Health Benefits of Fennel Seeds

Medically Reviewed by Dany Paul Baby, MD on September 19, 2022
3 min read

Fennel seeds are a spice harvested from one of several types of herb fennel plant. They have a sweet, powerful flavor that’s similar to licorice. 

Fennel seeds have traditionally been used in Italian cooking. However, they can be used in all types of food, and in recent years, Western culture has opened its doors to creative uses of fennel seeds in recipes. 

In many parts of the world, fennel seeds are used medicinally to treat everything from menstrual cramps to bad gas. Some of these uses have been confirmed by research while others are still being tested. 

Weight Loss

Fennel seeds are sometimes marketed as a weight loss tool. There may be some truth to the claim that fennel seeds can aid in weight loss. 

One early study suggests that eating fennel seeds reduces appetite and significantly reduces overeating at mealtimes. For people with obesity caused by food cravings and overeating, fennel seeds could be helpful. However, further studies are needed to confirm the effect. Check with your doctor before using fennel seeds to help with weight management. 

Cancer Prevention

One of the major compounds found in fennel seeds is anethole, which has been shown to have cancer-fighting properties. 

Research has shown anethole is effective at destroying breast cancer cells and stopping the spread of both breast and liver cancer cells. These studies have not yet progressed past the lab, but initial findings are promising. 

Increase Milk Production for Breastfeeding Women

Breastfeeding women sometimes struggle to create enough milk to meet the demands of their babies. Fennel seeds could help with that problem. Anethole, a major compound found in fennel seeds, has properties that mimic estrogen and may help stimulate milk production. 

Some studies suggest that eating fennel seeds increases prolactin—the hormone that triggers milk production. If you’re breastfeeding and have a low milk supply, you may consider asking your doctor if drinking tea made with fennel seeds could be helpful. 

In addition to their other health benefits, fennel seeds are rich in: 

Nutrients per Serving

1 teaspoon of fennel seeds contains: 

  • Calories: 7
  • Fat: 0 grams
  • Cholesterol: 0 milligrams
  • Carbohydrates: 1 gram
  • Dietary Fiber: 1 gram
  • Sugar: 0 grams
  • Protein: 0.3 grams

Things to Watch Out For

Although whole fennel seeds are safe to eat in moderation, the concentrated levels of chemicals found in many supplements or essential oils may not be as safe. Anethole, one of the major compounds in fennel seeds, has properties similar to estrogen. In large amounts, it can interfere with medications and cause unexpected side effects. 

One study found that when fennel essential oil was used on pregnant rats, it caused their embryos to die. If you are pregnant, consult with your doctor before using fennel seed supplements or essential oils.

One of the major appeals of fennel seeds is that they provide a low-calorie, cholesterol-free flavoring for recipes. They have a sweet, aromatic taste and are traditionally used in curries and Italian food.

There are a number of ways you can use fennel seeds in your cooking. For an extra boost of flavor, try adding them to:

  • Salads
  • Breads
  • Soups and Stews
  • Curries
  • Pastas
  • Desserts

In some parts of the world, it’s popular to eat roasted fennel seeds on their own. Roast them with a little salt or sugar to make a delicious, satisfying snack.