By Dr. Mercola
Kidney stones will impact one in 10 people at some point during their lives, and this incidence is steadily increasing.
Each year, more than half a million people go to emergency rooms due to kidney stones,1 as, even though they most often pass without damage, they can quickly cause extreme pain.
What is becoming increasingly clear is that kidney stones are closely linked to lifestyle choices.
In fact, while only about 25 percent of kidney stones occur in those with a family history of them, making genetics only a small contributing factor, other lifestyle-associated conditions like high blood pressure, diabetes, and obesity are known to raise your risk.
New research has also strengthened this connection, showing that your diet and exercise habits can significantly influence your kidney stone risk.
Exercise, Avoiding Overeating May Lower Your Risk of Kidney Stones
In a study involving more than 84,000 postmenopausal women, it was found that those who exercised had up to a 31 percent lower risk of kidney stones.2 The link persisted even with only small amounts of physical activity.
Specifically, the research showed a lower risk from three hours a week of walking, four hours of light gardening or just one hour of moderate jogging. Diet-wise, women who ate more than 2,200 calories per day increased their risk of kidney stones by up to 42 percent, while obesity also raised the risk.
It should be noted that even though obesity increases kidney stone risk, weight loss surgery that alters your digestive tract actually makes them more common as well. After weight loss surgery, levels of oxalate are typically much higher (oxalate is the most common type of kidney stone crystal).
What Are Kidney Stones?
Kidney stones form when minerals in your urine crystallize, forming a "stone." Typically, compounds in your urine inhibit these crystals from forming. Some people form stones when their urine contains more crystal-forming substances, such as calcium and uric acid, than the available fluid can dilute. This can happen when your urine is highly acid or highly alkaline.
The conditions allowing kidney stones to form are created by problems in the way your body absorbs and eliminates calcium and other substances.
Sometimes, the underlying cause is a metabolic disorder or kidney disease, although certain drugs, such as Lasix (furosemide), Topomax (topiramate), and Xenical, can also promote kidney stones. Many times, it is a combination of factors that creates an environment favorable to stone formation.
According to the National Kidney Foundation:3
"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. In most people, having enough liquid washes them out or other chemicals in urine stop a stone from forming. The stone-forming chemicals are calcium, oxalate, urate, cystine, xanthine, and phosphate."
What Are the Signs of Kidney Stones… and Should You Seek Medical Help?
If your kidney stone is very small, it may pass out of your body without your noticing. But if the stone is large enough to cause irritation or blockage in your urinary tract, it will generally cause severe pain. Severe pain around your lower back is usually one of the primary signs of a kidney stone, but other symptoms also include:
- Persistent abdominal or side pain
- Blood in your urine
- Nausea or vomiting
- Fever and chills
- Foul-smelling or cloudy urine
If you suspect you have a kidney stone, you should seek medical help – even though treatment may not be required. Kidney stones can range in size from a grain of sand to larger than a golf ball, and if a stone fails to pass, permanent damage to your urinary tract can result.
So this is not something to ignore – not that you could easily ignore such a painful episode – but in most cases the best solution is letting the stone pass on its own. This might take days or even weeks in some cases, but the key is to drink enough pure water – NOT soda or fruit juice – to decrease the concentration of solids in your urine to the point that the stone will be dissolved.
Most kidney stones will pass on their own without medical intervention, but in some cases, such as if a stone blocks the flow of urine, damages kidney tissues, or is simply too large to pass on its own, you may need more aggressive treatment.
There are several medical procedures and surgical techniques that can be used to treat kidney stones, but the risks are high enough that physicians typically shy away from them, unless there's no other choice. Fortunately, there are now some more advanced options other than surgery, such as extracorporeal shockwave lithotripsy. This treatment entails being submerged in a tub of water where sound waves traveling through the liquid shatter the stones. They then pass as gravel through your urine in a few days or weeks.
You Can Drastically Lower Your Risk of This Painful Condition
Once you have had one kidney stone attack, your chance of recurrence is high, perhaps more than 50 percent. So, as with most health conditions, prevention is the best route of attack for kidney stones. Fortunately, there's much you can do toward this end, as many of the primary causes are linked to lifestyle choices. As The National Kidney Foundation reported:4
"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. These are the usual causes in most people."
