My mom used to always say “eat the skin, it’s the best part.” Was she right? Isn’t it called a “peel” for a reason? Turns out mom was right—for the most part.
For many fruits and vegetables, the skin—and the flesh closest to the skin—is higher in nutrients than the flesh. The bright color of the skin is due to its phytochemical composition. These chemicals protect produce from oxidation and pests. Leaving the peel on is usually best if your goal is to maximize the health benefits of produce.
However, the skin contains the majority of pesticides and other contaminants that may be on the food. If you can’t buy organic, or want to minimize your toxin load, then peeling foods that tend to retain high pesticide levels, like apples and pears, may be best for you. Also, some skins are simply unpalatable or indigestible, like avocado and pineapple; these should always be discarded. A food-by-food detailed guide is further below.
Note: small children should usually eat peeled produce, to ensure the food does not present a choking hazard.
For everyone, proper preparation of produce is key to maximizing nutrition and minimizing potential harm.
Minimize your pesticide exposure
Nearly 70 percent of fresh produce sold in the U.S. contains residues of potentially harmful chemical pesticides, according to the EWG’s analysis of the latest test data from the federal Department of Agriculture (conducted in March 2020). This is after washing and peeling! Other studies confirm that pesticides can penetrate the peels of some foods—usually those wth thinner skins, like apples.
I don’t know about you, but I find this information disturbing. I try every day to eat as many fresh fruits and vegetables as I can. Am I just poisoning myself? How can we all eat more produce without doing more harm than good?
The best way to minimize pesticide exposure is to buy organic. I realize that can get expensive. If you can’t buy everything organic, prioritize the foods from the EWG’s “Dirty Dozen” list— the top 12 produce items highest in pesticide residue. They are, updated for 2020:
- Strawberries
- Spinach
- Kale
- Nectarines
- Apples
- Grapes
- Peaches
- Cherries
- Pears
- Tomatoes
- Celery
- Potatoes
Even when you buy organic, thoroughly wash the food under running water to remove any contaminants.
The good news is that there is a list of produce items called the “Clean 15” that the EWG has found to be lower in pesticide contamination. You can feel relatively safe buying these foods non-organic:
- Avocados
- Sweet corn
- Pineapple
- Onions
- Papaya
- Sweet peas (frozen)
- Eggplants
- Asparagus
- Cauliflower
- Cantaloupes
- Broccoli
- Mushrooms
- Cabbage
- Honeydew melon
- Kiwi
Again, absolutely wash or peel these foods before eating them to ensure they are as safe to eat as possible.
The benefits outweigh the harm
Dr. Michael Greger, of the excellent nutrition website NutritionFacts.org, acknowledges the pesticide problem, but recommends that it not prevent us from eating fresh produce. The nutritional benefits outweigh the harm, for most people. Just take care to properly prep your produce and minimize your exposure.
How to clean produce
Whether or not you buy organic, wash the item well under running water, and use a scrub brush on firm produce. Yes, even if you plan to peel it. When you slice into a food, any microorganisms or pesticides on the peel may be carried by the knife into the food.
What about fruit and veggies washes? Dr. Greger of NutritionFacts.org published a review of the literature, and they conclude that store-bought washes are not much more effective than tap water and rubbing or scrubbing. But a 10% salt water solution does remove significantly more pesticide residue than water. Be sure to rinse off the salt before further preparing the item. This step may be worth it for the dirty dozen foods at least.
With foods that can be “peeled” by hand, like onions, iceberg lettuce or bananas, you don’t have to wash them because you are removing the exterior before you slice or bite into them. Wash your hands thoroughly after removing the outer layers.
Another tip: don’t buy pre-cut fruit and veggies. You can’t count on whoever prepared them to have washed the outside of the items and kept the knife clean. Pre-cut produce is certainly convenient. But the minute it hits the store shelves, its freshness starts to decline, and it’s more expensive, too. Prepping your own produce is safer, cheaper and your food will be tastier.
Here’s a play-by-play on whether to eat the peel of specific fruits and vegetables:
Apples
Eat the skin, but wash apples thoroughly, and buy organic if possible. The skin is very high in healthy polyphenols; they provide the rich color of apples’ outsides. Different varieties have different health benefits, but all skins have concentrated nutrients.
