10 Fennel Benefits for Gut Health, Immune Support, and More

Promotes Gut Health

Adults should ideally consume 25 to 30 grams of fiber per day according to the American Heart Association recommendations. A cup of sliced fennel provides you with 10 percent of the recommended DV of fiber. The fiber in fennel seeds have traditionally been used to help relieve bloating, prevent constipation, and regulate bowel movements.

You may link fiber to gut health, and it’s true, Fiber does wonders for maintaining a healthy gut microbiome (the collection of bacteria and other microorganisms living naturally in your gut lining) and for keeping your trips to the bathroom regular and easy.

Controls Blood Pressure

A cup of sliced fennel contains 360 milligrams of potassium, which is 7 percent of the recommended daily value (DV). Potassium is a mineral that helps to keep your blood pressure at a healthy range, says Talia Follador, RDN, LDN, a registered dietitian and the owner of Follador Nutrition Services. It does this by helping blood vessels relax and increasing the amount of sodium the kidney removes from your blood. (Note: If you have kidney disease, be sure to check in with your doctor or dietitian first before consuming too much potassium.)

Strengthens Immune System

Move over citrus fruits—did you know a cup of sliced fennel provides up to 13 percent of the recommended DV of vitamin C? Vitamin C is needed to help build immune cells and strengthen your immunity, in order to prevent or help fight infections, Follador says. The production of collagen, which is what gives your skin its structure and firmness, requires vitamin C, too.

Vitamin C is also an antioxidant and supports the regeneration of other antioxidants in the body. Antioxidants lower the levels of reactive oxygen species, which your body produces just by doing day-to-day activities and from being exposed to things in your environment, explains Mckenzie Caldwell, MPH, RDN, fertility and prenatal dietitian at Feed Your Zest Nutrition & Wellness. According to Follador, excessive levels of reactive oxygen species can damage DNA, weaken the immune system and cause cell breakdown.

Supports Muscles and Bones

Fennel also has smaller amounts of the minerals calcium, magnesium, and iron. “Both calcium and magnesium make up the structure of your bones,” Follador says. “Consuming enough calcium and magnesium can help prevent osteoporosis and promote strong bones.” These minerals also help your heart and muscles contract properly. 

Iron is essential for the formation of red blood cells, which carry oxygen to all parts of your body. According to Follador, not getting enough iron may lead to low levels of red blood cells, which makes it harder for the body to transport oxygen throughout the body and lead to you experiencing tiredness, weakness, or fatigue, so foods with iron are an important part of a healthy diet.

Improves Hormonal Imbalances

Fennel is a phytoestrogen, meaning that it mimics estrogen, a hormone in the body. In menopause, when estrogen levels fall, consuming fennel might be helpful for alleviating some symptoms, Caldwell explains. However, it might not be ideal to consume copious amounts of fennel if you have endometriosis or are pregnant or breastfeeding. “We don't want to mess with the hormones too much in these cases,” Caldwell says.

Satisfies Hunger

Because fennel is full of fiber, it can help you feel full longer. Just one bulb contains 7.25 grams of fiber, which can help fill you up and make your meals more satisfying.

Enhances Skin

Because fennel is so full of vitamin C, it can have amazing benefits for your skin. One cup of sliced fennel (which is about one serving) contains 10.4 milligrams of vitamin C. Based on a recommended 90 milligrams of vitamin C per day for men and 75 milligrams per day for women, that means one cup of fennel makes up about approximately 11.6% of the daily value for men and 13.9% of the daily value for women.

Vitamin C is crucial for collagen production. It helps to keep the skin firm and has anti-inflammatory properties that can help treat certain skin conditions. The more fennel (and vitamin C) you consume, the better off your skin is.

Supports Eye Health

Fennel is a rich source of vitamin A, which is essential for maintaining good vision and preventing age-related eye disorders. In fact one serving (one cup) contains about 41.8 µg of vitamin A retinol activity equivalents (RAE). Men are recommended 900 µg per day, while women are recommended 600 µg (pregnant and breastfeeding people are recommended 770 and 1,300 µg, respectively). So, 41.8 µg of vitamin A equates to about 4.6% of the daily value for men and about 6% for women.

Vitamin A promotes the production of pigments that your eyes need for the retina to work properly. Therefore, consuming fennel can help improve your eye health and keep poor vision from creeping up on you.

Reduces Inflammation

The essential oils in fennel have anti-inflammatory properties. These oils can help reduce inflammation and symptoms of inflammatory diseases. They significantly reduce the activation of human neutrophils (immune cells), shorten calcium influx recovery time, and inhibit the activation of certain signaling proteins in the cells. Alongside cumin, fennel can help treat neutrophilic inflammatory diseases.

Boosts Brain Health

Fennel is full of potassium, folate, and antioxidants that, together, help boost brain function. Potassium, for example, helps to increase blood flow to the brain, which can enhance cognitive function. Meanwhile, folate and antioxidants help reduce the risk of neurodegenerative diseases.