A kiwifruit (or kiwi), also known as the Chinese gooseberry, is a nutritious, sweet-tart fruit.
They are about the size of a chicken egg, with brown fuzzy skin, vibrant green or yellow flesh, small black seeds and a tender white core.
While many people love kiwis, there is some controversy over whether or not the skin should be eaten. Technically, the skin is edible, but some people dislike its fuzzy texture.
This article reviews the pros and cons of eating the skin so you can decide if you might want to give it a try.
Kiwi skin is very nutritious
Kiwi skins contain a high concentration of nutrients, especially fiber, folate and vitamin E.
- Fiber: This critical nutrient feeds the good bacteria living in your gut. High-fiber diets are linked to lower risk of heart disease, cancer and diabetes.
- Folate: Folate is an especially important nutrient for cell growth and division, and can help prevent neural tube defects during pregnancy.
- Vitamin E: This fat-soluble vitamin has strong antioxidant properties. It helps keep your cells healthy by preventing damage from free radicals.
Eating the skin of a kiwi can increase its fiber content by 50%, boost folate by 32% and raise vitamin E concentration by 34%, compared to eating the flesh alone.
Since many people do not consume enough of these nutrients in their diets, eating kiwis with the skin on is one easy way to boost your intake.
Summary: Kiwi skin is a good source of fiber, vitamin E and folate. Eating the skin increases the amount of these nutrients you get by 30% to 50%.
Most of the antioxidants are in the skin
The skin of the kiwi contains many antioxidants. In fact, there is a higher concentration of antioxidants in the skin than in the flesh of the fruit.
The skin is a particularly good source of two major antioxidants: vitamin C and vitamin E.
Vitamin C is water-soluble, so it’s able to fight oxidative damage inside your cells and within your bloodstream.
In contrast, vitamin E is fat-soluble, and primarily fights free radicals within cell membranes.
Since kiwi skins are rich in both water-soluble and fat-soluble antioxidants, they offer strong antioxidant protection for your entire body.
Summary: Kiwi skin has a high concentration of antioxidants, particularly vitamin C and vitamin E. These antioxidants fight free-radical damage in many areas of the body.
Eating kiwi skin can be unpleasant for some people
Kiwi skin is packed full of nutrients, but eating it can be unpleasant for some people.
People often discard the skin because of its fuzzy texture and strange mouthfeel.
However, the fuzz can be partially removed by rubbing the fruit with a clean towel, scrubbing it with a vegetable brush or scraping it lightly with a spoon.
If you prefer to remove the skin, simply slice it off with a paring knife or cut off one end of the kiwi and use a spoon to scoop out the flesh.
Kiwis can also irritate the insides of some people’s mouths.
This is due to the presence of naturally occurring calcium oxalate crystals, called raphides, that can scratch the tender skin inside your mouth. These microscopic scratches, combined with the acid in the fruit, can cause an unpleasant stinging sensation.
Peeling the fruit can help reduce this effect, since there is a high concentration of oxalates in the skin. However, raphides are also present in the flesh.
Ripe kiwis tend to produce less mouth irritation than underripe fruits, since the soft flesh traps some of the raphides and decreases their effects.
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Summary: The texture of kiwi skin may be unpleasant to some people, and can cause mouth irritation due to the presence of oxalate crystals.
Certain people should avoid kiwis
While kiwis are enjoyable for most people, those with allergies or a tendency to develop kidney stones may need to avoid them.
There have been many documented cases of kiwi allergy, with symptoms ranging from a slightly itchy mouth to full-blown anaphylaxis. Anyone with a severe allergy should avoid these fruits.
Those who suffer from mild symptoms may have oral allergy syndrome or latex food allergy syndrome.
Oral allergies and latex food allergies occur when the immune system reacts to certain proteins, like those found in kiwi, that are similar in shape to birch pollen or latex.
This causes unpleasant symptoms such as itching or tingling in the mouth, numb or swollen lips, scratchy throat and nasal or sinus congestion.
