Q: I have kidney (base and have been advised by the doctor.. and nurses not to eat fruits and vegetables as it will affect the potassium in my blood. Should I avoid all fruits and vegetables?
 

A: Because of your kidney disease, potassium may accumulate in your blood. If your potassium is normal, eat two servings each of a variety of fruits and vegetables. If your potassium is high, you should still eat  fruits and vegetables but avoid high potassium fruits and vegetable.. Some high potassium fruits are bananas, orange, durians, grapes and fruit juices, while high potassium vegetables include potato, kailan, spinach, pumpkin, tomato and celery. Wholegraln products can also be a high potassium source if eaten in large quantities. A more complete list of other high potassium fruits and vegetables and other foods is available from your dietitian.

Q: Is it  true that kidney patients cannot drink milk or eat tofu? What protein is best for me?

A: Protein is needed for building muscles, repairing body tissues and maintaining a strong immune system. Your body will break down the protein that you eat and absorb it, but there is a part of the protein that cannot be used and is found as waste products (such as urea) in your blood. When your kidneys are weak these waste products build up in your body. This can make you feel unwell. You may feel weak, tired and nauseous, loss your appetite and be short of breath.

Your body prefers to use protein from animal products, like meat, chicken, fish, eggs and milk products. Plant proteins like tofu, soymilk and lentils (dhal) will make more urea. If you are not vegetarian, aim for at least 70% of your protein to come from an animal source. Your dietitian will work with you to determine how much total protein you should eat, as excessive protein from any source will add more stress to your kidneys.

Plant proteins, along with milk products, are also high in phosphorus, which is a mineral that can cause your bones to loss calcium. Over time, this increases your risk of fractures and osteoporois. If your phosphorus is normal, follow the 70% rule as mentioned above. If your phosphors is high, it is best to avoid plant proteins and milk products, along with other high phosphorus foods, like malted drinks (e.g. Milo,  Ovaltine) and wholegrain products.

This issue's resident dietitian is Gladys Wong, Chief Dietitian at Alexandra Hospital.