Kidney stones are very sharp pain. If you've ever had calcium oxalate stones, you know that going through it can be a pretty unpleasant experience. And unfortunately, if you have had a kidney stone, you are more likely to have another. According to Harvard Health Publishing, about half of people who have kidney stones develop another within seven years if they don't do something to prevent it.
The good news is that your diet plays an important role in preventing kidney stones. If you have too much calcium oxalate in your urine, you can cause calcium oxalate kidney stones to form, the most common type of kidney stone. But if you limit the foods that cause calcium oxalate buildup, you can avoid future problems in the future.
What are calcium kidney stones?
Calcium kidney stones are hard, solid masses that form in the kidneys from high levels of calcium and oxalate in the urine. When you eat, your body breaks food down into smaller components. Some of the components are used for what your body needs them at the time, and others are left in the bloodstream as waste products in the form of hard crystals.
All of these crystallized waste products travel through the blood to the kidneys. Part of the kidneys' job is to filter these waste products and deposit them in your urine so you can flush them out of your body the next time you pee. Under normal circumstances, the kidneys can handle this job very well. However, if the concentration of waste products in the urine is too high, the crystals begin to stick together and form a solid, hard mass.
This mass becomes a kidney stone. In the case of calcium oxalate kidney stones, the concentration of oxalate in the urine is too high for the kidneys.
Why does oxalate rise?
There are two main reasons why the amount of oxalate crystals in the urine may be higher than normal. The first is that your diet is too high in oxalates, protein, sugar, and / or sodium . And the second is that there is not enough water in your body because you are dehydrated . If the volume of fluid in the kidneys decreases, this naturally increases the concentration of calcium oxalate, even if your diet is not rich in problem foods.
Fortunately, you have some control over these two factors. To reduce the chances of calcium oxalate in the urine and the eventual development of calcium kidney stones, you can change your diet and incorporate other important lifestyle changes.
3 ways to reduce the chance of having oxalate crystals
Avoid foods high in oxalate
If you have a large amount of calcium oxalate in your urine, reducing your intake of high oxalate foods and beverages can help reduce concentration. Examples of foods and beverages high in oxalate include:
- Walnuts
- Black tea
- Spinach
- Chard
- Okra
- Rhubarb
- Beet
- Sweet potatoes
- Cocoa
- Tofu
- Soy
In addition to limiting these foods, eating them with a source of calcium can help bind oxalate and reduce the risk of developing stones. The National Institute of Diabetes and Digestive and Kidney Diseases notes that increasing the amount of calcium-rich foods you eat overall can also be a good idea.
Eat more calcium
Although it seems contradictory to eat more calcium when kidney stones are made of calcium and oxalate, this mineral can help reduce your risk. Calcium binds to oxalate in the stomach and intestines before it reaches the kidneys. This process prevents the accumulation of oxalate in the kidneys and can actually reduce the risk of kidney stones.
Harvard Health Publishing says it's best to get calcium from food, rather than supplements, as some evidence shows that the high doses of calcium provided in supplements can increase your risk of stone development. As a general rule, most adults should aim for 1,000 milligrams of calcium per day (adult men over 50 need 1,200 milligrams). Dietary sources of calcium include:
- Yogurt
- Hard cheese
- Cottage cheese
- Sardines
- Milk
- Salmon
- Turnip greens
- Kale
- Chinese cabbage
Limit your protein intake
It can also be helpful to limit the amount of protein, especially animal protein, that you eat. Taking too much protein increases uric acid levels in the urine and reduces the amount of citrate, a compound that can help prevent stone formation. Together, these factors can increase your risk of developing kidney stones.
The main dietary sources of animal protein include:
- Cow meat
- Chicken
- Pork
- Viscera
- Eggs
- Fishes
Although you need to limit animal protein, you should still meet your protein recommendations for the day. The National Institute of Diabetes and Digestive and Kidney Diseases recommends replacing animal proteins with plant-based proteins, such as beans and lentils, which are high in protein but low in oxalates.
