Health Benefits and Side Effects of Kiwis

Kiwis, with their vibrant green flesh and unique flavor, are not only a delicious treat but also offer an array of health benefits. Packed with essential nutrients, vitamins, and antioxidants, kiwis have gained recognition as a superfood. However, it is important to understand the potential risks associated with their consumption. In this article, we delve into the health benefits and potential risks of kiwis, shedding light on their nutritional profile and discussing their impact on overall well-being.

What is Kiwi?

Kiwi, also known as kiwifruit or Chinese gooseberry, is a small fruit with a fuzzy brown exterior and vibrant green flesh. It originated in China and was later introduced to New Zealand, where it got its name “kiwi” due to its resemblance to the country’s national bird. Kiwi is known for its unique taste, combining sweetness with a slightly tart and tangy flavor.

Kiwis are often consumed as a fresh fruit, either by cutting them in half and scooping out the flesh or by peeling the skin and slicing the fruit. They can be enjoyed on their own, added to fruit salads, blended into smoothies, or used as a topping for desserts and yogurt. Kiwis are versatile and can complement both sweet and savory dishes, adding a vibrant touch to various culinary creations.

Kiwi Nutrition

Kiwis have an impressive nutrient profile. Here are the nutrient facts for 100 grams (3.5 ounces) of kiwi fruit:

• Calories: 61
• Carbohydrates: 15 grams
• Fiber: 3 grams
• Protein: 1.1 grams
• Fat: 0.5 grams
• Vitamin C: 93% of the Daily Value (DV)
• Vitamin K: 38% of the DV
• Vitamin E: 6% of the DV
• Potassium: 4% of the DV
• Folate: 4% of the DV

Additionally, kiwi fruit contains small amounts of other vitamins and minerals such as vitamin A, vitamin B6, calcium, iron, magnesium, and phosphorus. It’s worth noting that the nutrient content can vary slightly depending on the size and ripeness of the kiwi fruit. However, kiwis are generally considered a nutrient-dense fruit, especially due to their high vitamin C content, which is significantly higher than that of many other fruits. They also provide a good amount of dietary fiber, which aids in digestion and supports overall health.

Health Benefits of Kiwi

According to research findings, kiwis may benefit health in the following ways:

Rich in Antioxidants:

kiwis are a good source of antioxidants. Antioxidants are substances that can help protect your cells from damage caused by free radicals. Free radicals are unstable molecules that can damage cells and contribute to the development of chronic diseases such as cancer and heart disease. Kiwis contain several different types of antioxidants, including:

• Vitamin C: Vitamin C is a powerful antioxidant that helps protect cells from damage. One cup of kiwifruit provides 273% of the recommended daily intake of vitamin C.
• Vitamin E: Vitamin E is another powerful antioxidant that helps protect cells from damage. One cup of kiwifruit provides 12% of the recommended daily intake of vitamin E.
• Flavonoids: Flavonoids are a type of antioxidant that is found in many fruits and vegetables. Kiwis contain several different types of flavonoids, including quercetin, kaempferol, and rutin.
• Carotenoids: Carotenoids are a type of antioxidant that gives fruits and vegetables their bright colors. Kiwis contain several different types of carotenoids, including beta-carotene, lutein, and zeaxanthin.

The antioxidants in kiwis can help protect your cells from damage and reduce your risk of developing chronic diseases.

Improves Heart Health:

Studies show that eating kiwis could help reduce heart disease risk factors, including high blood pressure and high cholesterol. 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. The participants ate three kiwis or one apple per day for eight weeks. The results showed that the kiwi group had significantly lower systolic and diastolic blood pressure than the apple group. The kiwi group also had lower levels of blood clotting factors and oxidative stress markers than the apple group. Another study compared the effects of eating two kiwis or two bananas per day for 28 days in 38 people with mildly elevated cholesterol levels. The results showed that the kiwi group had significantly lower total cholesterol, LDL (bad) cholesterol, and triglycerides than the banana group. The kiwi group also had higher HDL (good) cholesterol and antioxidant capacity than the banana group. The researchers suggested that the high vitamin C, polyphenol, and fiber content of kiwis may be responsible for these beneficial effects on heart health.

