Renal cell cancer (or kidney cancer) is cancer of the lining of tubules (or small tubes) within the kidney (renal cell adenocarcinoma). The kidneys are located on either side of the backbone, just above the waist. The kidney tubules are responsible for filtering and cleaning the blood, yet renal cancer impedes this process. When a patient suffers from renal cancer, some foods can also greatly affect the functioning of the kidneys.

This article suggests certain foods to avoid with renal cancer:

1. Dry fruits
Dry fruits should be avoided when a person is suffering from renal cancer. Dry fruits like raisins and dates are usually considered good to eat. The problem for renal cancer patients is that when these fruits are dried they end up having higher levels of potassium. Both sodium and potassium cannot be managed by the weak kidneys of a renal cancer patient, and food with these substances must be avoided.

2. Mayonnaise
Mayonnaise is a very popular spread for sandwiches and tasty too. However, it has a lot of calories. Just one spoonful can contain 100 calories. It is high in saturated fats and hence must be avoided.

3. Margarine
Margarine and butter are yet another popular spread for bread. Both these products are high in calories and saturated fat, both of which are not good for the kidneys.

4. Water
One must drink water to be healthy and hydrated but drinking too much water can be a problem. It can cause fluid retention and lead to swelling and other problems. Fluid consumption must be controlled and drinking excess fluids should be avoided.

5. Tomatoes
Tomatoes are popularly used in salads and other food preparation. For those who have renal cancer, tomato consumption must be restricted. The reason is that tomatoes have high potassium. Even consuming tomato sauce is not advisable as one cup can have nearly 1000mg of potassium, which can cause problems for the kidney.

6. Dairy products
Dairy products like milk, cheese, and yogurt are usually good for health. However, for those with renal cancer, it can cause problems since it is high in potassium, high in phosphorus, as well as rich in fat. This can cause problems leading to phosphorus accumulation in blood, thus weakening bones. Almond milk can be considered as an alternative.

7. Whole grains
Whole grains are always recommended over regular grains, since they are good for health. Whole wheat and brown rice are considered good for health. Both these foods have excess of potassium and phosphorus that are bad for renal cancer patients. Consumption must be avoided or limited to prevent problems.

8. Animal protein
While proteins are good, animal protein found in eggs, cheese, beef, pork, and chicken can cause accumulation of uric acid. This can cause complications like muscle weakness and heart problems. Food with plant protein should be preferred.

9. Potatoes
Potatoes, as well as sweet potatoes, are another popular vegetable people like. It also contains high potassium and hence must be avoided or double cooked to reduce its potassium levels.