Know2eat

Fennel bulb

Foeniculum vulgare var. azoricum

What fennel bulb has been studied for

2 associations assessed — 1 with at least some human evidence behind it. Strongest first.

  • 1 Limited
  • 1 Insufficient
3 things to know first — allergies, interactions and intake limits

About fennel bulb

The swollen leaf base of Florence fennel, eaten raw in salads or braised until sweet. Its aniseed character comes from anethole, the same compound that dominates fennel seed.

Also known as Florence fennel, Finocchio, Sweet fennel, Bulb fennel

Women's HealthGut & Digestive Health

The evidence in depth

Best supported: Limited

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how impressive the food is. How we rate evidence.

Menopausal symptoms

Women's Health
Limited evidence

Several small randomised trials of concentrated fennel seed preparations report reductions in hot flush frequency, and they have been pooled in reviews. The trials are small and short, the preparations are extracts and capsules rather than the vegetable, and nothing has been tested about eating fennel bulb.

Limited evidence. Early human work, or mostly lab and animal research.

1 source

Deep research mode adds each paper’s own conclusion and stated limitations.

Digestive comfort

Gut & Digestive Health
Insufficient evidence

Fennel appears in herbal mixtures tested for infant colic and for functional gut symptoms, usually alongside several other botanicals, with modest reported improvements. Attributing those results to fennel specifically, still less to the bulb, is not possible from the trials as designed.

Insufficient evidence. Not enough human research to say anything useful yet.

No source is attached to this association yet, so it is rated insufficient by default. It is listed because people commonly ask about it — not because there is evidence for it.

Ask about Fennel bulb

Ask about Fennel bulb

Answers are written only from the entries on this page — the same nutrients, compounds, claims and citations you can read above. Nothing is added from outside the database, and every answer lists what it was built from.

AI explanations are not switched on for this site, so there is nothing to ask here. Everything above is read straight from the database and does not need them.

Key nutrients

Nutrient content per 100 grams
NutrientAmount% DV
Macronutrients
Calories31 kcal2%
Protein1.24 g2%
Total fat0.2 g0%
Carbohydrate7.3 g3%
Fibre3.1 g11%
Total sugars3.93 g—
Water90.2 g—
Fats
Saturated fat0.09 g0%
Monounsaturated fat0.068 g—
Polyunsaturated fat0.169 g—
Cholesterol0 mg0%
EPA (omega-3)0 g—
DHA (omega-3)0 g—
DPA (omega-3)0 g—
Linoleic acid (omega-6)0.169 g—
Vitamins
Vitamin A48 µg5%
Vitamin C12 mg13%
Vitamin D0 µg0%
Vitamin E0.58 mg4%
Vitamin K62.8 µg52%
Thiamin (B1)0.01 mg1%
Riboflavin (B2)0.032 mg2%
Niacin (B3)0.64 mg4%
Pantothenic acid (B5)0.232 mg5%
Vitamin B60.047 mg3%
Folate27 µg7%
Vitamin B120 µg0%
Choline13.2 mg2%
Minerals
Calcium49 mg4%
Iron0.73 mg4%
Magnesium17 mg4%
Phosphorus50 mg4%
Potassium414 mg9%
Sodium52 mg2%
Zinc0.2 mg2%
Copper0.066 mg7%
Manganese0.191 mg8%
Selenium0.7 µg1%
Other measured compounds
Beta-carotene578 µg—
Alpha-carotene0 µg—
Lycopene0 µg—
Lutein + zeaxanthin607 µg—
Caffeine0 mg—
Ash1.05 g—

Nutrient values are per 100 g of the USDA reference entry named on this page and vary with variety, growing conditions, storage and preparation.

Source record: Fennel, bulb, raw (USDA FoodData Central, FDC ID 169385).

% DV uses the FDA Daily Values for adults and children aged 4 and over. A dash means no Daily Value has been established for that nutrient.

Bioactive compounds

Compounds present in meaningful amounts. Presence is banded rather than quantified, because whole-food levels vary enormously with variety, growing conditions, storage and preparation.

How preparation changes things

Only effects with real support are listed. If a preparation method is missing, it is because nothing dependable is documented — not because it makes no difference.

Nothing dependable is recorded about how preparation changes this food’s nutritional properties. Rather than guess, this section stays empty.

Things to know

Allergies, interactions and intake concerns. Every food gets this section — a reference where everything is uniformly good is not a reference.

  • Worth knowing

    Estragole in concentrated fennel preparations

    Fennel contains estragole, which is genotoxic and carcinogenic in rodents at high doses. European regulators have restricted long-term use of fennel seed tea and fennel essential oil, particularly in infants and young children. The vegetable bulb contains far less than the seed or the oil, but the distinction is worth knowing before giving fennel preparations to a baby.

  • Allergy

    Celery-mugwort-spice cross-reactivity

    Fennel belongs to the same family as celery, carrot and parsley and is part of the celery-mugwort-spice syndrome. People allergic to celery or sensitised to mugwort pollen quite commonly react to it.

  • Too much

    Fructans at larger servings

    Fennel bulb carries moderate fermentable carbohydrate. Small servings are usually tolerated on a low-FODMAP diet while a whole braised bulb often is not.