Leaves, Seeds and Peels That Are Not Okay to Eat

Reducing food waste is one of the best ways to save time, money and our precious natural resources. I love using up every pip, peel and pit that I can, to get the most out of the food that I bring home. Leftovers get upcycled and bones get made into broth. Stems, leaves and peels are often pureed, sautéed or otherwise transformed so that they all make it onto the menu.

But there are a few exceptions to the rule — there are some plant parts that do not make good eating. This post offers up a list of some of the most common produce items that are best left off of your dinner plate (and composted), and some where the verdict is still out.

Apple and Pear Seeds

An apple a day keeps the doctor away, but don’t knock back too many of the seeds as they contain trace levels of cyanide. Lucky for fruit lovers, the amount of the chemical in one apple or pear seed is negligible and the seed’s hard shell keeps the toxin contained. You would have to crush or pulverize the seeds to release the poison or eat a bowl of cores to encounter any ill effects. But if you see a fair amount of apple eating in your future — perhaps on the way back from a good picking — or if you have little ones who eat the fruit on a regular basis, best to spit the pips.

Apricot Pits

Apricot pits, like those of all stone fruits (such as peaches, plums and cherries) contain kernels, also called noyaux, that are valued for their almond-like flavor. Of the stone fruits, apricot kernels are the most widely distributed commercially and are available in both bitter and sweet varieties. The bitter kernels, often labeled bitter almond, bear a markedly higher level of cyanide than the sweet variety, but the chemical’s presence in both is a concern for many eaters and merits caution from some medical authorities.

The level of poison in a single pit is low so that accidental ingestion of one doesn’t merit a trip to the emergency room. However, some traditional recipes, such as Italian biscotti, rely on the pits’ distinctive almond-like flavor and call for a volume of pits (30 to 40 is not uncommon in baking recipes) that seems to fly in the face of common sense.

The safety of this practice is open to debate. There are those that say treated kernels pose no risk or that cooking reduces the level of toxin in the kernels. The opposing view encourages moderation when consuming the kernels. For me that means one or two kernels in the jam pot but no more, particularly if I’m feeding little ones who have a lower threshold for contaminants.

Elderberry

Elderflower cordial (such as the popular St. Germain liqueur) has become a new addition to the top shelf of many cocktail bars and has long been a favorite of DIY tipple making. It is concocted from the fragrant, white star-shaped flowers of the elder plant, an early summer blooming bush that grows prolifically in temperate regions.

The blooms are followed by red or black berries, depending on the variety of the plant, which are often boiled down and sweetened to make a homemade cold and flu remedy. Raw berries, however, as well as the leaves, stems and branches of the elder plant are toxic. They contain cyanide-inducing glycosides, which can cause nausea, vomiting and weakness. Never juice the raw berries and, when harvesting the flowers, be absolutely sure to leave all other parts of the plant behind.

Mango Skins

Mangoes are from the same plant family as poison ivy and contain very small amounts of the same compound, urushiol, which causes an itchy rash for the majority of us who are allergic to it. For all but those with the highest sensitivity, that does not mean a mango-free diet. But for many, it means that extensive contact with mango skins should be avoided. If you are going to prepare more than one or two mangoes, be sure to wear gloves and wash the fruits thoroughly to remove any lingering sap, which contains a higher level of urushiol than the skin. And, unless you are sure that you have no sensitivity to mango skin, avoid eating it because it can cause swollen lips, inflammation and, in the most sever cases, anaphylaxis.

(Green) Potato Peels

Potatoes that have been exposed to sunlight take on a green cast. The green color is caused by chlorophyll, the compound that makes grass and leaves green as well. Chlorophyll is harmless in and of itself but it is a red flag when seen in potatoes because it indicates the presence of another compound that develops when the tubers are exposed to sun — solanine. Solanine is indeed highly toxic and can cause nausea and worse when ingested in even small amounts. To avoid exposure, cut away any green tinged parts of the potato before proceeding with your recipe.

Potato Leaves

Potato plants have attractive leaves and flowers so pretty that Marie Antoinette wore them in her hair. Although decorative, the leaves and stems of potatoes are not at all edible. They, like green potato peels, contain solanine and the additional toxins arsenic and chaconine. Never eat the leaves or stems of potatoes or feed them to animals.

Rhubarb Leaves

Rhubarb leaves are so lush and plentiful and have such a strong resemblance to Swiss chard that it seems counterintuitive to discard them. But pitch the leaves you must. Rhubarb leaves and the stalks of frost-damaged plants contain oxalate, a highly toxic compound that is poisonous to humans and animals. Trim the stalks completely of any leaf material and discard them in a way that ensures that they will not be accidentally ingested by animals.

Tomato Leaves

Tomato leaf is one of my absolute favorite fragrances. Fresh as a garden and full of the promise of luscious fruit — it almost writes its own perfume ad. But there are as many of us who love the smell as those who abhor it, and an equal amount on each side of the fence when considering the place of tomato leaves in the kitchen. They are part of the nightshade family whose leaves are toxic, surely a strike against them. Yet, food science expert Harold McGee holds that there is little hard evidence proving their toxicity. Chefs like Paul Bertolli, formerly of Chez Panisse, have begun to use them in dishes where their ripe, vine-y flavor informs recipes with a more tomato-y tomato flavor. The verdict? I’d use them as a flavoring but not in any substantial amounts.