Some people suffering from these syndromes can tolerate cooked or canned kiwi, since heating changes the shape of the proteins and reduces cross-reactivity reactions.
People with a history of calcium oxalate kidney stones may also want to avoid eating the skin of the kiwi, since it’s higher in oxalates than the inner flesh of the fruit.
Oxalates can bind with calcium in the body and form painful stones in the kidneys of those predisposed to this condition.
While not all research has shown benefits from reducing oxalate intake, it’s recommended by the American Urological Association for the management of kidney stones.
Summary: People with kiwi allergies, oral allergy syndrome, latex food allergies or a history of kidney stones may want to avoid eating kiwis and the skin.
Kiwis are good for you
Whether or not you choose to eat the skin, consuming the fruit of a kiwi is associated with a variety of health benefits, including:
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- Improved cholesterol levels: Consuming two kiwis per day for eight weeks increases heart-healthy HDL cholesterol levels, boosts antioxidant levels in the blood and decreases dangerous oxidation of LDL cholesterol.
- Lower blood pressure: Eating 3 kiwis per day has been shown to lower blood pressure by an average of 10 points in 8 weeks in some studies.
- Better iron absorption: Pairing kiwifruit with iron-rich foods can increase iron absorption and help correct iron deficiency.
- Increased immunity: Eating kiwi is associated with improved immunity and may help reduce head congestion and sore throat.
- Improved digestion: Kiwi contains an enzyme called actinidin that may help your body more easily digest proteins in your food.
- Reduced constipation: The fiber in kiwifruit can help reduce constipation and ease bowel movements when consumed twice per day.
These studies used the flesh of the kiwi, but it’s reasonable to believe that the same health benefits can be had from eating fruit with the skin.
Summary: Regularly eating kiwifruit is associated with many health benefits, especially a lower risk of heart disease and improved bowel movements.
Tips for selecting, preparing and storing kiwis
Kiwis are a hardy fruit that can last for a long time when properly selected, prepared and stored.
How to select a kiwi
If you plan on eating the kiwi skin, look for smaller fruits, as they tend to have more tender skin than larger varieties.
While green kiwis are the most commonly sold variety, golden kiwifruit are new on the US market. They have sweet yellow flesh and fuzz-free skin.
Kiwi grapes, a miniature smooth-skinned type of fruit, can also be enjoyed whole.
Look for fruit with smooth, blemish-free skin that gives slightly when pressed. If the kiwi is extremely firm, it’s underripe, but if it feels mushy, it’s overripe.
Some research suggests that organic kiwis may have more antioxidants than conventionally grown fruits, so you may want to choose organic when available.
How to prepare kiwis
Wash the outside of the kiwi before eating to remove any dirt, germs or pesticides.
Soaking the fruit for 15 minutes in a mixture of baking soda and water may help remove more residue than rinsing with water alone.
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Kiwis are generally considered low in pesticide residues, but washing them is still a good idea since the fruit may have picked up other contaminants during processing, packaging or transport.
How to store kiwis
Kiwis are typically harvested when they are not yet ripe, and continue to ripen during storage.
The ripening process slows under cold temperatures, so kiwis should be ripened at room temperature and then moved to the refrigerator once they’re ready to eat.
Once refrigerated, they can last up to four weeks.
Summary: Select kiwis that are firm and blemish-free, wash them well before consuming and refrigerate the fruits once they’re ripe.
Kiwis are a delicious and nutritious fruit choice for most people.
While the skin is perfectly edible and provides lots of fiber, folate and antioxidants, some people dislike its texture.
There are many varieties of kiwi to choose from, including several with tender, fuzz-free skin, so you can experiment and find your favorite type.
People with sensitive mouths, kiwi allergies or a history of kidney stones should avoid eating the fruit and its skin, since it can exacerbate these conditions.
Regular kiwi consumption is associated with many health benefits, including better immunity, a lower risk of heart disease and improved digestive health, so it may be wise to include them in your diet.