Bananas are not poisonous. In fact, bananas are tropical fruits that contain many nutrients. A medium-size banana weighs about 126 grams and contains 450 milligrams of potassium, 0.5 milligrams of vitamin B6, 81 IU of vitamin A and 9 milligrams of vitamin C. A banana also provides 3 grams of dietary fiber.
Besides having nutritional dietary value, there are some health benefits associated with bananas. Including bananas in a diet may help with blood pressure, lower the chance of developing asthma and support heart health. Bananas may also help restore potassium in the body in people with diarrhea.
Although bananas have health benefits, there are some associated side effects which people who take certain medications should be aware. For example, people who use beta-blocker medication or have kidney problems should consume bananas in moderation to avoid an increase of potassium levels in the body.