However, waxy, thin apple skin tends to hold onto pesticides—apples are on the dirty dozen list. Peel them if your top priority is to minimize pesticide exposure.
According to the USDA Food Central Database (see Resources), a whole apple has 23% more vitamin C than a peeled apple; 32% more magnesium; and 67% more fiber. And all of the folate in an apple is in the peel.
Apricot
Eat the skin (organic, cleaned). One study showed that across 37 varieties of apricots, the beta carotene content correlated with the color of the skin: the darker orange the skin, the higher the content of this nutrient.
Avocados
Always peel avocados. Compost or discard.
Bananas
Believe it or not, you can eat banana peel. Whether you want to or not is up to you. Banana peel doesn’t contain toxins, and it has significant amounts of potassium, fiber, antioxidants, polyunsaturated fats and essential amino acids. Unripe peels have more nutrients, but riper peels are sweeter. Buy organic if you intend to eat the peel. Wash it, cut off the brown top and base, and add the peel to smoothies or banana bread. You can also find recipes online that use banana peels as a vegan substitute for pulled pork. I’ll be honest, I haven’t tried this one, folks; let me know how it goes if you do.
Broccoli
There isn’t really a skin on broccoli, but many recipes advise peeling off the tougher, outer layer of the stems before cooking or eating them raw. Doing so will make them more tender. I can’t find any studies proving this, but if you do so, you are likely removing many of the nutrients. The outside layer of the stem is darker green than the inner layer, and color is typically an indicator of nutrient content. Don’t peel, unless that’s the only way you’ll eat it. After all, peeled broccoli is better than no broccoli. Clean well and buy organic if possible.
Carrots
As with broccoli, recipes typically advise that the outer layer of carrots be peeled off before cooking or eating them raw. At least one study showed that the polyphenol and carotenoid content of cooked carrots is higher when they are unpeeled. Vitamin C, niacin and phytonutrients are most concentrated in the peel.
Using data from the USDA food database, I calculated that unpeeled carrot has 15% more fiber, 54% more calcium and 18% more vitamin C than peeled.
However, you may have noticed that the skin and flesh of carrots are the same color. That’s the beta carotene in carrots, and it is relatively evenly distributed throughout the vegetable. So you don’t lose a disproportionate amount of this nutrient when you peel a carrot.
If the carrot is very dirty or bruised, a light peel will help ensure that your food is clean and safe to eat. As with other produce, if peeling makes you more likely to eat it, peel away.
Celery
Unlike most of the recommendations in this article, I do suggest “peeling” celery, Like broccoli and carrots, celery doesn’t have a skin, technically, but it does have those stringy outer pieces that can get stuck in your teeth and make eating celery a less enoyable experience.
There are no studies I’m aware of that say these strings contain significantly more nutrients than the inner stalk. And the color of celery is relatively uniform, suggesting the nutrient content may be evenly distributed. Perhaps the strings contain more fiber. But if getting rid of those strings makes you eat more celery, then do so. More importantly, celery is on the dirty dozen list; it tends to retain higher levels of pesticides. So peel away.
Citrus—Oranges, Lemons, Limes, Tangerine, Clementine, Grapefruit
You will need to peel citrus before eating, but there is still a great deal of value in the peel. One study found that the peel of oranges and other citrus fruit had more antioxidants and mineral content like iron, copper and magnesium than the fruit itself. Plus zest added to other foods tastes and smells divine.
If you are going to use the peel, buy organic; it may not be possible to wash off all pesticide residue from bumpy citrus peel. If you have organic citrus, zest before peeling.
To zest citrus, use a grater or Microplane over a piece of wax or parchment paper. If you’re not going to use the zest right away, it can be saved in the refrigerator in a bag or container for a day or two. It also freezes well, for up to three months. Add zest to smoothies, pasta, salad dressing, pancake or waffle batter, oatmeal, herb butter, granola and baked goods.
Or, forget zesting and just save the peel in the refrigerator. You can drop clean peels into drinks like hot or ice tea, juice, water, or cocktails for extra flavor and nutrition. Cut peels into a spiral for added flair. You can also candy citrus peels; here is an easy recipe from Allrecipes.
