12 Health Benefits of Fennel, According to a Nutritionist

Not very familiar with this bulbous seasonal veggie? Here's what to know.

Fennel is one of those vegetables that may be less familiar than, say, broccoli or zucchini. But this bulbous fall veggie and its seeds deserve to be part of your regular vegetable rotation.

Here are some of fennel's nutrients and potential health benefits, what it tastes like, and how to incorporate it into raw and cooked dishes.

Fennel Benefits

Fennel is a nutritious vegetable that:

  • Boasts health-protective nutrients
  • Eases symptoms of menopause
  • Soothes menstrual cramps
  • May promote healthy skin
  • Improves bone health
  • Aids digestion
  • Helps ease pain
  • May aid weight management
  • Helps prevent chronic diseases
  • Supports brain health
  • Prevents anemia
  • Aids eye health

Rich in Health-Protective Nutrients

According to a review in BioMed Research International, fennel has long been used as a medicinal plant for a wide range of conditions related to digestive, endocrine, reproductive, and respiratory systems and as a milk stimulant for lactating mothers. Studies show that fennel contains health-protective antioxidants and valuable antimicrobial, antiviral, anti-fungal, and anti-inflammatory compounds.

One cup of raw fennel slices contains just 27 calories, with nearly 3 grams of fiber. It packs 17% of the daily goal for immune-supporting vitamin C and 10% for blood pressure-regulating potassium, plus smaller amounts of manganese, calcium, iron, and B vitamins.

Eases Symptoms of Menopause

For women, the health benefits of fennel are primarily tied to its oil. A recent paper, published in the Journal of Menopausal Medicine, reviewed the positive effects of fennel oil in the management of painful menstruation, premenstrual syndrome, missing periods, menopause, lactation, and polycystic ovary syndrome.

The report cites one study in which women taking 100 milligrams of fennel oil daily for eight weeks improved their scores on a menopause rating scale, compared with women on a sunflower oil placebo.

However, I don't recommend using essential oils on your own, either orally, topically, or even via aromatherapy. Rely on the guidance and supervision of a physician to determine if you can benefit from oil, which formulation to buy, and how to use it—as well as to monitor any potential interactions, allergic reactions, or other side effects. This is especially true if you're pregnant or trying to conceive. Fennel supplements may also interfere with the effectiveness of birth control pills.

Soothes Menstrual Cramps

Fennel may soothe particularly painful menstrual cramps, which can be helpful if you're menstrual cramps keep you from attending school or work or participating in your daily activities.

That's because fennel may decrease the number of prostaglandins in your body, per one study published in 2012 in the journal Ayu. Prostaglandins are chemicals that help your uterine muscles contract and shed the tissue that lines the inside of your uterus (also called the endometrium). People who have excess prostaglandins may experience more frequent, painful contractions than normal.

Additionally, fennel has nitrites, which aid blood flow, per the Texas Heart Institute. In other words, nitrites may also help the endometrium shed more easily and quickly than normal.

May Promote Healthy Skin

Fennel packs vitamin C, an antioxidant that prevents cell damage caused by free radicals, which are harmful substances that are partly produced by ultraviolet (UV) exposure.

Per the American Academy of Dermatology Association, you should limit your UV exposure in order to decrease your risk of developing skin cancer and premature aging. In addition to wearing an SPF of at least 30, foods that pack antioxidants (like fennel) can help prevent harmful UV exposure.

Improves Bone Health

Fennel is also an excellent source of calcium, which keeps your bones healthy. According to the Johns Hopkins Medicine Health Library, a lack of calcium can increase your risk of developing osteoporosis and bone fractures.

Aids Digestion

The seeds from fennel plants are commonly used as a type of spice to season food. Medicinally, fennel seeds have also been used to treat bloating and gas, via a tea made from a small spoonful of the seeds and hot water, steeped for 20 minutes, and sipped a half hour after a meal.

Helps Ease Pain

A 2020 study, published in Complementary Therapies in Clinical Practice, looked at the effect of fennel in people with knee osteoarthritis. Patients were randomly assigned to receive either capsule containing powdered fennel extract, or a placebo, twice a day for two weeks. The fennel group experienced a reduction in pain and stiffness that was not seen in the control group.

