As much as diet causes kidney stones, diet change prevents them.
Not diet in general, of course, too vague to matter.
Thus far decent science identifies only seven components of diet as affecting stone formation: calcium, sodium, refined sugars, potassium, protein, oxalate and high fluids of the proper kinds.
A diet correct for the first five components corresponds with present day healthy diet recommendations for all people in the US. Everyone should eat it. Oxalate control and high fluids are specific to stones, however, so all seven components combined is properly named the “kidney stone diet”.
The featured picture shows a new collection of recipes by Melanie Betz that address, excluding fluids, all components of the kidney stone diet. It is well enough to tell patients what a correct diet contains, but quite another to give recipes for actual foods that do the work of it. Here is the link to get the recipes.
I will say something about Melanie later on in this article, but first a review of the diet to provide a perspective on what she has given us.
The Kidney Stone Diet
The US population eats too little calcium for ideal bone health. Because of idiopathic hypercalciuria and probably other factors not as well established, stone formers have an abnormally high risk of bone mineral loss and fractures. So adequate diet calcium is especially important, above 1000 mg per day or more.
Most kidney stones contain calcium oxalate, and oxalate absorption is reduced by high calcium intake. The powerful effect of high diet calcium to lower urine oxalate and prevent calcium oxalate kidney stones is seen in the one diet based stone prevention trial.
Because urine calcium tracks with sodium, lowering diet sodium below the US “tolerable upper limit” of 100 mEq (2300 mg) per day, ideally below 65 mEq (1500 mg) per day, can prevent high diet calcium from increasing urine calcium and stone risk. In fact, the combination of low diet sodium with high diet calcium was the only one that produced positive bone mineral balance among menopausal women.
Refined sugar is a world menace. One half of the molecule is fructose, metabolized directly to fat and capable of inducing insulin resistance in healthy people over as little as 8 weeks. After a dose of sugar, fructose or glucose, urine calcium rises and volume falls, so stone risk rises – all this within a hour or so. Your chocolate bar in mid afternoon is risky! Nationally, sugar is a main cause of obesity and diabetes. Stone formers need to limit it, and so does everyone else. I have – as best I can.
Skilled scientists have debated if protein excess reduces bone mineral, but all agree it raises urine calcium. Not the commonplace 0.8-1 gm per kg body weight per day recommended for all US people, but values much above that range.
Food potassium parallels food anions that when metabolized produce alkali. Good for bones, alkali also signals kidneys to release filtered citrate into the urine where it inhibits formation and growth of stone crystals. Low urine citrate is a recognized stone risk, and before adding potassium citrate supplements one should certainly bring diet potassium up to the US recommendations in hopes that will remedy at least part of the deficit, leaving less for expensive and unpleasant capsules of potassium citrate powder. We generally eat much less than the recommended 120 mEq (4700 mg) per day of diet potassium.
Even high calcium diet will not protect calcium oxalate stone formers against excessive oxalate intakes, so moderation is very important. This site has massive oxalate lists, and our article on low oxalate diet is perhaps the most popular of the over 100 articles here. I have inveighed against a compulsive search for every mg of oxalate in food. It overly constrains diet choices. But diet oxalate matters a lot when stones are calcium oxalate and 24 hour urine oxalate is high enough to convey risk of stone despite that diet calcium has been raised to the US normal range. For this reason, recipes for stone formers need to address oxalate excess.
What They Are
Melanie’s collection includes 4 appetizers, 7 breakfast items, 3 soups, 7 salads and dressings, 7 entrees, and 3 desserts. Her recipes meet all requirements of the kidney stone prevention diet but focus specially on dairy products – the main source of calcium. Seeing patients struggle to meet the requirement of 3 servings of dairy per day, she sought unique ideas for incorporating it into a dish rather than a simple glass of milk on the side.
Each recipe comes with the expected ingredient list for shopping, preparation instructions, and hints for serving. A professional Registered Dietitian certified in kidney nutrition, Melanie has carefully defined what a portion is and has analyzed portions for nutritional content, so calories, sodium, calcium, oxalate, and other nutrients can be counted.
She created all of the recipes, tested them, and made up her collection all by hand without any help. It is a downloaded PDF. She asks we pay for it given her time and effort in doing all the work of the foods themselves and making up the book. I never endorse products for sale except when they seem of unique potential value and reasonably priced, as here.
My Judgement of Them
Unknown as yet.
Thirty one recipes all aligned with kidney stone prevention is a trove to take notice of. They are a start, some real entries on a blank slate.
But I have not eaten them, nor made them myself – a metaphor as I do not cook – though they look attractive and seem enjoyable – on the page, at least.
Melanie tells me her husband, Eric, likes them, especially the Mac and Cheese and Burrito Bowl. She most likes the blueberry Panna Cotta dessert.
Your Judgment of Them
You will say if they matter.
Do you like them? Your family, will they happily eat them? Do you find them delicious, or at least acceptable? How hard are they to use? Are they a help in reality or just an ideal too difficult for a busy world. Given what they added to your stone prevention, is the price a fair price?
Please comment on the article. Without your feedback, how can Melanie know what to do beyond what she has done? How can I know if I am right in putting her recipe collection forward as useful. Melanie and I look forward to your comments.
Because of her training I know the recipes accord with the goals of the kidney stone diet. Her knowledge is sound.
But food is in the eating.
Melanie As Colleague
Melanie works in the Nephrology Section as our dietitian, so is part of our team. Her high level of credentials outlined in her recipe collection, and her 10 years of experience are why we recruited her.
She mainly cares for kidney disease patients in whom an error of diet can be dangerous. Many require dialysis, or have such impaired kidney function that diet is a fine balance between nutrition and the need to limit sodium, and potassium, and protein.
Melanie has counseled a number of our kidney stone patients, and I believe that led her to create these recipes. She is a fine clinician.
Since age 3, Melanie has cooked, she told me, and she is a foodie. Monthly, she organizes a group of 6 women friends who choose a new ethnic restaurant and eat there to sample the cuisine.
Being at a university she has begun doing research, and I have had the pleasure of collaborating a bit with her.