Controlled Diet for Kidney Stone Prevention

Overseen By Sonia Fargue, M.D., Ph.D.

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of Alabama at Birmingham

Disqualifiers: Kidney stones, Diabetes, Hepatic disease, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

40 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how a controlled low oxalate diet might help prevent kidney stones, particularly concerning obesity. Researchers aim to understand how obesity affects the production of oxalate, a substance linked to kidney stone formation. Participants will be grouped by body mass index (BMI) to assess the diet's impact. Adults who have never had kidney stones and have a BMI under 50 may qualify for this trial. As an unphased trial, it offers participants the chance to contribute to groundbreaking research on diet and kidney health.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What prior data suggests that this controlled diet is safe for kidney stone prevention?

Research has shown that a controlled diet can reduce the risk of kidney stones. Studies have found that consuming foods low in oxalate, a substance that can lead to stone formation, is crucial for prevention. While these studies focus on prevention, they report no serious side effects from such a diet.

Overall, a controlled diet is considered safe. It mainly involves monitoring food intake, such as reducing salty foods and avoiding excessive sugar. Current guidelines and studies indicate no known serious issues from following these diets. A balanced, low-oxalate diet is commonly recommended for those prone to kidney stones and is generally well-tolerated. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the controlled diet for kidney stone prevention because it offers a non-invasive, lifestyle-based approach that could reduce the risk of stone formation. Unlike standard treatments, which often involve medications like thiazide diuretics or citrate supplements, this diet focuses on altering nutrient intake to manage stone-forming substances naturally. By tailoring the diet to different BMI groups, the approach could be more personalized and effective, helping individuals manage their risk based on their unique body composition. This method could empower people with a proactive, manageable way to prevent kidney stones without relying heavily on medication.

What evidence suggests that this controlled diet could be effective for kidney stone prevention?

Research has shown that following a specific diet can help prevent kidney stones, particularly those made of calcium oxalate. Studies indicate that a balanced diet with adequate calcium and moderate oxalate can reduce the likelihood of stone formation. Previous research found that proper nutritional guidance can decrease signs of kidney stone formation and reduce recurrence. This trial will evaluate the effectiveness of a controlled diet across different BMI categories in managing kidney stone risk. Overall, diet plays a crucial role in managing the risk of developing kidney stones. ^{6 7 8 9 10}

Who Is on the Research Team?

Dean G Assimos, MD

Principal Investigator

University of Alabama at Birmingham

Are You a Good Fit for This Trial?

This trial is for adults aged 25-60 who are not obese (BMI <50) and have no history of kidney stones, diabetes, liver or renal diseases, bowel or other endocrine disorders. Pregnant women or those planning to become pregnant soon cannot participate.

Inclusion Criteria

Your Body Mass Index (BMI) is less than 50.

I am between 25 and 60 years old.

Exclusion Criteria

I have had kidney stones in the past.

I have a history of diabetes, liver, kidney, bowel diseases, or other hormone-related conditions.

My liver enzymes are abnormal.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Dietary Intervention

Participants are placed on a controlled low oxalate diet to estimate endogenous oxalate synthesis

12 days

Daily monitoring

Assessment

Participants receive oral doses of 13C2-glycolate and 13C6-vitamin C to determine conversion to 13C2-oxalate and assess body morphometric indices, oxidative stress, and insulin resistance

Concurrent with dietary intervention

Follow-up

Participants are monitored for safety and effectiveness after the dietary intervention

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Controlled Diet

Trial Overview The study is testing the impact of a controlled low oxalate diet on non-obese and obese individuals without kidney stones. The goal is to understand how obesity affects the body's production of oxalate, which could lead to new treatments for preventing kidney stones.

How Is the Trial Designed?