Enhances Digestion:

Kiwis may also help improve digestion and prevent constipation. Kiwis are a good source of fiber, which adds bulk to stools and promotes regular bowel movements. Fiber also feeds the beneficial bacteria in the gut, which may improve gut health and immunity. Kiwis also contain a unique enzyme called actinidin, which helps break down proteins in food and may enhance protein digestion. Actinidin may also help reduce bloating, gas, and abdominal discomfort after eating. A study examined the effects of eating two green kiwis per day for four weeks in 41 people with irritable bowel syndrome (IBS). The results showed that the kiwi group had significantly improved bowel function, reduced constipation, and increased stool frequency and softness than the control group. Another study compared the effects of eating two green kiwis or two golden kiwis per day for six weeks in 32 healthy adults. The results showed that both types of kiwis increased stool frequency and improved stool consistency compared with baseline. However, only green kiwis reduced colonic transit time (the time it takes for food to pass through the colon).

Boosts Immunity

Kiwis may also help boost immunity and prevent infections. Kiwis are rich in vitamin C, which is a vital nutrient for immune health. Vitamin C helps stimulate the production and function of white blood cells, which fight off pathogens and foreign invaders. Vitamin C also enhances the activity of natural killer cells, which destroy infected or cancerous cells. Kiwis also contain other antioxidants, such as vitamin E, polyphenols, and carotenoids, which help protect immune cells from oxidative damage and inflammation. Kiwis also provide prebiotic fiber, which nourishes the gut microbiome and supports immune system balance. A study investigated the effects of eating four gold kiwis per day for four weeks in 32 healthy older adults. The results showed that the kiwi group had significantly higher levels of vitamin C, vitamin E, and natural killer cell activity than the control group. The kiwi group also had lower levels of oxidative stress markers and inflammation markers than the control group. Another study evaluated the effects of eating three gold kiwis per day for 16 weeks in 132 healthy older adults. The results showed that the kiwi group had significantly fewer episodes of upper respiratory tract infections (URTI), such as colds and flu, than the control group. The kiwi group also had shorter duration and severity of URTI symptoms than the control group.

Supports Skin Health:

Kiwis may also help improve skin health and appearance. Kiwis are rich in vitamin C, which is essential for collagen synthesis. Collagen is a protein that provides structure and elasticity to the skin. Collagen production declines with age, leading to wrinkles and sagging skin. Vitamin C may help prevent or reduce these signs of aging by stimulating collagen formation and protecting skin cells from oxidative damage. Kiwis also contain vitamin E, which helps moisturize and nourish the skin. Vitamin E also protects the skin from sun damage and inflammation. Kiwis also provide antioxidants, such as polyphenols and carotenoids, which may help prevent or reverse skin damage caused by free radicals, UV rays, pollution, and stress. A study examined the effects of eating two gold kiwis per day for 12 weeks in 54 healthy young women. The results showed that the kiwi group had significantly improved skin hydration, smoothness, elasticity, and radiance than the control group. The kiwi group also had lower levels of skin redness and melanin (pigment) production than the control group.

Cancer Prevention:

Kiwi is a rich source of vitamin C, polyphenols, and carotenoids, which are antioxidants that help remove free radicals from the body, which is one way in which the fruit may help prevent cancer. Free radicals are unstable molecules that can damage the DNA and cause mutations that can lead to cancer. Antioxidants can neutralize free radicals and protect the cells from oxidative damage and inflammation.

Kiwi may also help repair damaged DNA and prevent cancer cell growth. Kiwi contains actinidin, a unique enzyme that can help break down proteins and peptides that may interfere with DNA repair and cell cycle regulation. Kiwi also contains phytonutrients, such as quercetin, kaempferol, and catechin, which can modulate the expression and activity of genes and enzymes involved in apoptosis (programmed cell death), angiogenesis (blood vessel formation), metastasis (cancer spread), and immune response.

Kiwi may also have beneficial effects on other factors that influence cancer risk and progression, such as obesity, blood pressure, cholesterol, blood sugar, and gut health.

Bone Health:

Kiwi is a rich source of vitamin C, vitamin K, copper, and magnesium, which are nutrients that are important for bone health. Vitamin C helps synthesize collagen, which is a protein that provides structure and strength to bones. Vitamin C also enhances the absorption of calcium, which is a mineral that is essential for bone mineralization. Vitamin K helps regulate calcium levels in the body and may prevent calcification of arteries. Vitamin K also activates osteocalcin, which is a protein that binds calcium to bones. Copper helps form cross-links between collagen and elastin, which are proteins that provide flexibility and resilience to bones. Copper also acts as a cofactor for several enzymes involved in bone metabolism and antioxidant defense. Magnesium helps maintain bone density and structure by regulating calcium transport and deposition in bones. Magnesium also modulates the activity of osteoblasts (bone-forming cells) and osteoclasts (bone-resorbing cells). – Kiwi may also have anti-inflammatory and antioxidant effects, which may protect bones from damage and inflammation.

