Is Unpeeled Fruit More Nutritious?

Is Unpeeled Fruit More Nutritious?

How important is eating the peel of a fruit ?

Fruit is naturally sweet and tasty and it’s a good alternative to dessert when you need a “sweet” fix. Fruit is also an excellent source of vitamins, minerals, fiber, and phytonutrients. Biting into an apple or spooning up a bowl of berries certainly beats nibbling on something processed and sweet like a doughnut or cookie!

One advantage of fruit is that it tastes delicious raw. That’s important since cooking destroys some of the vitamins in fruits and vegetables. A vegetable may start out being nutritious, but after you cook it and place it on the table, some of the vitamins may have gone the way of the water you cooked them in.  Vitamin C is particularly heated sensitive. When you cook vegetables, you can lose up to half of their vitamin C content, depending upon how you cook them. That’s why fruit is the best source of vitamin C.

When you think of vitamin C, citrus fruit probably comes to mind.  Surprisingly, citrus fruit doesn’t top the list of vitamin C sources. Kiwis, guavas, and acerola cherries are an even better source of vitamin C and when you vary the type of fruit you eat, you get a diversity of phytonutrients as well.

Should You Peel Fruit or Eat It Whole?

Should you peel the outer skin of a piece of fruit or eat it with the skin still on? Leave it on! Why should you not peel fruit? For one, the peel is an excellent source of fiber. In fact, the outer skin contains much higher quantities of fiber than the flesh inside the fruit.

Fruit has a number of bioactive ingredients and many of them are concentrated in the peel of the fruit rather than the flesh inside. For example, a study found that the outer skins of passion fruit contain active compounds that improved the symptoms of wheezing in people with asthma. Apples have peels rich in phytochemicals called triterpenoids. These chemicals, in the laboratory, reduce the growth of cancer cells.

Apples contain a diversity of nutrient and phytonutrients. In fact, researchers have isolated a variety of components from apple peels with bioactive properties, including flavonoids, triterpenoids, organic acids, and plant sterols. Some of these components have anti-inflammatory properties and the potential to prevent the formation of blood clots and reduce the spread of malignant cells. Plus, apple peel is rich in pectin, a soluble fiber that helps with blood sugar control.  If you peel an apple, you miss out on some of these perks!

In a study published in the Journal of Functional Foods, researchers isolated a variety of chemicals with high antioxidant activity from tropical fruit peels, more than can be found in the flesh. Even fruits where you don’t typically eat the peel have potential health benefits. For example, orange peels are rich in d-limonene, a chemical with anti-cancer activity in the laboratory. This chemical seems to block certain pathways that fuel cancer growth and survival.

The exterior of watermelon has assets as well. The sweet interior of watermelon may taste better than the rind, but the rind contains significantly more citrulline, a compound your body converts to arginine, an amino acid associated with heart and blood vessels healthy.

What about Pesticides?

One concern about eating the peel of fruit is the potential for pesticide exposure. It’s true that some fruits are heavily sprayed with chemicals. In fact, more fruits make the “dirty dozen” list (the list of produce most heavily tainted with pesticides) than vegetables. Although you will likely find more pesticide residues on the outside of fruit than the inside, the peel is still permeable to chemicals and some can reach the inside of the fruit. Pesticides are more likely to migrate into the flesh of thinner-skinned fruits than thicker ones. For example, honeydew, watermelon, and cantaloupe have thick rinds that form a barrier against pesticides reaching the interior. In contrast, an apple has a very thin skin that offers little protection against pesticides migrating inwards. So, removing the peel may lower pesticide exposure but not completely eliminate it.

One way to get around the pesticide issue is to buy organic fruit whenever you can, especially for fruits that make the dirty dozen list. Even if you peel non-organic fruit, you’re still getting pesticide exposure. It’s also a good idea to choose fruit grown in the United States. Other countries have different safety standards and may allow pesticides that are prohibited in the United States. If you don’t buy organic, wash and soak fruit in a solution of baking soda and water for 15 minutes and then rinse. A study found this was most effective for removing pesticide residues from the surface of the fruit.

Should You Buy Organic?

The best way to get maximum health benefits from eating fruit is to buy organic fruit whenever possible. Then, keep the skin intact to get the benefits of the fiber along with the additional phytochemicals. The extra fiber and phytochemicals you get makes eating the peel is worthwhile in most cases. If you buy organic oranges and lemons, use a zester to make citrus zest from the peel. It tastes delicious in soups, stews, sprinkled on vegetables and in smoothies and yogurt. Citrus peel is also a surprisingly good source of vitamin C, calcium, and bioflavonoids with anti-inflammatory activity. Plus, orange peel contains hesperidin, a flavonoid linked with lowering of blood pressure.

Fruit is a tasty snack that’s easy to carry with you to work. The natural sugar in fruit has only a modest effect on blood sugar since it’s combined with fiber. But, if you’re cutting back on all sugar, even natural sources, berries are a good choice as they’re naturally low in sugar. Vary the types of fruit you eat and choose different colors to get a diversity of nutrients and phytonutrients.

The Bottom Line

Yes, fruit has more potential health benefits if you eat the peel too. But make sure you’re buying organic fruit if you eat the whole fruit. Enjoy the benefits that unpeeled fruit offers!

 

References:

Journal of the Saudi Society of Agricultural Sciences. Volume 17, Issue 4, October 2018, Pages 351-358.
NHS.UK. “Passion fruit peel ‘relief’ for asthmatics”
J Agric Food Chem. 2008 Nov 12;56(21):9905-10. doi: 10.1021/jf8015255. Epub 2008 Oct 2.
Memorial Sloan Kettering Cancer Center. “D-Limonene”
Journal of Functional Foods. Volume 37, October 2017, Pages 501-506.
2012 International Conference on Environment, Chemistry and Biology IPCBEE vol.49 (2012)
The New York Times. “The Advantages of Peeling Fruits”

 

Related Articles By Cathe:

Does Peeling Fruits and Vegetables Eliminate Most of the Pesticides?

Five Reasons to Eat the Peel

Can an Ingredient in Apple Peels Fight Obesity?

 

 

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