Fennel Nutrition Facts and Health Benefits

Fennel (Foeniculum vulgare) is a vegetable that's starting to catch on in the U.S. Typically associated with Italian or Indian cooking, fennel belongs to the same family as carrots and dill. Fennel is often confused with anise due to their shared licorice flavor. However, fennel is a vegetable completely separate from the similar-tasting herb anise.

You may be familiar with the use of fennel for garnish or spice, but surprisingly, fennel can also serve as the foundation of a meal. Whether eaten raw in salads or cooked as part of a recipe, fennel is a nutritious vegetable worthy of more attention.

Nutrition Facts

The following nutrition information is provided by the USDA for 1 cup (87g) of sliced fennel.

Carbs

Half of the carbohydrates in fennel come from fiber and half come from naturally-occurring sugars. The glycemic index of fennel is 16, making it a very low glycemic food.

Fats

There is very little fat in raw fennel. Cooked fennel also provides hardly any fat aside from what's added while cooking. Although fennel is not a major contributor to total fat intake, the fat it does contain is made up of a wide range of fatty acids. The fatty acids in fennel are largely polyunsaturated (and heart-healthy).

Protein

Fennel is not a high protein food, but you will get a small, 1 gram boost of protein if you consume a full cup serving.

Vitamins & Minerals

Fennel is a good source of potassium, phosphorus, and calcium. When it comes to vitamins, fennel is highest in vitamin C and folate. Fennel also offers essential minerals like manganese, chromium, copper, iron, and zinc.

Health Benefits

Beyond vitamins and minerals, fennel contains a number of phytonutrients and flavonoids known to have antioxidant, anti-inflammatory, and antibacterial properties. These plant compounds contribute to fennel's reputation as a therapeutic agent.

Helps Prevent Cancer

Fennel contains a significant amount of flavonoids, as well as an interesting compound called anethole. Anethole is a free radical scavenger that has been shown to destroy damaged cells before they become cancerous. Its effects have been studied via extraction from fennel's essential oils.

Promotes Dental Health

Chewing on fennel seeds alters the pH balance of the mouth, decreasing the likelihood of dental cavities. Studies show that chewing on fennel seeds for just 10 minutes increases saliva production and produces slight raises in the mouth's pH value. These changes decrease bacterial activity and protect from tooth decay.

Reduces Risk of Heart Disease

As a vegetable, fennel fits perfectly within the recommended guidelines for heart-healthy eating. Not only is fennel naturally free of saturated and trans fats, but its fiber content and antioxidants are also great defenders against cardiovascular disease. Vitamin C has been shown to promote nitric oxide production, which relaxes and opens up the blood vessels through vasodilation. Vasodilation reduces the risk of dangerous blockages.

Supports Breastfeeding

Fennel has been used for centuries by breastfeeding mothers to stimulate lactation. Fennel contains compounds that promote galactogenic activity, including anethole. The neurotransmitter, dopamine, often blocks the hormone responsible for milk production, prolactin. Anethole from fennel competes with dopamine, so lactation is not inhibited.

Improves Digestion

Fennel is often used to treat digestive disorders such as irritable bowel syndrome (IBS), colic, and heartburn. In a trial combining fennel oil with turmeric, the severity of IBS symptoms significantly decreased within 30 days of treatment. Fennel is thought to be responsible for the reduction in abdominal pain.

Allergies

Fennel is not a common allergen, however, allergic reactions are possible. Symptoms of an allergic reaction to fennel include anaphylaxis. Sometimes non-allergic reactions can be confused with allergies. Skin rashes, itchy mouth, or coughing due to inhalation can be mistaken for allergies, but these symptoms are usually signs of intolerance or irritation. See an allergist if you suspect a fennel allergy.

Adverse Effects

Medical experts recommend that if you are taking medications in the fluoroquinolone family, such as ciprofloxacin, you should avoid fennel because it may reduce your body's ability to absorb the drug.

Varieties

Fennel is grown in a few different varieties. Florence fennel is the most common type you'll find in the grocery store. The stalks on Florence fennel are short and green (like celery) with dark green, feathery fronds. The bulb is cream-colored and round. A smaller, more tender version of Florence fennel is called baby fennel or young fennel. Wild fennel, on the other hand, has numerous feathery fronds and a smaller, flatter bulb. You'd be more likely to find young fennel or wild fennel at specialty shops and farmer's markets.

Fennel seeds are also edible and used to add flavor to dishes. Fennel seeds are derived from a bulb-free variety of fennel called common fennel. Common fennel is grown exclusively for harvesting the seeds.

Storage and Food Safety

Choose fennel with firm, intact bulbs that are free of brown spots. The stalks should be straight and relatively close together. Flowers on the stalks of fennel are a sign that it is overripe.

The same general food safety guidelines should be applied to fennel as other vegetables. Wash fennel thoroughly under running water to get rid of dirt and bacteria before cutting into it. Once cut, fennel should be kept cold in the refrigerator and consumed within a few days. Cooked fennel dishes should also be refrigerated and eaten within 5 days.

How to Prepare

Use fennel in recipes to add a savory sweetness to foods, both cooked and raw. Fennel pairs well with seafood and is often used in roasting fish dishes, such as salmon or cod. It's also a favorite in salads for extra texture and flavor. Fennel's mildly sweet anise-flavor can be toned down by slicing the bulb very thinly and soaking in ice water for a few minutes. Although the white bulb of fennel is most commonly eaten, the stalks, seeds, and fronds are also edible.