What Are the Benefits of Kumquats and Can You Eat Them Raw?

  • Medical Reviewer: Mahammad Juber, MD
Medically Reviewed on 8/24/2022

What are kumquats?

A kumquat is a small, bite-sized fruit slightly bigger than a grape. The benefits of kumquats include that it supplies antioxidants, boosts immunity, and reduces stress and you can eat them raw.
A kumquat is a small, bite-sized fruit slightly bigger than a grape. The benefits of kumquats include that it supplies antioxidants, boosts immunity, and reduces stress and you can eat them raw.

A kumquat is a small, bite-sized fruit slightly bigger than a grape. It is a citrus fruit that looks like a tiny, oval-shaped orange. It is juicy, sweet, and tart, which makes it ideal for flavoring drinks, jams, marmalades, and more. 

Here’s everything you need to know about kumquats' nutritional value and health benefits. 

Kumquats are juicy citrus fruits that come from China. In Cantonese, kumquat means golden orange, combining the words “kam,” meaning golden, and “kwat,” meaning orange. They are often called “the little gold gems of the citrus family.” 

Kumquats also grow in Japan and Taiwan. In the 1800s, they were introduced to Europe and the U.S. In the U.S., they grow in warmer areas like Florida and California. Unlike other citrus fruits, they can survive in a moderately cold climate.

A kumquat looks like a 1- or 2-inch long, oval orange. Its scientific name is Citrus japonica (formerly known as Fortunella japonica). Unlike other citrus fruits, kumquat has a sweet rind or peel that you can eat. It has sweet and tart flesh. Sometimes, it can be very sour. It may have some seeds, which are bitter. 

There are many types of kumquats. Popular ones include: 

  • Hong Kong. Hong Kong kumquats grow in China. They have an orange-red peel and are less fleshy.
  • Nagami. Nagami kumquats are oval and sour to taste. They are the most common type of kumquat in the U.S.
  • Marumi. Marumi kumquats are plump, round, and golden orange. They grow in Florida and Japan.
  • Meiwa. Meiwa kumquats are sweet, round, and fleshy. They commonly grow in China and Japan. 

What is the nutritional value of kumquats?

Like other citrus fruits, kumquats are rich in fiber and vitamin C. The nutrition in 100 grams of raw kumquats or five kumquats includes:

  • 71 calories
  • 0.9 grams of fat
  • 16 grams of carbohydrates
  • 6.5 grams of dietary fiber
  • 43.9 milligrams of vitamin C
  • 9.4 grams of sugar      
  • 1.9 grams of protein 
  • 62 milligrams of calcium
  • 0.9 milligrams of iron 
  • 10 milligrams of sodium 
  • 186 milligrams of potassium

Kumquats are also rich in vitamin A, thiamine, riboflavin, niacin, pantothenic acid, vitamin B6, vitamin B12, and vitamin E. They also contain mineral micronutrients zinc and selenium. They are rich in antioxidants called carotenoids like beta-cryptoxanthin, lutein, and zeaxanthin. Kumquat also has unsaturated or good fatty acids called omega-3 fats. Along with these nutrients, the high water and fiber content of kumquats make them a healthy snack.

What are the health benefits of kumquats?

Kumquats were in traditional medicine because of their therapeutic value. Their rich nutrition profile makes them good for your health. 

Here are some potential health benefits of kumquats:

Antioxidant activity

Kumquats are rich in antioxidants like vitamins A, C, and E. They also contain phenolic compounds called flavonoids like glycosides and carotenoids like lutein, zeaxanthin, and cryptoxanthin. These substances protect your cells from oxidative damage by harmful molecules called free radicals. 

Free radicals can cause cell aging and damage, which increases your risk of developing chronic diseases like heart problems and cancer. Antioxidants hunt down free radicals, eliminate them, and protect your cells from aging and illness.

A study showed that the juice of ripe kumquats has good antioxidant activity. However, another study showed that raw kumquat peel has more antioxidant potency than its pulp. You can eat raw kumquats or juice them to gain their antioxidant benefits.

Boosts the immune system and reduces stress

Kumquats contain organic substances like beta-cryptoxanthin and limonene. They are responsible for stimulating a type of immune cell called natural killer cells. Natural killer cells are white blood cells that protect your body from damage, infectious diseases, and cancer growth. However, free radical damage, aging, and stress can reduce the levels of natural killer cells in your body and affect your immunity.

Recently, scientists extracted beta-cryptoxanthin and limonene from kumquat peel and studied their effects in mice and human cells. Research revealed that these compounds activate and improve the production of natural killer cells. Limonene additionally had anti-stress effects in mice. If you eat kumquats, these compounds may also improve your immunity and benefit your health. 

Has antimicrobial activity

Lab studies show that the kumquat essential oil has antimicrobial effects. The essential oil extracted from kumquat peel contains organic substances like dihydrochalcones, flavonoids, fortunellin, acacetin, rhoifolin, and poncirin. These compounds have antibacterial and antifungal properties.  

In a study, kumquat essential oil was extracted in hot water using the process of hydrodistillation. The organic compounds in the extract showed antimicrobial activity against harmful bacteria and fungi. Scientists also tested kumquat extract’s antimicrobial effects for the preservation of foods like meat. Results suggest that essential oils distilled from kumquats can be used as natural preservatives in the food industry.