5 Lifestyle Strategies to Reduce Your Kidney Stone Risk
Kidney stones can be excruciatingly painful and they also increase your risk of developing chronic kidney disease. The good news is that there's plenty you can do to reduce your risk…
- Drink Plenty of Water
The number one risk factor for kidney stones is not drinking enough water. If you aren't drinking enough, your urine will have higher concentrations of substances that can form stones. The National Kidney Foundation recommends drinking more than 12 glasses of water a day, but a simpler way to know if you are drinking enough water is to check the color of your urine; you want your urine to be a very light, pale yellow.
Every person's water requirement is different, depending on your particular system and activity level, but simply keeping your urine light yellow will go a long way toward preventing kidney stones. Remember to increase your water intake whenever you increase your activity and when you're in a warmer climate.
If you happen to be taking any multivitamins or B supplements that contain vitamin B2 (riboflavin), the color of your urine will be a very bright, nearly fluorescent yellow and this will not allow you to use the color of your urine as a guide to how well you are hydrated.
- Make Sure You Get Adequate Magnesium
Magnesium is responsible for more than 300 biochemical reactions in your body, and deficiency of this mineral has been linked to kidney stones. It also plays an important role in your body's absorption and assimilation of calcium, as if you consume too much calcium without adequate magnesium, the excess calcium can actually become toxic and contribute to health conditions like kidney stones.
Magnesium helps prevent calcium from combining with oxalate, which is the most common type of kidney stone.
Green leafy vegetables like spinach and Swiss chard are excellent sources of magnesium, and one of the simplest ways to make sure you're consuming enough of these is by juicing your vegetables. Vegetable juice is an excellent source of magnesium, as are some beans, nuts like almonds, and seeds, pumpkin seeds, sunflower seeds, and sesame seeds. Avocadoes are also a good source. These foods are also high in potassium, which will normalize your sodium/potassium ratio and also help.
- Avoid Sugar, Including Fructose and Soda
A diet high in sugar can set you up for kidney stones, since sugar upsets the mineral relationships in your body by interfering with calcium and magnesium absorption. The consumption of unhealthy sugars and soda by children is a large factor in why children as young as age 5 or 6 are now developing kidney stones.
One South African study5 found that drinking soda exacerbates conditions in your urine that lead to formation of calcium oxalate kidney stone problems. Sugar can also increase kidney size and produce pathological changes in your kidney, such as the formation of kidney stones. According to The National Kidney Foundation, you should pay particular attention to keeping your fructose levels under control:6
"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. In some individuals, fructose can be metabolized into oxalate."
You're more prone to kidney stones if you're bedridden or very sedentary for a long period of time, partly because limited activity can cause your bones to release more calcium. Exercise will also help you to resolve high blood pressure, a condition that doubles your risk for kidney stones. As the featured study found, even low amounts of exercise may be beneficial to reducing your risk.
You can find my comprehensive exercise recommendations, including how to perform highly recommended high-intensity interval training (HIIT), here.
- Eat Calcium-Rich Foods (But Be Careful with Supplements)
In the past, kidney stone sufferers have been warned to avoid foods high in calcium, as calcium is a major component of the majority of kidney stones. However, there is now evidence that avoiding calcium may do more harm than good. The Harvard School of Public Health conducted a study of more than 45,000 men,7 and the men who had diets rich in calcium had a one-third lower risk of kidney stones than those with lower calcium diets.
It turns out that a diet rich in calcium actually blocks a chemical action that causes the formation of the stones. It binds with oxalates (from foods) in your intestine, which then prevents both from being absorbed into your blood and later transferred to your kidneys. But be careful to avoid calcium supplements; it is best to get your calcium from calcium-rich foods.
So, urinary oxalates may be more important to formation of calcium-oxalate kidney stone crystals than is urinary calcium. It is important to note that it is the calcium from foods that is beneficial – not calcium supplements, which have actually been found to increase your risk of kidney stones by 20 percent.8 Check out my nutrition plan for a simple, step-by-step guide for what types of foods to eat to reduce your risk of kidney stones and other chronic and acute health conditions.