What is a kidney stone?
A kidney stone is a hard object that is made from chemicals in the urine. Urine has various wastes dissolved in it. When there is too much waste in too little liquid, crystals begin to form. The crystals attract other elements and join together to form a solid that will get larger unless it is passed out of the body with the urine. Usually, these chemicals are eliminated in the urine by the body's master chemist: the kidney.
The stone-forming chemicals are calcium, oxalate, urate, cystine, xanthine, and phosphate.
After it is formed, the stone may stay in the kidney or travel down the urinary tract into the ureter. Sometimes, tiny stones move out of the body in the urine without causing too much pain. But stones that don't move may cause a back-up of urine in the kidney, ureter, the bladder, or the urethra. This is what causes the pain.
Possible causes include drinking too little water, exercise (too much or too little), obesity, weight loss surgery, or eating food with too much salt or sugar. Infections and family history might be important in some people. Eating too much fructose correlates with increasing risk of developing a kidney stone. Fructose can be found in table sugar and high fructose corn syrup.
Here are the top 5 kidney stone prevention tips:
- It's Not Just the Oxalate. Oxalate is naturally found in many foods, including fruits and vegetables, nuts and seeds, grains, legumes, and even chocolate and tea. Some examples of foods that contain high levels of oxalate include: peanuts, rhubarb, spinach, beets, chocolate and sweet potatoes. Moderating intake of these foods may be beneficial for people who form calcium oxalate stones, the leading type of kidney stones. A common misconception is that cutting the oxalate-rich foods in your diet alone will reduce the likelihood of forming calcium oxalate kidney stones. While in theory this might be true, this approach isn't smart from an overall health perspective. Most kidney stones are formed when oxalate binds to calcium while urine is produced by the kidneys.
Instead: Eat and drink calcium and oxalate-rich foods together during a meal. In doing so, oxalate and calcium are more likely to bind to one another in the stomach and intestines before the kidneys begin processing, making it less likely those kidney stones will form.
- Calcium is Not the Enemy. But it tends to get a bad rap! Most likely due to its name and composition, many are under the impression that calcium is the main culprit in calcium-oxalate stones. A diet low in calcium actually increases one's risk of developing kidney stones.
Instead: Don't reduce the calcium. Work to cut back on the sodium in your diet and to pair calcium-rich foods with oxalate-rich foods.
- It's Not One and Done. Passing a kidney stone is often described as one of the most painful experiences a person can have, but unfortunately, it's not always a one-time event. Studies have shown that having even one stone greatly increases your chances of having another.
Instead: Take action! Without the right medications and diet adjustments, stones can come back, and recurring kidney stones also could be an indicator of other problems, including kidney disease.
- When Life Hands You Kidney Stones… don't fret, It's important to consider dietary remedies alongside prescription medications. While it may seem easier to just take a pill to fix a medical problem, consider what lifestyle changes will also make a big impact on your health.
Instead: Chronic kidney stones are often treated with potassium citrate, but studies have shown that limeade, lemonade and other fruits and juices high in natural citrate offers the same stone-preventing benefits. Beware of the sugar, though, because it can increase kidney stone risk. Instead, buy sugar-free lemonade, or make your own by mixing lime or lemon juice with water and using a sugar substitute if needed. Also, some evidence suggests that citrate may prevent crystals that are already present from binding with each other, thus preventing them from getting bigger.
- Not All Stones are Created Equal. In addition to calcium oxalate stones, another common type of kidney stones is uric acid stones. Red meat, organ meats, and shellfish have high concentrations of a natural chemical compound known as purines. "High purine intake leads to a higher production of uric acid and produces a larger acid load for the kidneys to excrete. Higher uric acid excretion leads to lower overall urine pH, which means the urine is more acidic. The high acid concentration of the urine makes it easier for uric acid stones to form.
Instead: To prevent uric acid stones, cut down on high-purine foods such as red meat, organ meats, and shellfish, and follow a healthy diet that contains mostly vegetables and fruits, whole grains, and low fat dairy products. Limit sugar-sweetened foods and drinks, especially those that contain high fructose corn syrup. Limit alcohol because it can increase uric acid levels in the blood and avoid crash diets for the same reason. Eating less animal-based protein and eating more fruits and vegetables will help decrease urine acidity and this will help reduce the chance for stone formation.