Choosing what to eat can often be confusing. There are so many different diets that say conflicting things and knowing which one is best for you can be complicated. What may be good for one person, can be harmful to another. One such way of eating is the raw food diet, which has contradictory information on whether these raw foods are healthier than cooked foods. Some people believe they are and their diets are only comprised of raw foods.
Known as raw foodists, they maintain that consuming only uncooked fruits and vegetables can promote weight loss and help prevent and combat certain diseases. There are three main types of raw foodists – raw vegan, raw vegetarian, and raw omnivorous and they all believe that cooking food destroys key enzymes that make food more digestible.
It may be common knowledge that various cooking methods can leach vitamins and minerals out of some vegetables, but on the other hand, the nutrients in certain other foods — including legumes and grains — become more available to the body when they’re cooked. But then you have to be careful how long you keep them in the fridge, as some foods spoil much faster than you think.
The nutritional value of asparagus and even of tomatoes, for instance, is increased by cooking. Certain other vegetables may be healthier, and taste perfectly fine, when eaten raw, but may cause gas or bloating. Cruciferous vegetables — Brussels sprouts, broccoli, and cauliflower, for instance — are particularly likely to have this effect. This is why dieticians sometimes recommend against eating some vegetables raw.
There are, however, certain foods that should rarely, if ever, be eaten raw because they contain toxins of various kinds. These foods may be eaten raw on occasion, or only in small quantities. The amount of potentially harmful compounds in many of these is so small that you’d have to consume huge quantities of them to experience any ill effects. In other cases, though, even a few bites can cause problems. Kidney beans, for instance, are seriously toxic when eaten raw — even though when they’re cooked, they’re one of the best foods for your gut health.
Here are vegetables you should never eat raw.
1. Cassava
Also known as manioc and yuca, this versatile tuber is a staple throughout much of its native South America and in parts of Africa and Asia and is also the source of tapioca. There are two main varieties, sweet and bitter, but both contain a cyanogenic glucoside called linamarin, which decomposes into poisonous hydrogen cyanide. In sweet cassava, the poison is concentrated near the surface, and peeling and cooking remove all traces of it. It’s laced throughout bitter cassava, however, and that tuber must be grated, thoroughly washed, and pressed before cooking to remove it. Needless to say, neither kind can be eaten raw.
2. Eggplant
Eggplant is a member of the nightshade family (one of its relatives is the so-called deadly nightshade, also known as belladonna), and like other family members contains solanine, a bitter-tasting steroidal compound. Too much solanine can cause nausea, dizziness, and other health problems, and extremely high doses can be fatal. Cooking eggplant lessens its solanine content, however, and most authorities agree that you’d have to eat unreasonable amounts of the vegetable to experience ill effects. Nonetheless, some people are allergic to even small quantities of the compound, so it’s safer not to sample eggplant raw.
3. Green beans
There are more than 130 varieties of green beans, and they are generally considered a very healthful vegetable, full of vitamins A, C, and K. Eating a few of them raw in a salad shouldn’t be a problem, but they’re mildly toxic unless cooked. They also contain lectins — so-called antinutrients that limit the body’s ability to absorb vitamins and minerals and may cause digestive issues. Cooking reduces these to negligible amounts.
4. Kidney beans
There’s an illness called red kidney bean poisoning, characterized by extreme nausea, diarrhea, and abdominal pain. This is caused by a toxin called phytohaemagglutinin, present in high concentrations in raw kidney beans. Heating them insufficiently, as in malfunctioning slow cookers, can increase their toxicity — but thorough cooking renders them harmless.
5. Lima beans
Raw lima beans are like cassava in that they contain linamarin, which decomposes into cyanide. Limas sold commercially in the United States are required by law to have lower levels of the compound than those grown elsewhere, though, and thorough cooking neutralizes the poison. (The beans should be cooked uncovered to allow the linamarin to escape as vapor.)
6. Potatoes
Potatoes contain solanine, like eggplant, and other members of the nightshade family. Consuming too much of this compound can cause a variety of gastrointestinal and neurological problems, including nausea, diarrhea, arrhythmia, dizziness, hallucinations, paralysis, and hypothermia. Potatoes that are turning green have particularly high levels.
Some methods of cooking — primarily deep-frying and boiling — noticeably lower solanine levels, and in any case it has been estimated that a 100-pound person would have to eat a pound of fully green potatoes to experience any ill effects. On the other hand, the high starch content of potatoes makes them hard to digest even when cooked — yet another reason to avoid them raw.
7. Rhubarb leaves
Rhubarb stalks, which look like overgrown red celery, make a delicious pie (often combined with strawberries) and other desserts, but it’s very important to trim every bit of leaf from the stalks before you use them. (It’s a good idea to wash the stalks thoroughly, too.) While rhubarb itself is perfectly safe, and can even be used medicinally, its leaves have a high concentration of oxalic acid, which can cause a host of unpleasant symptoms, including burning throat, nausea, and diarrhea.
8. Spinach
Many of us have eaten raw spinach salads with no ill effects. But spinach, like rhubarb leaves, contains oxalic acid, which limits calcium absorption and may facilitate the formation of kidney stones. Cooking the spinach and discarding the cooking water gets rid of most of the acid. Another issue with the raw leaves is that spinach is particularly susceptible to contamination with E. coli and other bacteria — again largely destroyed by cooking.
9. Wild mushrooms
Cultivated mushrooms are fine to eat raw, and make good additions to salads. Restaurants, especially in Europe, sometimes serve certain varieties of wild mushrooms raw, as well, but in general, the practice is unwise. They’re hard to digest, for one thing. Also, many varieties are mildly — or seriously — toxic when raw and become safe to eat only when cooked. Unless you’re an experienced mushroom hunter, it’s best to avoid them raw.