10 Foods You Should Never Eat Raw

Raw beans contain proteins called lectins that break down with cooking. Not all lectins are toxic; some are even beneficial. The lectin in kidney beans, though — called phytohemagglutinin — is harmful at high doses [source: Andrews]. There are other beans that contain phytohemagglutinin, but red kidney beans contain them in the highest concentration by far [source: Medic8]. And when it comes to lectin, it's all about dosage.

Just a handful of raw kidney beans is enough to cause gastrointestinal problems like nausea and vomiting. The more you eat, the more intense your symptoms will be. Some folks have even been hospitalized with red kidney bean poisoning [source: Medic8].

You don't have to give up your red beans and rice just yet. To destroy the lectins in kidney beans, you just need to soak, drain and cook them thoroughly on the stovetop. Stovetop cooking reaches higher temperatures than a slow cooker, and kidney beans really do need to be boiled to be completely safe. To prepare dry kidney beans safely, soak for at least five hours, drain and rinse, then boil for at least 30 minutes on the stove [source: FDA].

The almonds we usually see in stores are known as sweet almonds, but their close cousin — the bitter almond — contains dangerous levels of hydrogen cyanide. Bitter almonds aren't very common in the U.S. but in Europe many chefs love them [source: Karp].

Children who ingest just a few raw bitter almonds are at risk of death. As few as 50 or fewer could kill an adult. Hydrogen cyanide poisoning includes symptoms from dizziness and headache to vomiting and convulsions, depending on how much you've eaten [source: Chaouali].

As with all of the foods on this list, proper cooking is the key to making bitter almonds safe to ingest. Blanching or roasting destroys the hydrogen cyanide in bitter almonds, but there doesn't seem to be any solid research on what temperatures you need to reach or for how long. If you're planning to cook with bitter almonds, your best bet is to follow a tried-and-true recipe.

Have you ever wondered why raw foodies don't eat potatoes? It's not because of an aversion to carbs; it's for safety reasons. Raw potatoes are potentially toxic because of a compound called solanine [source: MedlinePlus].

Not every potato contains enough solanine to be deadly, but the risk is high enough that it's not really worth taking. In general, green potatoes — even ones just a little green near the skin — or ones that are starting to sprout eyes have a higher solanine content. Symptoms of potato poisoning include stomach pain, headache and paralysis. Potatoes with the highest concentration of solanine will have some green discoloration when you cut into them and should be tossed [source: MedlinePlus]

Even if a raw potato doesn't contain much solanine, you're still better off cooking it before eating it. Uncooked potatoes also contain resistant starch. While some resistant starch can be good for your gut, the amount in raw potatoes is enough to give most people unpleasant side effects like severe gas and bloating [source: Blonz].

Cooking potatoes properly isn't hard. Roast, mash, boil or even grill them, and you won't have to worry about any of these things. Plus they taste way better.

People eat both the leaves and roots of the taro plant, but you never eat them raw. Think of taro root as the potato's healthier cousin. It has more fiber than a potato and is a good source of potassium, vitamin C, calcium, vitamin E, B vitamins and trace minerals [source: Erman]. Taro gets some solid superfood cred, but make sure to fully cook this starchy root vegetable before eating.

The leaves of the taro plant are no nutritional slumps, either. They taste sort of like spinach but have a hardier texture. They're also good sources of fiber, vitamins A and C, and protein [source: Specialty Produce].

Raw taro contains calcium oxalate, and you do not want any part of this compound. It's like tiny knives that cover the leaves and root of the taro plant. When you eat uncooked taro, the calcium oxalate makes your mouth feel numb. Eat too much, and you'll feel like you're choking [source: Croll]. This toxin also contributes to kidney stones [source: Watson].

Thoroughly cooking taro leaves and roots destroys enough of the calcium oxalate to make them edible. Because this compound can also irritate your skin, you should wear gloves when you're handling the raw plant.

Cassava goes by many names: arrowroot, manioc, tapioca, kassave, mandioca and yuca, but it's different from yucca, an inedible, ornamental plant [source: USDA, Durand]. Whatever you call it, you should only eat it cooked, and only eat the root peeled before it's cooked [source: China Daily].

As with taro, you can eat both the roots and leaves of the cassava plant. This native South American plant is easy to grow in humid climates, and the root is a good source of nutrients, which is why it's now cultivated across South America and parts of Africa. Cassava leaves are also edible when cooked [source: O'Hair].

The toxic culprit in uncooked cassava is a group of compounds that turn into hydrogen cyanide in your body. Hydrogen cyanide interferes with your body's use of oxygen, basically "drowning"—or chemically asphyxiating your organs [source: CDC].

To cook cassava roots properly, you should always peel them first and discard the peel. Then, you can fry them like you would potato chips or french fries. You can also boil the roots just like potatoes, but make sure that they're completely cooked through.

