For most of us eating five servings a day of fruits and vegetables is lifesaving. But for some health issues the very thing we eat for good health could be making us ill. Grapefruit juice comes to mind as it interferes with statins and some other medicines.
Avocados-If you have a latex allergy, you should avoid avocados, kiwi and bananas.
Bananas can also mess with people who have kidney problems, likewise beets have a bad effect too.
Sprouts-If you are taking the anticoagulant drug, Warfarin, then sprouts should be avoided. Likewise other leafy green vegetables as they are full of vitamin K and that will mess with the anticoagulant.
Raw cabbage, along with broccoli, cauliflower and kale, are not recommended if you have issues with your thyroid. As they can block the hormone thyroxine.
Cherry pits and Apricot pits contain a chemical compound not unlike the poison cyanide. While eating one by accident may not kill you, it can make you ill.