electrolyte disorders, consult a nephrologist/nurse or clinical nutritionist before changing fluid intake or adding functional foods.

Note, this article is for informational purposes only and cannot replace medical advice for specific cases.