Asthma:

Kiwi is a rich source of vitamin C, which is a potent antioxidant that can protect the lungs from oxidative damage and inflammation caused by environmental pollutants, allergens, and infections. Vitamin C can also modulate the immune system and reduce the production of histamine, which is a mediator of allergic reactions and bronchoconstriction. Vitamin C may also enhance the effects of corticosteroids, which are anti-inflammatory drugs used to treat asthma.

Kiwi also contains other antioxidants, such as polyphenols and carotenoids, which may have anti-inflammatory and anti-allergic effects. Polyphenols can inhibit the activation of mast cells, which are immune cells that release histamine and other inflammatory mediators. Carotenoids can modulate the expression of genes involved in inflammation and immunity. Kiwi also contains actinidin, a unique enzyme that may help reduce mucus production and viscosity, which can improve airway clearance and reduce coughing.

Kiwi may also have beneficial effects on other factors that influence asthma risk and severity, such as obesity, blood pressure, cholesterol, blood sugar, and sleep quality. Kiwi may help prevent or treat obesity, which is a risk factor for asthma and can worsen asthma symptoms and control.

Blood Sugar:

Kiwi is a low-glycemic fruit, meaning it does not raise blood sugar quickly or significantly. It has a glycemic index of 50 and a glycemic load of 7, which are both in the moderate range. Kiwi is also rich in fiber, which helps slow down the absorption of sugar and prevent spikes and crashes in blood sugar levels.

Kiwi may also help improve insulin sensitivity and glucose uptake in the cells. Kiwi may help boost insulin sensitivity by providing vitamin C, polyphenols, and actinidin. Vitamin C is an antioxidant that can protect the cells from oxidative stress and inflammation, which can impair insulin signaling. Polyphenols are plant compounds that can modulate the expression and activity of genes and enzymes involved in glucose metabolism. Actinidin is a unique enzyme that can help break down proteins and peptides that may interfere with insulin action.

Health Risks of Kiwi

Eating kiwis is generally safe for most people. However, some people may experience allergic reactions or other adverse effects from eating kiwis. Some common symptoms of kiwi allergy include:

• Itching or tingling in the mouth or throat
• Swelling of the lips, tongue, or face
• Hives or rash
• Difficulty breathing or swallowing
• Nausea or vomiting
• Diarrhea or abdominal pain
• Anaphylaxis (a severe allergic reaction that can be life-threatening)

Kiwi allergy is more common in people who are allergic to other fruits or plants in the same family, such as latex, bananas, avocados, chestnuts, or figs. This is because these plants share some proteins that can trigger cross-reactivity. People who are allergic to birch pollen may also react to kiwis due to a phenomenon called oral allergy syndrome. If you have a known or suspected allergy to kiwis or any of the related plants or pollen, you should avoid eating kiwis or consult your doctor before trying them. If you experience any signs of an allergic reaction after eating kiwis, you should seek immediate medical attention.

How to Eat Kiwi

Kiwis are versatile fruits that can be enjoyed in various ways. Here are some tips on how to eat kiwi:

• Choose ripe kiwis that are firm but yield to gentle pressure. Avoid kiwis that are shriveled, bruised, or moldy.
• Wash the kiwis under running water and dry them with a paper towel.
• Cut the kiwis in half and scoop out the flesh with a spoon. Alternatively, you can peel off the skin with a knife or a vegetable peeler and slice or dice the flesh.
• Eat the kiwis as they are or add them to salads, smoothies, yogurt, oatmeal, cereal, or desserts.
• You can also make kiwi jam, juice, sauce, salsa, chutney, or sorbet.
• You can store unripe kiwis at room temperature for up to a week or in the refrigerator for up to two weeks. You can store ripe kiwis in the refrigerator for up to a week or in the freezer for up to six months.

Summary

Kiwis are small fruits that have a lot of health benefits. They’re rich in vitamin C, vitamin E, vitamin K, folate, copper, potassium, magnesium, and antioxidants. They may help improve heart health, digestion, immunity, and skin health. However, some people may be allergic to kiwis or experience digestive issues from eating them. Kiwis are also acidic and can damage your teeth if eaten too often or in large amounts. Kiwis are easy to eat and can be added to various dishes. They’re delicious, nutritious, and colorful fruits that can brighten up your day and your diet.

Disclaimer: Tips and suggestions mentioned in the article are for general information purposes only and should not be construed as professional medical advice. Always consult your doctor or a dietician before starting any fitness programme or making any changes to your diet.