Nearly every reference to healthy eating will list fresh fruits and vegetables at the top of the must-eat list. That’s no surprise, considering that together, they can provide nearly every vitamin and mineral a body needs. While some produce options can be gobbled up from the outer skin to the inner seed, there are parts of certain fruits and vegetables that contain dangerous substances. While most of these substances are not toxic in small doses, they can definitely make you sick, especially if you have any sort of compromised system, allergies or food sensitivities. Even the healthiest eater should be aware of the dangers that lurk in their food. Here’s a reference to the parts you should avoid in your favorite fruits and veggies.

person spraying green apples with pesticides

Non-organic skins

Before we get into specific types of fruits and vegetables, it’s important to mention the role organic growing practices have on food. That’s because conventional growing methods douse produce with pesticides, herbicides and insecticides. If you consume the edible skin on conventionally raised pears, apricots, grapes and carrots, you are allowing those chemicals directly into your system. It makes the case for buying certified organic products raised sans the toxins. At the very least, be sure to thoroughly wash your produce before eating.

Related: 15 fresh ideas for leftover fruit that will reduce your food waste

one cut open apple on top of other apples

Apples

Full of all kinds of nutrients, an apple a day can indeed help keep the doctor away. But stop short of eating the entire apple, because the seeds contain the amygdalin molecule, which produces cyanide once ingested. In small doses, it will not cause serious illness. But take heed in the warning surrounding the word cyanide, or you may suffer a serious ache in the pit of your stomach.

cherries with pits on a cutting board

Pits

Speaking of pits, toss the center of cherries, apricots, peaches, plums and apricots. They contain the same organic cyanide components as apple seeds. Even though they aren’t likely to send you to the emergency room, it’s best to avoid aggravating your system.

wood bowl of almonds

Raw almonds and cashews

This one might surprise you, because nuts aren’t typically listed under the category of fruits or vegetables. That’s because almonds and cashews are not actually nuts, but rather seeds. While seeds offer lots of yummy benefits, these two varieties also contain cyanide — but only in their raw form. Now don’t be too alarmed, because it is illegal to sell truly raw almonds in the U.S. Even those packaged and clearly labeled as raw have been steamed or cooked another way. They’ve all been through the pasteurization process, too, after a salmonella outbreak a few years ago was trailed back to the fruit.

lemon and limes and their seeds on burlap

Lemon and lime seeds

All parts of lemons and limes can be consumed, and they offer many health benefits. However, if you have a condition that recommends against ingesting seeds, you will want to avoid these citrus seeds. They can be hard to digest.

rhubarb growing from ground

Rhubarb leaves

Hear the word rhubarb and you likely think of the sweet pie served across the country. But see rhubarb on the plant, and you might be surprised to see a fleshy pink to lime green, celery-shaped stalk. The taste of raw rhubarb is extremely tart and favored by few. As unappealing as the stalks might be, the leaves are actually quite poisonous. The leafy green portion contains dangerously high levels of oxalic acid, which can cause serious kidney damage and even death. While it does take high quantities to cause this severity of illness, even a small amount can make you feel sick.

Related: 8 of the best fruits and vegetables you can eat in their entirety

chopped cantaloupe

Cantaloupe skin

While you can power right through the skin of many fruits, the outer rind of cantaloupe should be avoided. That’s because it is extremely susceptible to mold, which can make you quite ill.

lot of lychee

Lychee and ackee

Lychee can be a spectacularly sweet treat. But if eaten while unripe, it can cause fever, convulsions and seizures, especially in individuals who are malnourished or have eaten it on a completely empty stomach. The unripe fruit appears to lower blood sugar, which can cause hypoglycemia. Ackee contains the same poison as lychee and is always cooked before consumption.

starfruit on wood table

Starfruit

Although mostly safe for healthy individuals, starfruit can be fatal if you have any sort of kidney condition. Without proper kidney function, the toxins in starfruit can affect the brain and cause neurological issues. Early signs of a reaction to starfruit include hiccups, confusion and seizures.

tiny red asparagus berries

Asparagus

Asparagus is a healthy vegetable known for its firm, green stalk. The plant also produces enticing red berries that are toxic and can cause vomiting and diarrhea, even in small doses.

yellow potatoes with slightly green skin in a woven basket

Potatoes

Potatoes have the potential to develop a green color just under the surface of the skin when exposed to light. This green color is an indication that it has produced too much solanine, a natural glycoalkaloid, that can cause headaches, nausea, fatigue and intestinal issues. Store your potatoes in a cool, dark place, and avoid consuming green areas that develop.

cassava growing in the ground

Cassava

Cassava is ubiquitous in many parts of the world. Those who consume it regularly are acutely aware that it must first be dried, soaked and cooked properly, as consuming the raw form can result in serious health conditions.

With these exceptions in mind, remember that fruits and vegetables are the best foods you can source for your body. Be informed about potential risks, and then enjoy the bounty provided by nature.

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