There are many types of food toxicity. Some foods are inherently toxic in any conceivable form, some are toxic if they are not prepared correctly, some have certain parts that are toxic, and some are only toxic if eaten in large quantities. So, what is a person to do? It seems as if anything in excess is dangerous, so perhaps we don't think about items that are more toxic because of the information regarding "normal" foods and their toxicity that bombards us daily. The eight foods listed below are mixed bag of the aforementioned types of food toxicity.
8. Puffer Fish, AKA Fugu
I've included this food although it is not a commonly eaten food, particularly in America. Puffer Fish is commonly served in Japanese restaurants, but the chef preparing it must be specially trained because the liver and ovaries of the fish contain a neurotoxin that will kill a person, painfully and relatively quickly. A common practice in restaurants that serve Fugu is to have the customer ordering it sign a liability waiver before they are served. The fish is prepared correctly if the consumer's lips and tongue tingle and are slightly numb, but their lungs continue to be innervated enough to keep expanding. Two minutes after eating fugu, if the person is still alive, it was a successful dish! It makes me wonder if anything can actually taste so good that a person will risk death to partake in it. I think not. One interesting caveat to fugu: the emperor of Japan is not allowed to eat fugu in any form.
Mushrooms are a commonly known poisonous food. In truth, there is no harm in the mushrooms we purchase at the grocery store, but problems tend to arise when people decide to live off nature and collect wild mushrooms without knowing what types are benign and what types are toxic. The toadstools that are vibrantly colored are usually the toxic ones, but some of the boring brown ones are poisonous as well. The poison in mushrooms is a hepatotoxin that causes liver failure and eventual death to people who consume the poisonous types of mushrooms.
Cashews are technically a seed and not a nut, but they are toxic nonetheless. They are only toxic in their raw, unprocessed or uncooked form. Raw cashews sold in the grocery store are steamed, and therefore not actually raw and toxic. Urushiol is the toxin found in raw cashews. This is the same toxin found in poison ivy, and can cause fatal reactions inside the consumer's gastrointestinal tract.
Cherries are a healthy fruit, and contain many vitamins that are important to human nutrition. The cherry flesh itself is not toxic, but ingestion of the pits can be lethal. The cherry pits, if crushed or chewed release cyanide that is commonly known as toxic to humans. One crushed cherry pit will not kill you, but several pits will kill you. I don't think you want to find out exactly how many pits it takes for a fatality to occur, since it can differ from person to person. Scientists rate toxicity as LD 50, or the amount of a substance that is a lethal dose in 50% of the population. I am not sufficiently curious enough to see if I would be in the unlucky 50% if I ingested the LD-50 dose of cherry pit cyanide.
Almonds are also toxic if eaten before properly prepared. Like other seeds listed above, the seeds contain cyanide, which is a lethal poison and can build up in tissues over time, eventually causing a fatality. In most countries it is illegal to sell almonds that have not been treated by some heat source in order to rid it of the cyanide in its poisonous form.
3. Chili Peppers
Chili peppers are eaten in larger quantities by some cultures more than others. Even so, several chilse are not going to cause a lethal reaction in most people. However, if large quantities of chiles are eaten, the capsaicin contained in all chili peppers can be enough to kill the consumer. The hotter the chili, the higher the level of capsaicin in the pepper. It is the capsaicin that is responsible for the burning and heat the chili pepper imparts to recipes and even skin. Capsaicin is a strong chemical and is used commonly in pepper spray by law enforcement, and also found in paint thinner.
The leaves and stems of potatoes are poisonous, but the potatoes themselves can also be poisonous as well. Any time you see a green potato, it contains the poison found in the leaves and stems called glycoalkaloid. Occasionally eating a green potato will not kill you, but don't make a habit of it. Throw away potatoes with green skin, eyes or spots, as these are poisonous areas of the tuber.
Yes, surprisingly water is toxic. I'm not talking about polluted water, because that is obviously unhealthy. I mean plain water in vast quantities. This is one of the items that is necessary for human survival, but too much of it can be fatal. Too much water will dilute all of the necessary nutrients and chemicals in the bodily fluids and tissues. In terms of water, time is the key. Water can be consumed over time in quantities, but in too short of a period of time, the water will dilute necessary factors for metabolic functions.