What about the pith? That white stringy substance between the peel and the flesh of an orange tastes bitter or tasteless for most people. But eating it won’t hurt you, and it amps up your fiber intake from the fruit. Pith also contains numerous flavonoids, including hesperidin, which may help blood vessels function better, and may reduce inflammation. Eat if you like.
Cucumbers
There is no need to peel cucumbers. The outer skin is deeper in color than the inner flesh, an indicator of its richer nutrient content. As always, wash thoroughly and choose organic if you can. According to calculations based on USDA data, leaving the skin on will provide you 39% more beta carotene, 37% more vitamin A, and 78% more vitamin K.
if you find the skin unpalatable, consider partially peeling it. Peel strips all the way around the vegetable, leaving some places unpeeled. This can be attractive when the cucumber is then sliced into disks, but know that you are losing some nutrient content when you remove some of the skin.
Eggplants
Traditional eggplant recipes recommend peeling eggplant, and salting and draining it, to remove bitter compounds. These steps are no longer necessary with modern cultivars, which have been bred to be more palatable. Choose smaller eggplant, which tend to be younger, less bitter, and have more tender skin (buy organic if possible and wash well). Definitely leave the skin on in these cases for maximum nutrition— plus, the color is pretty in any dish. Larger eggplants are often older and may have tougher skins that are less pleasant to eat. Once again, if peeling the eggplant makes it more “appeeling” to you, then peel away.
As you might guess from the deep color of eggplant skin, it contains many of the nutrients in the vegetable (fruit, actually). The skin of dark purple eggplant contains nasunin, a powerful antioxidant that helps battle fee radicals.
Kiwi
You can eat the skin of kiwifruit. If it’s a fuzzy-skin variety, you can scrape off the hairs if you prefer. As always, wash it first. The Zespri Kiwi company says kiwifruit contains significant amounts of these nutrients in their skin:
- Soluble and insoluble fiber
- Folate
- Vitamin E
- Polyphenols
Kumquats
Eat the peel of kumquats. Unlike other citrus fruit, the sweetness of kumquats is in the peel, while the flesh is tart. In fact, you should prefer the peel to the pulp. Some people nibble the top off of kumquats, squeeze out the juice, and then eat, for a sweeter-tasting experience. There are higher amounts of health-giving polyphenols and flavonoids in the kumquat’s peel than in the pulp. Buy organic if you can, and wash well.
Mangos
Although mango skin is high in fiber and nutrients, it is best to peel it before eating the fruit. The peel contains a substance, urushiol, which, interestingly, is the key ingredient in Japanese lacquer, as well as the irritating chemical in poison ivy, oak and sumac. The amount in mango skin won’t hurt you unless you are allergic to urushiol. But the peel is bitter and the benefits aren’t worth it, in my view.
The thin peel on juicy mango flesh can be tricky to remove, but there are tools you can buy, like this one on amazon, which pits, slices and peels mangoes in two easy steps.
Melon—Cantaloupe, Crenshaw, Honeydew, Watermelon
Cantaloupe rind is not edible. Its rough-textured outer skin can trap microorganisms, so wash it carefully before cutting it up.
Crenshaw rind is also inedible. Wash first.
Smoother-skinned honeydew is also inedible. Again, wash it before cutting, to ensure the fruit doesn’t become contaminated during preparation.
Don’t eat watermelon rind raw. But you can pickle it and eat it. There are many recipes for pickled watermelon on the internet; here’s one.
Eating the rind means zero-waste, and the rind provides a different set of nutrients than the flesh. Watermelon contains significant amounts of the amino acid citrulline, which is concentrated in the rind. Citrulline opens up blood vessels, which in turn can improve libido, lower blood pressure and improve exercise performance.
Nectarines
You can eat nectarine skin along with the flesh. Once again, studies show that antioxidant concentrations are higher in the skin. A study on peaches, which are closely related to nectarines, shows that anthocyanins in particular accumulate in the red coloration of the skins. Anthocyanins are beneficial plant pigments that give fruit and vegetables their deep red, purple or blue hues.