May Aid Weight Management

One of the organic compounds found in fennel, anethole, may naturally suppress appetite, which can be beneficial if you're trying to manage your weight.

In a study published in 2015 in the journal Clinical Nutrition Research, researchers gave nine participants three different teas, one of which included fennel. After the participants consumed the teas, the researchers presented them with a buffet and analyzed the food the participants consumed. All in all, the researchers found that after drinking the teas, the participants experienced less hunger and more feelings of being full.

However, it is important to remember that the sample size of that study is small, and the supposed appetite-suppressing qualities of fennel may not be true for every person.

Helps Prevent Chronic Diseases

The vitamins and minerals and compounds found in fennel may help prevent certain chronic diseases, like cardiovascular diseases and cancer.

For instance, fennel packs a lot of fiber. Per the National Library of Medicine, fiber is one nutrient that can lower your risk of heart disease.

Also, in addition to potential appetite-suppressing qualities, anethole found in fennel links to a lower risk of developing or furthering the growth of cancer. In a study published in 2021 in the journal Scientific Reports, researchers found that anethole helps trigger apoptosis. Apoptosis is programmed cell death, an essential process preventing cancer cells from developing and spreading.

Supports Brain Health

Some research has pointed to fennel helping prevent degenerative diseases, like Alzheimer's disease.

In one study published in 2017 in the journal Natural Product Research, researchers studied the antioxidants found in four herbs, including fennel. After evaluating the herbs, the researchers found that they helped reduce oxidative stress, which damages your cells. Based on their findings, the researchers concluded that fennel is among the herbs that can prevent the onset of Alzheimer's disease.

Prevents Anemia

Iron is one of the main vitamins and minerals found in fennel. According to the National Library of Medicine, iron is an important component of hemoglobin, which is a protein that transports oxygen from your lungs to different parts of your body.

People who have low levels of iron have anemia, a condition that primarily causes weakness and cold hands and feet, among other symptoms. So, because of their iron content, fennel can help replenish some of the iron in your body if you have a deficiency.

Aids Eye Health

Fennel packs a lot of antioxidants that fight eye diseases, like macular degeneration. For example, per a study published in 2013 in the journal Clinical Interventions in Aging, vitamin C—found in fennel—helps form collagen, which is a protein that supports your eyes.

What Fennel Tastes Like

Fennel has a licorice-like aroma, but the fresh bulb is light, bright, and mild. The taste is slightly sweet with a hint of perfumy flavor, but it's delicate and not at all overpowering.

When shopping for fresh fennel, look for a small- to medium-size heavy, intact white bulb that's unbruised, with bright green firm stalks and feathery leaves. Fennel seeds have a stronger anise flavor that's warm and sweet. This is why they're typically used as a seasoning, rather than popping them like sunflower or pumpkin seeds.

Risks of Eating Too Much Fennel

Like all foods, you should enjoy fennel in moderation. Eating too much fennel may expose you to estragole, a carcinogen that may promote the growth of cancer cells. Also, per the National Library of Medicine, some herbs (including fennel) may cause nipple discharge.

Additionally, fennel is a phytoestrogen, meaning that it has plant hormones that act like estrogen. For that reason, fennel may act like a teratogen, having some effects on pregnant people and developing fetuses.

For example, in one study published in 2019 in the Journal of Contemporary Medicine, researchers found that, after experimenting on mice, exposure to fennel during pregnancy affected fetal weight and height.

How To Eat and Cook Fennel

You can eat fennel raw or cooked. I like to shave or thinly slice the bulb and add the shavings to salads along with sliced apples, or marinate in a lemony extra virgin olive oil (EVOO) vinaigrette. To cook fennel, I enjoy sautéing it in EVOO on the stovetop or oven roasting in EVOO that's been simply seasoned with sea salt and black pepper.

Most recipes call for the bulb, but the gorgeous, delicate green tops are also edible. You can mince and use them as a garnish for everything from mashed cauliflower to roasted spaghetti squash and lentil soup. Look for fennel seeds in the spice aisle. Add them to hearty dishes, like lentil Bolognese, potato or white bean soup, or homemade bread.

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