Cassava leaves don't require quite as much care, but you still need to cook them, too. Once they're thoroughly boiled, they're safe to eat and taste similar to collards or other hardy dark, leafy greens [source: Kwok].

You may have grown up eating lima beans, but you surely never ate them raw. That's because lima beans have linamarin, which breaks down into cyanide. And you definitely don't want to ingest cyanide. Where you buy your lima beans will likely affect how much linamarin they contain, too. Those grown in the U.S. tend to have lower levels than those grown outside of the country [source: Baum]. But you should still cook them thoroughly, regardless of where they are grown, as ingesting even a small amount can cause headache, dizziness, nausea, vomiting, rapid breathing and increased heart rate, according to the U.S. Centers for Disease Control.

Luckily, it takes only about 10 to 20 minutes to cook lima beans for them to be safe to eat.

We hate to bust your bubble, but you shouldn't eat raw flour. That means you have to stop eating raw cookie dough, too. Raw flour can make people sick, as was documented during a 2016 E. coli outbreak, which was traced back to raw flour. The CDC says we should avoid any food could contain uncooked flour. That's because raw flour has high amounts of phytates, which can bind to minerals like iron, zinc and calcium and prevent our bodies from absorbing them. Just be sure to cook flour well before you use it in a roux and stay away from the cookie dough.

Unprocessed olives won't make you sick or kill you, but chances are you won't want to eat one. Olives right off of the tree contain a high concentration of a compound called oleuropein, which gives them a bitter taste. Brining olives breaks down the oleuropein, yielding the delicious olives that we all know and love [source: Cook's Info].

What's interesting about raw olives is that while they don't taste so great, there's some evidence that oleuropein has potential health benefits, and olives are the only known food-based source of the compound [source: Phenol-Explorer]. You can actually buy oleuropein supplements, and some research suggests that it's an antioxidant and anti-inflammatory compound that could protect heart and brain health [source: Omar].

There are a few different ways to prepare olives so that they're palatable. Soaking in fresh water will remove some of the bitterness, but brining them for a few weeks or even a few months in salty water or packing them in salt are preferred [source: Bradley]. Different olives require different brining times, so this is sort of a "taste it and see" process. Or just grab a jar from your favorite producer. It's much easier.

There are two main reasons to cook wild mushrooms rather than eating them up raw. Wild mushrooms can be tough to digest, so cooking them helps you avoid gastrointestinal distress. But many wild mushrooms also are toxic and potentially deadly. Cooking breaks down the harmful compounds, leaving you with a bowlful of mushroomy goodness [source: Campbell].

While many raw foods can be hard to digest, wild mushrooms are especially difficult. Mushrooms' cell walls are different from the cell walls of fruits and veggies, and cooking breaks those down, so our bodies can handle processing the tough fungal cells. Breaking down those cell walls with cooking also helps you get more of their nutritional value [source: Campbell].

One caveat: There are a very few wild mushrooms that you can eat raw, so you'd better be an expert in identifying them before you decide to pick a few and cook and eat them. Different wild mushrooms also need to be cooked differently. Some toxins break down when you expose them to heat. Others need to be boiled away [source: Campbell]. Your best bet with wild mushrooms is to do your research to make sure that you cook them safely, and buy wild mushrooms only from trusted, reliable purveyors. It's literally a life-and-death issue.

While the danger associated with eating uncooked or undercooked pork has decreased since the '70s and '80s, you still shouldn't eat your pork raw or rare. Pigs are raised a lot differently than they used to be, but there's still a risk that you'll contract one of two nasty parasites from eating pork: trichinosis or pork tapeworm [source: CDC].

Trichinosis is a parasite that takes up residence in your small intestine after you eat infected meat, and pigs aren't the only animals that can harbor it. Raw bear, cougar, wolf, fox and walrus are also potential carriers [source: CDC].

The first signs of trichinosis are stomach issues like nausea and vomiting. In the week after infection, the parasites reproduce, and their babies enter your bloodstream. When this happens, you can show symptoms from muscle pain to pink eye. Very severe cases can lead to death, though it's rare [source: Mayo Clinic]. Trichinosis cases have gone down drastically as the pork industry has made systemic safety changes and awareness of proper cooking has increased; the CDC now only receives about 20 reports of trichinosis per year [source: CDC].

Pork tapeworm is actually worse than trichinosis. An infected person can range from having no symptoms at all to having seizures. In fact, pork tapeworm is one of the top causes of seizures worldwide [source: Doerr].

The good news is that it's not hard to cook pork safely. Cook ground pork until there is no pink flesh inside at all and the meat reaches an internal temperature of 160 degrees Fahrenheit (71 degrees Celsius), though large cuts of pork may still be slightly pink and cooked to just 145 degrees Fahrenheit (63 degrees Celsius) [source: FoodSafety.gov].

This list might make you feel like you're taking your life into your hands every time you pick up your fork, but with proper cooking, even these foods are safe to eat. Bon appetit!