Group I: 20-24.9 BMI Active Control 1 Intervention

Participants with a BMI that falls between 20 and 24.9 who will receive the controlled diet

Group II: 25-29.9 BMI Active Control 1 Intervention

Participants with a BMI that falls between 25 and 29.9 who will receive the controlled diet

Group III: 30-34.9 BMI Active Control 1 Intervention

Participants with a BMI that falls between 30 and 34.9 who will receive the controlled diet

Group IV: 35-39.9 BMI Active Control 1 Intervention

Participants with a BMI that falls between 35 and 39.9 who will receive the controlled diet

Group V: 40-44.9 BMI Active Control 1 Intervention

Participants with a BMI that falls between 40 and 44.9 who will receive the controlled diet

Group VI: 45-50 BMI Active Control 1 Intervention

Participants with a BMI that falls between 45 and 50 who will receive the controlled diet.

Who Is Running the Clinical Trial?

University of Alabama at Birmingham

Lead Sponsor

Trials

1,677

Recruited

2,458,000+

Published Research Related to This Trial

In a study of 112 patients who received dietary recommendations to prevent kidney stones, patients recalled about 67% of the advice given, with better recall for key recommendations like increasing fluid intake and reducing meat consumption.

Patients who received fewer than four dietary recommendations had a higher recall rate (47% recalled all recommendations) compared to those given more than three, suggesting that simplifying dietary advice may improve patient adherence and understanding.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Factors associated with patient recall of individualized dietary recommendations for kidney stone prevention. Penniston, KL., Wertheim, ML., Nakada, SY., et al.[2018]

In a study of 57 patients with recurrent urolithiasis followed for 5 years, individualized dietary advice and pharmacological treatment led to significant reductions in urinary excretion of calcium, uric acid, and sodium.

The combination of these interventions also resulted in a significant decrease in the recurrence of kidney stones compared to pre-treatment levels, highlighting the effectiveness of tailored clinical therapy and nutrition in managing urolithiasis.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Influence of clinical therapy and nutritional counseling on the recurrence of urolithiasis. Damasio, PC., Amaro, CR., Padovani, CR., et al.[2019]

A combined nutritional and medical therapy approach significantly improved urinary risk factors for stone disease in 137 patients over an average follow-up of 14.39 months, with notable improvements in hypocitraturia (67% of patients), hypercalciuria (82%), and hyperuricosuria (72%).

The study highlights that individualized medical management based on specific urinary abnormalities can effectively reduce stone risk, especially for patients who do not respond to dietary changes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Patient-centered medical therapy for nephrolithiasis. Marchini, GS., Ortiz-Alvarado, O., Miyaoka, R., et al.[2013]

Diet plays a significant role in urinary stone disease, and personalized dietary modifications can help reduce the risk of stone formation by addressing individual urinary risk factors and dietary preferences.

The development of a new 40-item stone-specific food screener aims to provide a standardized tool for assessing dietary risk factors related to stone disease, although further validation is needed for its broader use in clinical settings.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Diet and Kidney Stones: The Ideal Questionnaire. Penniston, KL.[2022]

A DASH-style diet, which emphasizes fruits, vegetables, and low-fat dairy while reducing sodium and processed foods, is linked to a significant reduction in the risk of developing kidney stones, as shown in a study involving over 240,000 participants across three large health studies over up to 18 years.

Men and women with the highest DASH scores had relative risks of kidney stones that were 45-40% lower compared to those with the lowest scores, indicating that this diet may be particularly effective in preventing kidney stone formation, regardless of calcium intake.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

DASH-style diet associates with reduced risk for kidney stones. Taylor, EN., Fung, TT., Curhan, GC.[2022]

Nutritional factors play a significant role in the prevention of kidney stones, particularly calcium-containing and uric acid stones, and are often included in treatment plans for patients at risk.

The article emphasizes the importance of both general and tailored nutritional approaches to address specific risk factors for kidney stone formation, highlighting the need for assessing individual nutrition risks.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Diet and alternative therapies in the management of stone disease. Penniston, KL., Nakada, SY.[2012]

Dietary modifications can significantly reduce the risk of developing kidney stones (nephrolithiasis) for many patients, potentially eliminating the need for medication.

Key dietary recommendations for stone prevention include maintaining adequate fluid intake, consuming modest amounts of calcium, reducing sodium intake, and limiting animal protein, all of which are supported by practice guidelines.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Diet and Stone Disease in 2022. Dai, JC., Pearle, MS.[2022]

Patients with nephrolithiasis (kidney stones) showed higher body mass index and body fat percentage compared to controls, indicating a significant association between obesity and kidney stone formation.

