To peel or not to peel. That is the question. Actually, it is one of the first questions you run into as a beginner juicer.
The answer is a little more nuanced than a simple, “PEEL” or “DON’T peel.” Some fruits and vegetables should be peeled and some are better with the skins left on. Here are a few guidelines to follow when deciding whether to peel or not.
Organic vs Non-organic
This is one of the foremost considerations when deciding whether to peel or not. Even for fruits and vegetables that are generally better with the peels left on (see below), you should peel it if it’s non-organic.
Some fruits and vegetable peels – such as apples and cucumbers – contain ample nutritional benefits and are best left on. These also happen to be on the EWG’s Dirty Dozen list of produce commonly contaminated with toxic insecticides. If you can’t buy all organic, try to at least get the produce that’s on the list.
Fruits and Vegetables You Should Juice with Peels ON
Some fruits and vegetables have peels that are full of nutritional benefits. Here are a few peels you should be consuming:
Apples: Apple peels contain much of the nutritional benefits of this fruit. According to Cornell University’s Chronicle Online, apple peels are especially rich in powerful phytochemicals like flavonoids and phenolic acids since it is at the peel where the fruit interacts directly with the sunlight.
Another study from the University of Illinois says about two-thirds of an apple’s fiber content exists in its peel. Apple peels also contain important minerals such as calcium, potassium, phosphorus, folate and iron as well as antioxidants (vitamins A and C). Another fairly recent study singles out apple skin for its potential to prevent loss of muscle tissues.
The point is: apple skins are highly nutritious and this is one fruit you should plan to buy organic so you can get the full benefits!
Bananas: Although you can’t juice bananas, you can juice their peels. If that sounds a little gross, don’t worry – it’s actually quite yummy. You can also add these nutritious peels to your smoothies. And the benefits are unexpectedly great. Banana peels are rich in serotonin, which is associated with mood; people with depression are known to have lower serotonin levels. Researchers from Chung Shan Medical University in Taiwan have found that banana peel extract can ease depression as well as benefit the eyes, since the peel is also rich in the antioxidant lutein, which protects eye cells from exposure to ultraviolet light.
Beets: Beet peels are a matter of (taste) preference. I generally never peel these, especially since I only get them organic. But other people might not like the slight taste of “dirt” that tends to come with unpeeled beets. If that really bother you, you can give them a rigorous scrub or just peel them all together.
Cucumbers: Cucumber peels are full of nutritious benefits. The skins are rich in fiber and contain a variety of beneficial minerals such as silica, potassium and magnesium – making it ideal of hydration as well as for maintaining healthy tissue. Silica is an essential component of healthy connective tissue in muscles, tendons, ligaments, cartilage, and bone. Cucumber juice – with the (organic) peels left on – is an excellent source of silica to improve skin health.
Eggplant: Some people are reluctant to juice eggplant because of rumors of its toxicity (which isn’t actually true – click here for details), but if you are going to juice eggplant, make sure to leave the skins on. They are chock full of nasunin – an antioxidant that may prevent brain-cell damage – as well as an ample amount of potassium and magnesium. Make sure you juice the eggplant as soon as you buy it – the peels get more bitter with time.
Grapes: Red and purple grapes contain resveratrol – the anti aging miracle that’s been making headlines all over the news and the main reason why red wine is touted as a nutritious drink.
Resveratrol is an antioxidant that helps to protect your body against free radical damage that leads to the aging and disease. The studies that back up resveratrol as an anti aging marvel are based on studies in which mice that were fed resveratrol supplements had better motor coordination and lived longer than mice that didn’t receive any resveratrol. According to these studies, resveratrol works by boosting enzyme activity in the mitochondria of muscle tissue.
This is one of the biggest reasons to eat (organic) red grapes with the skins on – the concentration of reseveratrol is much higher in the skin of red grapes than it is in red wine.
Kiwi: Most people scrape all their kiwi skins off, missing all the nutritional benefits of this furry brown wrapping. But this skin is high in antioxidants and thought to have anti-cancer, anti-inflammatory, and anti-allergenic properties.
Did you know that the kiwi skin contains 3 times the antioxidants of the pulp? At the same time, there’s no denying that it’s rather…tart…so if you can’t stand the taste, try gold kiwi fruit which are significantly less tart-y. You can just juice the whole thing!
Lemons & Limes & Tangerines: Citrus peels are high in powerful antioxidants called super-flavonoids which can contribute to reducing “bad” cholesterol levels. According to a U.S. study, the antioxidants from these peels were 20 times more powerful than those from the juice.
At the same time, the oils from these citrus peels can be tough on your stomach, so make sure you go easy on them. We recommend juicing only half a peel a day
Melons: Melons are great to juice whole – just leave everything the way it is, cut it up and juice. The rinds are where most of the nutrition is, plus the rinds help to dilute the sugariness of the melon. Elaine Bruce of the UK Living Foods Centre says watermelon rinds are the area of the melon where the minerals and enzymes are concentrated. The rinds also contain citrulline, which has antioxidant effects and converts into the amino acid arginine to help remove ammonia from the body. It doesn’t taste at all bad, either!
Fruits and Vegetables You Should Juice with Peels OFF
(Bigger) Citrus Fruits: The peels of oranges and grapefruits contain some oils that can cause pretty bad indigestion. Always peel the peels off oranges and grapefruit before juicing!
Mangoes: Mango skins are edible and I personally prefer to leave them on when I juice. However, they can cause an allergic reaction in some people. The skin of mangoes is filled with vitamins and nutrients, but it also contains a chemical called urushiol – which is found in poison ivy and responsible for the itchy rashes. Not everyone will have an allergic reaction – I don’t – but if you’re not sure, it’s best to avoid eating the skins.
Squash(es): Squashes – like pumpkin, butternut, etc. – have peels that are much, much too hard for your juicer. Make sure to peel these off, but peel as little as possible (so you leave the part that is closest to the peel that is the darkest color of the flesh since this is where the most nutrients are).