Leaving the skin on a kiwifruit can increase its fiber content by about 50% while providing additional antioxidants, vitamin E, folate and vitamin C, although people prone to kidney stones may need to limit the peel because of its oxalate content.
By yourNEWS Media Newsroom.
The fuzzy brown peel most people remove from a kiwifruit is not only edible but can substantially increase the fruit’s nutritional value, according to guidance from Cleveland Clinic.
In a Health Essentials report published Feb. 17, 2023, the nonprofit academic medical center said every part of the kiwifruit can be eaten, including the exterior skin. Consuming the fruit whole increases its fiber content by roughly 50% compared with eating only the flesh.
Registered dietitian Gillian Culbertson, RD, LD, said the nutritional advantages extend well beyond fiber, with kiwi skin containing substantially higher concentrations of some beneficial plant compounds than the interior of the fruit.
The peel contains three times as many antioxidants as the flesh, Culbertson said.
The guidance reflects broader nutritional interest in parts of fruits and vegetables that are routinely discarded. Peels and rinds can contain concentrated amounts of fiber, vitamins and plant compounds, meaning removing them can also remove part of a food’s nutritional value.
Kiwifruit presents a particularly accessible example because its entire exterior is edible.
Approximately 60 species of kiwi exist, according to Culbertson, and all have edible skins, although the texture varies considerably.
The familiar green kiwifruit, Actinidia deliciosa, has bright green flesh surrounded by a fuzzy brown skin. Although completely edible, the coarse texture may make the peel unappealing to some people.
Gold, or yellow, kiwifruit offers a smoother alternative. Its bronze-colored exterior lacks the prominent fuzz associated with green varieties, making it easier for some people to eat without peeling.
Growing location and variety can produce modest differences in flavor and nutrient composition, but Cleveland Clinic said the skins of all kiwi varieties can be consumed.
The nutritional difference becomes particularly noticeable when comparing whole fruit with peeled fruit.
A green kiwi eaten with its skin contains approximately 3.5 grams of fiber, while a whole gold kiwi provides about 3 grams, according to the report.
Gold kiwi also gains additional vitamin E when the skin remains intact. Cleveland Clinic said eating the peel increases the fruit’s vitamin E content by approximately 32%.
Folate intake rises as well. Keeping the skin on a gold kiwi increases folate consumption by about 34%.
Folate, also called vitamin B9, plays an important role in the nervous system and in maintaining healthy skin, hair, eyes and liver function, Culbertson said. Adequate folate is especially important during pregnancy because deficiency can contribute to anemia and birth defects.
Vitamin C is another nutrient found throughout the fruit, including the skin.
Culbertson said consuming the peel increases vitamin C intake. One study cited in the report found approximately 161 milligrams of vitamin C in gold kiwi, compared with roughly 85 to 150 milligrams in green varieties.
Other research has examined whether regular kiwi consumption may have visible effects on the skin itself. Scientists at the University of Otago in New Zealand found that eating two kiwis daily for eight weeks improved measures of skin health, including collagen production and skin density.
The peel also contains a substantial share of the fruit’s polyphenols.
Approximately 30% of a kiwi’s polyphenols are located in the skin, according to the Cleveland Clinic report. Polyphenols are antioxidant compounds associated with helping the body counter oxidative stress and inflammation.
The advantages of eating kiwi skin, however, do not apply equally to everyone.
The peel contains relatively high levels of oxalates, naturally occurring compounds found in many plant foods. For people predisposed to kidney stones, consuming large quantities of oxalate-rich foods can increase the likelihood of crystal formation.
“They can mix with the calcium in your body, which stops it from being absorbed properly and can cause oxalate crystals to form in your kidneys and joints,” Culbertson said. “This can lead to kidney stones or gout.”
Cleveland Clinic noted that the American Urological Association advises people susceptible to kidney stones to be cautious with oxalate-rich foods.
That distinction applies particularly to the peel because kiwi flesh contains lower oxalate concentrations.
For people without those concerns, overcoming the texture of a green kiwi may be the biggest obstacle to eating the fruit whole.
Cleveland Clinic recommends thoroughly washing the kiwi and then rubbing the surface gently with a kitchen towel or nylon-bristled vegetable brush. Doing so can remove some of the exterior fuzz without stripping away the skin itself.
Another option is to slice or dice the unpeeled fruit and mix it into a fruit salad. Smaller pieces make the peel’s texture less noticeable when combined with other foods.
Blending a whole kiwi into a smoothie can produce a similar effect because the blender breaks the skin into small pieces while retaining its nutrients.
Gold kiwi may require even less preparation because its smoother skin lacks the coarse hairs found on many green varieties.
The overall nutritional benefit comes from consuming more of what the fruit naturally contains rather than adding a supplement or changing the food itself.
Eating a kiwi with its skin can raise fiber intake by about half and provide additional antioxidants, vitamin E, folate, vitamin C and polyphenols.
For most people, the peel can therefore be treated as part of the fruit rather than waste. Those with a history of kidney stones or other concerns involving oxalates, however, may need to approach the skin differently and consider their individual medical history before making it a regular part of their diet.
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Source: Natural News
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