5 Benefits of Kumquats: This High Fiber Food Boosts Your Immune System

The next time you go to the grocery store, you may want to check your produce section for kumquats, which appear to be the miniature offspring of oranges but are actually completely unrelated and arguably more nutrient-dense than everyone's favorite citrus. The grape-sized fruit is worth spending a few extra minutes searching for, since their tiny piles may be nestled near the grapefruit or other citrus orbs.

If you've never tried one, when you bite into a kumquat don't be surprised at the taste, which is bitter at first and then sweet, as the juice kicks in and fills your senses with a distinctly fragrant taste stronger than most citrus. They taste like tropical candy, but without the added sugar. Beyond satisfying your sweet tooth, you'll also reap the tiny kumquat's oversized powerful health benefits.

Kumquats are fully loaded with antioxidants that our bodies need to build stronger immunity and help fight chronic diseases. In particular, the peel of kumquats contains limonene, which helps activate your body's "Natural Killer" (NK) immune cells that work to fight off serious diseases, according to studies. Other citrus peels contain it as well, but you don't eat the peel of orange and grapefruits, whereas you do eat the skin of a kumquat.

Kumquats have been used for centuries in traditional folk medicine in Asia to treat colds and other respiratory symptoms. The powerful immune-boosting compounds fight more than just coldsand flu: They help the body to fight cellular aging and the stress caused by free radicals, two things that also weaken the immune system and can result in chronic diseases.

The tiny olive-sized citrus is most notable for its high vitamin C and fiber content, making this one of the perfect fruits to eat for both immunity and weight loss. Five kumquats, or 100-grams, contain 44 milligrams of vitamin C, which is more than half of the recommended daily amount of C for women (75 mg), and almost half of the recommended daily amount for men (90mg).

Due to their natural ability to rev up the immune system, kumquats have been used for centuries in traditional medicine in Asian countries to treat colds and other respiratory symptoms according to another review study which also pointed out that the fruit has powerful effects on the immune system.

The high fiber content in kumquats also deserves noting. There are 7 grams of fiber in five whole kumquats, an astonishing amount for such a tiny little fruit. For context, 16 kumquats are equal to the recommended daily fiber amount for women (25 grams). In addition, the grape-sized fruit contains 2 grams of protein per 100 grams of kumquats. We're not advising you to chomp on kumquats after a workout to refuel your body, but shockingly enough, the fruit is more nutrient-dense than most other citrus fruits, including oranges.

If weight loss is one of your health goals, kumquats are a diet-friendly food, since they make you feel fuller longer, which helps you avoid unhealthy snacks. To eat more kumquats, enjoy them chopped in a salad or eaten whole with the peel.

Kumquats are known for their rich source of antioxidants, protecting your body against free radicals which are linked to aging and serious diseases, including cancers.

In a study published by the National Library of Medicine, a group of food chemists examined whether drying kumquats would lower their antioxidant effects and found the opposite was true: on the antioxidant activity of kumquats went up during the drying process. so one healthy way of eating the fruit was dried if you are seeking increased levels of antioxidants and flavonoids.

Researchers found out that drying kumquats below 266 degrees Fahrenheit for one hour released more phenolic compounds, natural chemicals that "play a significant role in the prevention of many chronic diseases due to their antioxidant, anti-inflammatory, and anti-carcinogenic properties." Due to this drying process, an "increase of antioxidant activity took place," according to professor Shyi-Neng Lou, Department of Food Science, National Ilan University in Taiwan, and leader of the research group.

Kumquats are often always eaten with the peel, which means you get the benefit of the skin as well. That is significant according to another study, also led by professor Shyi-Neng Lou. This study found that "the total phenolic and flavonoid content of extracts from the peel of kumquat were higher than those from pulp, and those extracted from immature kumquat were higher than those from mature kumquat."

However, one review about kumquats warned that we should " Stay away from greenish, unripe fruits," but did not provide any evidence or data as to why.

Kumquats have a special ability to activate the body's innate immune cells, even beyond what vitamin C can do, according to a study. Specifically, kumquats contain a compound that is able to help the body produce Natural Killer cells (NK), which are powerful immune cells that belong to the family of innate lymphoid cells (ILC) that play an "important role in the innate immune system by eliminating cancer cells and virally infected cells," according to a study published in the National Library of Medicine.

Research shows that the powerful antioxidants and natural killer cells in kumquats play a large role in the prevention of chronic diseases. In a study published by the National Library of Medicine, researchers analyzed the antioxidant count in kumquats and pointed out that the ethanol extracts and essential oils found in kumquats have "antioxidant effects" and protect against "chronic diseases."

As mentioned above, kumquats help activate the body's natural killer (NK) cells that help the immune system by "eliminating cancer cells and virally infected cells," according to a study published in the Food and Function Journal. Because stress and aging reduce the activity of natural killer cells, it's healthy to consume foods that contain these cells to protect your body from disease. The study concluded with: "Our findings suggest that the ingestion of a few kumquats on a daily basis can help to combat stress and enhance NK cell activity."

Kumquats contain a powerful oil called limonene, extracted from the peel. More importantly, limonene "possesses bioactivities such as anti-tumor, antiviral, anti-inflammatory, and antibacterial agents," according to a study published in the National Library of Medicine.

In yet another study published in the PubChem section of the National Library of Medicine,  limonene appeared to have benefits in the lab that helped fight tumor growth: Limonene is a "major component of the oil extracted from citrus rind with chemopreventive and antitumor activities" the study found. Adding to the research on limonene, a different review study concluded that the "biochemical significance of limonene was summarized with emphasis on their antitumor effects."

[Editor's Note: Eating kumquats or any food that has health benefits in the lab is not a treatment for disease or a reason to not pursue medical treatments, so talk with your doctor about any health-related steps you are taking, including your diet.]