The study found that nephrolithiasis patients had significantly higher oxalate intake than controls, and 30% of these patients exhibited hypercalciuria, suggesting that dietary management and obesity prevention are crucial in treating and preventing kidney stones.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Adequate dietary intake and nutritional status in patients with nephrolithiasis: new targets and objectives. Oliveira, LM., Hauschild, DB., Leite, Cde M., et al.[2014]

In a study of 242 patients with calcium-containing kidney stones, those who received specific dietary therapy tailored to their metabolic needs had a significantly lower recurrence rate of stones (6%) compared to those who followed general dietary advice (19%).

The results suggest that personalized dietary counseling is crucial for preventing future kidney stones, highlighting the importance of tailored interventions over generic recommendations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A prospective study of nonmedical prophylaxis after a first kidney stone. Kocvara, R., Plasgura, P., Petrík, A., et al.[2019]

Dietary advice alone did not significantly reduce urinary supersaturation in most patients with idiopathic calcium urolithiasis, but it did lower calcium oxalate and uric acid supersaturation in 19% of patients who complied well with the recommendations.

Effective dietary management requires a balanced focus on both increasing fluid intake to over 2,000 ml/day and reducing meat protein intake, as these factors are interconnected and crucial for lowering the risk of stone formation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of a 'common sense diet' on urinary composition and supersaturation in patients with idiopathic calcium urolithiasis. Hess, B., Mauron, H., Ackermann, D., et al.[2018]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC4525130/

Nutritional Management of Kidney Stones (Nephrolithiasis) Kidney stone prevention should be individualized in both its medical and dietary management, keeping in mind the specific risks involved for each type of stones ...

2. sciencedirect.com sciencedirect.com/science/article/abs/pii/S2173578625001623

Efficacy of dietary interventions targeting calcium and ... The results of this review suggest that a balanced diet with adequate calcium intake and moderate dietary oxalate control reduces the formation of calcium ...

3. cariguidelines.org cariguidelines.org/nutrition-therapy-for-the-prevention-of-kidney-stones/

Nutrition therapy for the prevention of kidney stones Retrospective studies of nutrition counselling demonstrate a decrease in markers of kidney stone formation (5) and decreased rates of stone recurrence (6, 7).

4. journals.plos.org journals.plos.org/plosone/article?id=10.1371/journal.pone.0250257

Effect of dietary treatment and fluid intake on the prevention of ... The results of this study indicate that water intake can reduce stone recurrence. Meanwhile low protein with or without fiber does not affect ...

5. frontiersin.org frontiersin.org/journals/nutrition/articles/10.3389/fnut.2025.1538289/full

Healthy dietary patterns, biological aging, and kidney stones Conclusion: These findings provide valuable insights into the complex interplay between dietary patterns, biological aging, and the risk of kidney stone.

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8229448/

Nutrition and Kidney Stone Disease - PMC A case-control study of 186 calcium oxalate stone patients found a significant positive association between dietary ascorbic acid intake and urinary oxalate ...

7. kidney.org kidney.org/kidney-topics/kidney-stone-diet-plan-and-prevention

Kidney Stone Diet Plan and Prevention Learn about managing kidney stones with a specialized diet. Discover the role of hydration, types of kidney stones, and dietary tips for prevention.

8. sciencedirect.com sciencedirect.com/science/article/pii/S2161831323002715

Review Kidney Stone Prevention These data consistently indicate that the high sodium intake increases risk of kidney stone formation, whereas sodium restriction is promising to prevent KSD.

9. aafp.org aafp.org/pubs/afp/issues/2011/1201/p1234.html

Treatment and Prevention of Kidney Stones: An Update Increased dietary fructose has been associated with up to a 38 percent higher risk of kidney stones. Increased fructose intake increases urinary ...

10. auanet.org auanet.org/guidelines-and-quality/guidelines/kidney-stones-medical-mangement-guideline

Kidney Stones: Medical Mangement Guideline The purpose of this guideline is to provide a clinical framework for the diagnosis, prevention and follow-up of adult patients with kidney stones.