Has potential anticancer effects  

Cancer is one of the leading causes of death in the U.S. It occurs due to various factors, including oxidative damage to the cells and DNA. When your DNA gets affected, it causes changes or mutations in cells. They can make your cells cancerous. 

Protecting your cells from stress and oxidative damage can help prevent cancer. Evidence suggests that including foods rich in antioxidants, like kumquats, in your diet can reduce cancer risk. Scientists studied the anticancer effects of kumquat pulp on Burkitt lymphoma — a type of blood cancer. 

Results revealed that the phenolic compounds in kumquat pulp improved DNA repair and showed potential anticancer effects in Burkitt lymphoma cells. 

Another study showed that Nagami kumquat essential oil was effective against prostate cancer cells. Antioxidant phenolic compounds in kumquat oil decreased the levels of inflammatory molecules and slowed down the growth of prostate cancer cells.

The ability of kumquats to boost natural killer cell production also helps prevent cancer cell growth.

Reduces cholesterol levels and blood sugar 

High cholesterol levels in the blood can lead to heart problems and stroke. If cholesterol reacts with harmful free radicals in your blood vessels, it can cause blockages or atherosclerosis

Kumquats contain antioxidants and fiber, which help decrease cholesterol levels. A study in mice showed that the flavonoids extracted from kumquats reduced low-density lipoprotein or bad cholesterol levels in obese mice. So, eating kumquats may help you control your cholesterol levels and prevent heart problems.

The study also showed that mice fed kumquat extract had reduced blood glucose levels. This indicates that kumquats may be a healthy snack for people with diabetes.

Reduces body fat 

Kumquats can be great food for weight loss. They contain high amounts of dietary fiber, which keeps you full for longer and reduces hunger. They also have various antioxidant flavonoids that help reduce fat levels in your body. 

Scientists conducted a study on mice with obesity that were fed a high-fat diet. The mice were then fed kumquat extract to understand its effects on their body. Results showed that the components in kumquat extract regulate metabolism and fat breakdown in the body. Kumquat extract can even be given as a supplement to treat obesity and related metabolic disorders.

Prevents skin pigmentation

Your body has tyrosine inhibitors that prevent your skin from hyperpigmentation or discoloration. It is the same chemical that prevents fruits from browning. Scientists discovered that raw kumquat peel has several flavonoids that have a tyrosine inhibition effect. This means kumquat peel may have anti-aging effects and be good for your skin.

QUESTION

According to the USDA, there is no difference between a “portion” and a “serving.” See Answer

Can you eat raw kumquats?

You can eat kumquats raw. Unlike other citrus fruits, you can eat kumquats whole because they have a sweet peel. Just pop them in your mouth for a burst of sweet and tart flavors. 

You can also squeeze them and enjoy the citrusy juice. If you don’t prefer tart flavors, you can remove the pulp and the bitter seeds and then eat the fruit. You can also eat pickled or candied kumquats.

It's best to roll a kumquat between your hands. It releases the essential oils and mixes the sweet and tart flavors. Also, chewing makes a kumquat taste sweeter. So, the longer you chew it, the sweeter its flavor.

When you purchase kumquats, make sure you select firm ones. You can store them at room temperature for a few days. You could also store them in the refrigerator for up to 2 weeks.

How to add kumquats to your diet?

Raw kumquats are a healthy snack because of their nutritional value and health benefits. But you can add them to your diet in the following ways: 

  • Jellies, jams, and marmalade
  • Dried or candied kumquat slices
  • Juices or smoothies
  • Marinades, sauces, or relishes 
  • Sliced in salads or sandwiches
  • Baked food like bread, cake, pie, or cookies
  • Dessert toppings and garnishes
  • Sliced in boiling water for tea

Other considerations

Make sure you wash the kumquats well before you eat them. The peel may have dirt or germs, which may cause infections. 

Kumquats may cause allergic reactions in people with citrus allergies. So, check with your doctor if you notice any symptoms after eating citrus fruits like kumquats.

Medically Reviewed on 8/24/2022
References
SOURCES:

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American Association of Cancer Research: "Abstract 1288: The potential of Resveratrol and Nagami kumquat extracts in facilitating DNA repair in Raji cells."

Bioscience, Biotechnology, and Biochemistry: "Effect of kumquat (Fortunella crassifolia) pericarp on natural killer cell activity in vitro and in vivo."

Food & Function: "Immunostimulatory effect of kumquat (Fortunella crassifolia) and its constituents, ß-cryptoxanthin and R-limonene."

Have a plant: "Kumquat."

International Journal of Molecular Science: "Chemical Composition and Antimicrobial Activity of the Essential Oil of Kumquat (Fortunella crassifolia Swingle) Peel."

Johns Hopkins Medicine: “Atherosclerosis."

Journal of Food and Drug Analysis: “Phenolic compounds and biological activities of small-size citrus: Kumquat and calamondin."

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Planta Medica: "Inhibition of prostate cancer (LNCaP) cell proliferation by volatile components from Nagami kumquats."

PLoS One: "Effects of Fortunella margarita fruit extract on metabolic disorders in high-fat diet-induced obese C57BL/6 mice."

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