Having said all that, nectarines are on the dirty dozen list. For that reason, buy organic or wash very well, and consider peeling if minimizing toxin load is a priority for you.
An easy way to peel the thin skin of nectarines is to drop them in boiling water for 30-60 seconds; then place them in an ice bath. Once cool, the skin should slip off; you won’t even need a knife.
Papaya
Papaya skin is not edible. Wash well before peeling, then compost or discard the peel.
Peaches
Peach skin can be eaten. The information in the section on nectarines, close cousins of peaches, applies here. Antioxidants are concentrated in peach skin. So, unfortunately, are pesticides. Peaches are on the dirty dozen list, so buy organic or peel to minimize pesticide exposure.
The same peeling method for nectarines works on peaches: drop them in boiling water for 30-60 seconds; then place them in an ice bath. The skin will come away easily in your hands.
Pears
Pear skin should be eaten, ideally. The most colorful part of the pear is the skin, and as you now know, that’s where many of the nutrients lie. Studies confirm that the greatest concentration of polyphenols (beneficial antioxidant compounds) is highest in the peel—six-to-twenty times higher, in fact.
However, pears are on the dirty dozen list. They tend to retain a high degree of pesticides, even after peeling. Either buy organic, wash very thoroughly, or peel, if your top priority is to minimize pesticide exposure.
Pineapple
Pineapple skin is not edible. Compost or discard.
Potatoes (White or Sweet, Yams)
All potato and yam skins are edible and contain a high concentration of the vegetable’s nutrients and fiber. However, potatoes are on the dirty dozen list. I recommend only eating organic potatoes and yams, and washing them well before cooking and eating them. If your potatoes or yams aren’t organic, I’d avoid eating the peel. And never eat skin that has green spots or sprouts (these areas contain toxins).
Plums
Eat plum skin along with the flesh. Plum skin contains a polyphenol called chlorogenic acid that may have anti-diabetic, anti-carcinogenic, anti-inflammatory and anti-obesity effects. Buy organic if you can, and wash well.
Squash—Including Acorn, Butternut, Honeynut, Kabocha, Pumpkin, Red Kuri, Spaghetti, Sweet Dumpling and Zucchini
Squash skins are edible, but not all are palatable:
Pumpkin rinds are not edible. Discard (or make a jack-o-lantern)!
Eat the skins of honeynut, delicata, red kuri and sweet dumpling squash. They are all thin-skinned varieties and when cooked, their skins becomes soft and edible.
Acorn squash, especially when roasted sufficiently, is also fine to eat with the skin.
Butternut and kabocha may also be palatable when cooked. Some will be too tough and stringy. Choose younger, smaller squash for the most tender skin.
Spaghetti squash is an exception—its skin is unpleasant to eat: discard this one.
Zucchini skin, is edible and packed with nutrients. The mineral content in zucchini is higher in the skin than in the flesh.
As always, choose organic if you can, and wash well.
Quick takeways
- Most produce has edible skin and should be eaten to give you the maximum nutritional benefit from the food
- Nutrients in produce are usually concentrated in the skin or flesh closest to the skin
- Foods that should be peeled include: avocado, bananas, cantaloupe, celery, clementine, grapefruit, melon, oranges, lemons, limes, mango, papaya, pineapple, pumpkin, spaghetti squash, tangerine and watermelon
- Buy organic whenever possible, but especially when it comes to the dirty dozen; otherwise, you may want to peel those foods (that have peels) as well
- Wash thoroughly, even if you intend to peel the item
- Consider using a 10% salt water rinse to thoroughly clean produce, especially those items on the dirty dozen list
Happy eating!
Phytonutrients can help your energy levels by contributing to your overall health and wellness in many ways. Read about the different benefits of each color family: yellow/orange, red and blue/purple.
Guess which apple variety is healthiest? Find out here.
Click here to get my pics for the healthiest breakfast cereal brands.
Resources
- https://www.ewg.org/foodnews/summary.php.
- https://nutritionfacts.org/topics/pesticides/.
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- https://www.allrecipes.com/recipe/18999/candied-citrus-peel/.
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