Most everyone admits that they don’t eat enough fruits and vegetables, but before you start trying to increase your daily intake, there are a few things you should know—especially if you like to grow-your-own food or if you're a start-from-scratch cook. Some of the healthiest vegetables have relatives that could kill you.
Seeds, Pits & Kernels
The unsavory seeds, pits, and kernels of some of our favorite fruits and vegetables contain a naturally occurring substance called amygdalin, which in large amounts can be fatal since amygdaline can turn into hydrogen cyanide. Apples, pears, mangoes, peaches, and apricots, all contain this chemical, but don’t worry: Accidental swallowing or the occasional ingestion is not dangerous since the amount needed to induce a reaction is very high.
Another common toxin found in our kitchens includes potatoes that have turned green. Solanine, a natural glycoalkaloid, can occur when potatoes are exposed to too much light. The green color just under the skin strongly suggests that toxic build-up may have occurred. If you notice a slight green layer just under the potato skin, cut away the green portions of the potato skin before cooking and eating. There is no need to discard your favorite tuber since the non-green portion is safe to eat. It is recommended not to consume potatoes with a bright green layer just under the potato’s skin since it may cause headache, nausea, fatigue and GI issues. You can avoid this problem by storing potatoes in a dark, cool, dry place.
Raw Red Kidney Beans
Raw, uncooked, almost impossible to eat, and certainly not very tasty, red kidney beans, contain a natural toxins called lectins. With many Americans converting to a more unprocessed or “raw” diet, it's important for the home cook to soak red kidney beans in water for at least five hours before cooking. Eating as few as four or five raw beans can cause symptoms which are usually marked by extreme nausea, vomiting, and upset stomach.
If you are an adventurous gardener, be aware that rhubarb leaves are not the healthy, bitter green you might assume. There is a reason that rhubarb sold in your grocery store is sold without its leaves. Rhubarb leaves contain dangerously high levels of oxalic acid which can cause serious kidney damage potentially leading to death. Even though a 140-pound person would need to eat about 10 pounds of rhubarb leaves to die, a small amount still has the ability to make a person sick. When you're making a salad with fresh greens from your garden, steer clear of rhubarb leaves.
One of the most consumed carbohydrates in the world, cassava, contains naturally occurring cyanogenic glycosides. Also known as yucca, this starchy tuber must always be dried, soaked, and cooked properly. In Africa, improperly processed cassava is a major problem and is associated with a number health disorders, particularly among people who are already malnourished. The toxin is primarily found in the leaves which protects it from being eaten by insects or animals, but the roots still contain a significant amount of natural poison and long-term exposure to this raw food can lead to deadly consequences. The proper processing of cassava includes drying, soaking in water, rinsing or cooking very soon after it is harvested.
Most people know that many varieties if mushrooms are toxic. This does not include cultivated wild mushrooms that you find at the grocery store. The problem is that there is no easy way to distinguish a poisonous from nonpoisonous wild mushroom. Plus, you can't make toxic mushrooms nontoxic by cooking, canning, freezing, or any other means of processing. The only way to avoid mushroom poisoning is to not eat wild mushrooms.