Forbidden Foods Generally, if you would eat a food, you can give it to your rats. Here are some exceptions and notables: raw dry beans or peanutsâcontains antinutrients that destroy vitamin A and enzymes needed to digest protein and starches, and causes red blood cells to clump. Roasted peanuts are fine. raw sweet potatoâcontains compounds that form cyanide in the stomach. Canned sweet potato is cooked and is fine. green bananasâinhibits starch-digesting enzymes green potato skin and eyesâcontain solanine, a toxin wild insectsâcan carry internal parasites and diseases raw bulk tofuâcan contain bacteria; packaged raw tofu is safe orange juiceâforbidden for male rats only, d-limonene in the skin oil, which gets into the orange juice during squeezing, can cause kidney damage and kidney cancer due to a protein that only male rats have in their kidneys. Pieces of the orange fruit are okay if you wash the orange-skin oil off of it after peeling it. Foods to Feed with Caution carbonated beveragesârats canât burp (but they can fart!) Dried corn can contain high levels of fungal contaminates which has been shown to cause liver cancer in rats. Corn also contains high levels of both nitrates and amines. These two compounds can combine in the stomach to form nitrosamines which are carcinogenic. Other foods high in nitrates include beets, celery, eggplant, lettuce, cucumber, radishes, spinach, collards and turnip greens. Therefore, I suggest you limit the amount of these foods in your ratâs diet. Some fresh corn is fine, but if you feed your rats blocks, try to avoid brands which have corn as the first ingredient. Mold Warning Spoiled or moldy food can contain deadly toxins. Never give nuts, grains, vegies or other food that looks or smells odd or spoiled. Donât buy too much food ahead. Molds can grow even in sealed plastic bags. When cutting up veggies, cut off the dried part that has been exposed from previous cutting and throw it away. If you see mold growing on a food, throw the whole thing away. Do not attempt to cut away the moldy section. Invisible mold filaments penetrate deep into the food. Pesticides on Produce The Environmental Working Group compiled the following information from FDA and EPA data. On average, rinsing with water will remove about one third of surface pesticides. Using soap, scrubbing, or peeling will further reduce the pesticide levels. Many pesticides, however, are absorbed by the plant or penetrate the surface of the fruit or vegetable. Where peeling is feasible, such as with apples and peaches, you end up throwing out some of the nutrients with the peel (although rats tend not to eat the peel anyway.) In the US, the produce with the most and most toxic pesticides are: strawberries, bell peppers, spinach, cherries, peaches, cantaloupe grown in Mexico, celery, apples, apricots, green beans, grapes grown in Chile, and cucumbers. To avoid pesticides, itâs a good idea to avoid these commercially grown foods, or at least limit them in your ratâs (and your) diet. Buy organic versions instead. To avoid foreign cantaloupe and grapes, only buy these items from May-December when they are in season here in the US. If you are feeding your rats my homemade rat diet, in the winter and spring buy watermelon instead of cantaloupe, or give another type of fruit, and give raisins instead of grapes. The produce with the least pesticides are: avocados, corn, onions, sweet potatoes, cauliflower, Brussels sprouts, grapes grown in the US, bananas, plums, green onions, watermelon, and broccoli. Toxic Water One source of toxins thatâs often overlooked is tap water. If your tap water is fluorinated, DO NOT give it to your rats! Fluorine can cause brain damage in rats. Instead give them bottled water, but investigate the quality of the brand you choose. Some bottled waters are nothing more than tap water and some contain fluoride! Chlorine is also toxic (there is evidence that chlorinated water raises the risk of miscarriage in women in the first trimester!) If your tap water is chlorinated, buy a filter that removes chlorine (such as Britta or Pur) and only give your rats filtered water. Even if your tap water comes from a well, lead leaches into the water from some pipes and all faucets. To reduce the amount of lead, run the water for a while, preferable until it becomes cold, which means itâs coming straight from the well, before filling your ratsâ water bottles. Never use hot water from the tap for cooking or drinking because hot water contains more lead. Itâs a good idea to clean the water bottle out with a bottle brush every few days. Use a tiny brush or cotton swab to clean the sipper tube. You should also keep track of the level in the bottle so you can make sure your rats are getting water. Sometimes, the ball bearing in the sipper tube gets stuck and blocks the flow of water. I like glass water bottles better than plastic ones because some plastics can leach into the water. Hard plastic bottles are better than soft ones. Low Sodium Diet For certain health problems, notably congestive heart failure, a low sodium diet will be beneficial. The best low sodium diet is rat blocks. Fresh fruits and vegies are okay, but donât give any canned foods. Check the label on frozen foods and only use those that do not list salt as an ingredient. Donât give any dairy products, baked goods, processed cereals or foods, or salted foods. Give distilled water only.