Diet plays an integral role in treating cancer, a disease characterized by abnormal cells that multiply uncontrollably and destroy normal cells and tissue. Nonetheless, there are certain types of foods you need to avoid while receiving radiation treatment. Radiation kills or slows the growth of malignant cancer cells and tumors, an abnormal growth of cancerous tissue. Consult your doctor about your diet and what foods you should avoid while getting radiation.
Raw Fish and Shellfish
Raw fish and shellfish are especially dangerous to eat when you have cancer and are taking radiation treatment. Radiation kills healthy cells, reduces your immune strength and increases your susceptibility to infections. Raw fish and shellfish, including sushi, clams and oysters, are often contaminated with viruses, bacteria and parasites. Scientists at Mahidol University in Bangkok, Thailand, report that there is a significant presence of hepatitis A virus and bacterial contamination in raw oysters, according to research published in the "Southeast Asian Journal of Tropical Medicine and Public Health" in Jan 2010.
Unpeeled Fruits and Vegetables
Radiation creates toxins in your body that decrease your natural supply of the healthy bacteria and digestive enzymes you need to digest food. Unpeeled raw fruits and vegetables, such as strawberries and lettuce, contain bacteria that increase your risk of infections in your gastrointestinal tract. Instead, eat oranges, apples, tomatoes and cucumbers immediately after you scrub them with water and anti-bacterial soap and then peel off the skin. If eating raw fruits and vegetables gives you gas, then cook them instead. Fruits and vegetables are high-fiber foods that may be troublesome to digest and cause diarrhea.
Avoid eating foods that are fried or greasy. Fried foods are difficult to digest and frying increases the production of free radicals, substances that accelerate aging and the breakdown of cell membranes. The FDA reports that frying potatoes causes a cancer causing substance called acrylamide, which forms from sugars and asparagine, an amino acid present in the potato.
Spicy foods may taste good, but they can wreak havoc in your gastrointestinal tract. Radiation causes nausea and loose stools. Spicy foods can irritate your intestines and rectum and cause cramping and diarrhea. Instead, choose soft and bland foods, such as chicken and rice. Avoid adding salt or eating foods high in sodium since the mineral increases your blood pressure and causes you to retain water and toxins.
Other Foods To Avoid
If you receive radiation near the chest, throat or mouth you should also refrain from eating foods with certain textures, according to the National Cancer Institute. Foods that are crunchy or have sharp edges, such as chips and pretzels, should be avoided. Also avoid or limit foods high in acid -- tomatoes and citrus fruits -- foods high in sugar and drinks that contain alcohol. These foods may cause cuts or burns in your mouth or throat area.