What is kiwi?
Kiwis, also known as kiwifruit, are a type of fruit native to the mountains and hillsides of Southwest China.
They’re now grown in many other areas of the world, including New Zealand, which is a top producer of this popular fruit. Kiwis are also grown in many other areas of the world, including the United States.
Kiwis were first brought to New Zealand in 1904 by a schoolteacher named Isabel Fraser, who brought kiwi seeds back home with her after traveling through China.
Once known as Chinese gooseberry, kiwis were given the name “kiwi” by New Zealand fruit exporters after the flightless kiwi birds, which are endemic to New Zealand.
Botanically, kiwis are classified as berries. Actinidia deliciosa and A. chinensis are the two most commonly consumed kiwi species.
The most popular type of A. deliciosa kiwi is the Hayward kiwi, a green kiwi named after a man named Hayward Wright, who popularized kiwis in New Zealand in the 1920s.
Hayward kiwis are oval in shape and about the size of a large hen’s egg. They have fuzzy brown skin, green flesh, and tiny black seeds.
Kiwis also come in yellow-fleshed or golden varieties (A. chinensis). The difference between green-fleshed and yellow-fleshed kiwis is that green kiwis contain a green pigment called chlorophyll while yellow kiwis do not.
It should be noted that kiwis are not the same species as kiwiberry. Even though they belong to the same plant family, Actinidia, kiwiberries are small and have edible, grape-like skin.
Kiwis are larger and have thicker, fuzzy skin.
The skin of most varieties of kiwi should be peeled off before you eat them. However, some people like to eat the skin of golden or yellow kiwi varieties because the skin is softer than the skin of green kiwis.
Kiwis have an impressive nutrient profile.
Here is the nutrition breakdown for a 3.5 ounce (100-gram) serving of the flesh of a raw, green kiwi:
Kiwis are exceptionally high in vitamin C, with a 3.5-ounce (100-gram) kiwi providing over 80% of the average daily vitamin C needs.
Vitamin C functions as a powerful antioxidant in the body, protecting cells against oxidative damage. It’s also involved in immune function and your body needs it to make collagen and neurotransmitters.
Additionally, kiwis contain potassium, copper, vitamin K, folate, and vitamin E, a fat-soluble nutrient that has antioxidant effects and plays an important role in immune health.
Kiwis are low in calories, protein, and fat, and they’re a good source of fiber.
According to research findings, kiwis may benefit health in the following ways.
1. Excellent source of beneficial plant compounds
In addition to containing the antioxidant nutrients vitamin C and vitamin E, kiwis are an excellent source of plant compounds that have antioxidant and anti-inflammatory effects in the body.
For example, kiwis contain carotenoids, which have health-promoting properties. These compounds include:
Studies show that diets high in carotenoids may help protect against certain health conditions, including heart disease.
A review of 69 studies found that higher dietary intake and higher blood concentrations of carotenoids, vitamin C, and vitamin E were associated with a lower risk of heart disease, total cancer, and death from all causes.
Kiwis are rich in all these nutrients.
Plus, a study that included data on over 17,000 adults found that those whose diets were rich in total carotenoids had a lower risk of depressive symptoms.
Kiwis also contain polyphenol compounds, like caffeic acid and chlorogenic acid, which exert anti-inflammatory effects in the gut and throughout the body.
Some research suggests that the total antioxidant capacity of kiwis are higher than many popular fruits, including apples, grapefruits, and pears.
2. May benefit heart health
Consuming a diet rich in vegetables and fruits like kiwis is a smart way to support heart health.
Studies show that eating kiwis, specifically, could help reduce heart disease risk factors, including high blood pressure.
A study looked at the effects of eating either kiwis or apples in 118 people with either high normal blood pressure or stage one high blood pressure.
Those who ate three kiwis per day for 8 weeks had lower blood pressure at the end of the intervention compared with those who ate one apple per day.
A 2012 study in 102 men who smoked had participants eat three kiwis per day for 8 weeks. Those who did this had reductions in blood pressure and platelet aggregation, or the clumping together of platelets in the blood, compared with a control group.
Platelet hyperactivity could increase the risk of heart disease because platelets can stick to blood vessel walls, forming plaques. When this happens, it’s a condition known as atherosclerosis.
People who smoke are at higher risk of plaque buildup, so eating kiwis may help prevent platelet accumulation and reduce the risk of atherosclerosis in this population.
What’s more, some studies have shown that eating kiwis may help reduce total cholesterol and triglycerides and boost heart-protective HDL (good) cholesterol.
It’s worth noting that adding any fresh or frozen fruit to your diet, not just kiwis, is likely to benefit your heart health. Nonetheless, eating kiwis is a delicious way to take care of your heart.
3. Benefits digestive health
Kiwis contain both insoluble and soluble fiber. Studies show that kiwis contain about one-third soluble and two-thirds insoluble fiber.
The soluble fiber found in kiwis may benefit blood sugar regulation and heart health and help support healthy gut bacteria, while the insoluble fiber found in the fruit can help keep bowel movements regular.
The fiber found in kiwis can retain water and swell more than other types of fibers, like apple fiber and wheat bran, which means it’s a good choice for improving stool consistency and decreasing the time it takes for food to go through your digestive system.
Because of these qualities, kiwis may be a good choice for people who have constipation.
In fact, a study in 79 people with chronic constipation found that eating two kiwis per day for 4 weeks helped improve stool consistency and frequency and helped decrease straining during bowel movements.
Also, more participants were satisfied with the kiwi treatment compared with consuming psyllium husk or prunes. The kiwi treatment was also associated with the lowest rate of adverse side effects out of the three treatments (15).
4. Excellent source of vitamin C
Kiwis are exceptionally high in vitamin C, a nutrient that helps protect your cells from oxidative damage and plays many other important roles in the body.
Studies show that eating kiwi can help you reach optimal blood levels of vitamin C.
A 2012 study in 15 males with low vitamin C levels demonstrated that eating one kiwi per day for 6 weeks was enough to reach “healthy” vitamin C levels, while eating two kiwis per day resulted in vitamin C saturation, or the highest that vitamin C levels can reach.
Other older studies have also found that daily kiwi intake is effective for increasing vitamin C levels in the body.
What’s more, older studies suggest that the bioavailability of the vitamin C found in kiwis is the same as vitamin C supplements, making kiwis an excellent alternative to supplement pills.
Maintaining optimal vitamin C levels is critical for immune function.
In fact, a study showed that eating two kiwis per day for 4 weeks increased vitamin C levels and also improved the function of immune cells called neutrophils in young men with low vitamin C levels.
Neutrophils are white blood cells that help protect against pathogens and infection. These cells accumulate high concentrations of vitamin C, which is thought to protect these cells and support their functioning.
For this reason, eating foods rich in vitamin C like kiwis can help promote optimal immune function.
Eating kiwis regularly is beneficial for health and does not pose any risks for most people.
The main exception is for those who have a kiwi allergy.
Kiwis contain many potential allergens, including actinidin, which is kiwi’s major allergen.
Kiwis can cause minor to severe allergic reactions in some people, particularly in children.
Signs of a kiwi allergy include:
How to eat kiwi
Many people enjoy eating kiwis raw. You can also incorporate them into a number of recipes, both sweet and savory.
Most species of kiwi should be peeled before you eat them. However, some particular varieties, including Zespri SunGold kiwis, can be eaten whole, including the outer peel.
You can enjoy kiwis on their own or add them to dishes like fruit salads.
Here are a few ways to use them:
There are many other ways to use kiwi in the kitchen. Try experimenting with kiwi in your favorite sweet and savory recipes.