Avoid Eating Too Many Tomatoes If You Have This Medical Condition
You find them in salads, sandwiches, pizzas, curries, and pastas. Tomatoes are a staple in most households, mainly because of their nutritional benefits and also owing to their sweet and sour flavor, which adds so much to a dish.
For most people, tomatoes are a healthy vegetable you'd strive to consume more of. They pack a punch when it comes to calcium, vitamin C, potassium, folate, vitamin K, and beta-carotene. They're great when it comes to protecting your skin from sun damage, strengthening and repairing your bones, reducing cholesterol and blood pressure levels, supporting eye health, and reducing your risk of certain cancers. But even generally healthy foods can be problematic for someone who's on a diet to manage a certain medical condition. In the case of tomatoes, that would be people with impaired kidney function and chronic kidney disease (CKD). Renal dietitians might put tomatoes on the list of foods you should be mindful of, but they would also tell you that the real concern is specifically with eating too many tomatoes.
Why too many tomatoes could be problematic for chronic kidney disease
It's the same reason why you should avoid eating avocados for kidney health: tomatoes contain a lot of potassium. Even though your body needs potassium for optimal function of your muscles, nerves, and heart, for those with chronic kidney disease, your kidneys don't function as well as they're supposed to. This means that they're unable to remove excess potassium from your blood, which can lead to a buildup of the mineral in your system. This is called hyperkalemia, and it usually occurs in the later stages of kidney disease.
Too much potassium in your system can manifest as muscle weakness, numbness, and tingling, or it can be as severe as heart palpitations, difficulty breathing, chest pain, nausea, and vomiting, depending on just how much of the mineral is in your system. It can even lead to a heart attack.
For someone with chronic kidney disease, special attention is usually placed on potassium, sodium, and phosphorus levels. That being said, potassium becomes a concern with kidney impairment only if your doctor detects high potassium levels in your system. In other words, a low-potassium diet might not even be necessary for those in the first to third stages of chronic kidney disease. Dietitians often offer basic steps to follow when it comes to the consumption of tomatoes and other potassium-rich foods if you have kidney disease.
How to include tomatoes (safely) in a renal diet
While it's always good to check with your dietitian about foods to eat and foods to avoid for kidney health, there are some general principles that have been laid out by experts for people with this medical condition.
For starters, your potassium levels become a concern only when the mineral builds up in your system. In other words, it is unlikely that you have to think about tomatoes during the early stages of kidney disease. However, according to Laura Kyte, a renal dietitian at Royal Devon and Exeter NHS Trust, even if you've been asked to lower your potassium intake, there are ways to incorporate tomatoes into your diet, provided you're paying attention to portion size, what form you're consuming them in, how often you have them, and what foods you're combining them with (via Kidney Care U.K.). For example, having small portions with one meal a day or a few times a week, avoiding higher concentrations of the stuff like tomato juice or tomato purée, and looking at your entire meal to make sure you're not adding any more potassium-rich foods with the tomatoes are all good steps to follow. But again, these tips would have to be tweaked based on your own particular potassium levels and your dietitian's advice.
It might also be worthwhile to stock up on other lower-potassium alternatives to tomatoes, like cucumber, grated carrot, sliced mixed peppers, lettuce, sliced onions, or rocket.