Know2eat

Cucumber

Cucumis sativus

What cucumber has been studied for

2 associations assessed — none with dependable human evidence behind them yet. Strongest first.

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

About cucumber

A watery cucurbit fruit eaten as a vegetable, usually raw. The USDA reference here includes the peel, which carries most of what little nutrient content the fruit has.

Also known as Slicing cucumber, English cucumber, Gherkin (immature), Khira

Heart HealthSkin Health

The evidence in depth

Best supported: Insufficient

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.

Healthy blood pressure

Heart Health
Insufficient evidence

Cucumber water and cucumber juice are widely promoted for blood pressure. There is essentially no controlled human research, and the potassium content of a realistic serving is unremarkable.

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

2 sources

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

Skin structure and hydration

Skin Health
Insufficient evidence

Cucumber is probably the most heavily associated food in the world with skin appearance, almost entirely because slices are cool and slices are round. There is no human research showing that eating cucumber changes skin hydration, elasticity or ageing.

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

2 sources

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

Ask about Cucumber

Ask about Cucumber

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
Calories15 kcal1%
Protein0.65 g1%
Total fat0.11 g0%
Carbohydrate3.63 g1%
Fibre0.5 g2%
Total sugars1.67 g—
Water95.2 g—
Fats
Saturated fat0.037 g0%
Monounsaturated fat0.0050 g—
Polyunsaturated fat0.032 g—
Cholesterol0 mg0%
EPA (omega-3)0 g—
DHA (omega-3)0 g—
DPA (omega-3)0 g—
Linoleic acid (omega-6)0.028 g—
Vitamins
Vitamin A5 µg1%
Vitamin C2.8 mg3%
Vitamin D0 µg0%
Vitamin E0.03 mg0%
Vitamin K16.4 µg14%
Thiamin (B1)0.027 mg2%
Riboflavin (B2)0.033 mg3%
Niacin (B3)0.098 mg1%
Pantothenic acid (B5)0.259 mg5%
Vitamin B60.04 mg2%
Folate7 µg2%
Vitamin B120 µg0%
Choline6 mg1%
Minerals
Calcium16 mg1%
Iron0.28 mg2%
Magnesium13 mg3%
Phosphorus24 mg2%
Potassium147 mg3%
Sodium2 mg0%
Zinc0.2 mg2%
Copper0.041 mg5%
Manganese0.079 mg3%
Selenium0.3 µg1%
Other measured compounds
Beta-carotene45 µg—
Alpha-carotene11 µg—
Lycopene0 µg—
Lutein + zeaxanthin23 µg—
Caffeine0 mg—
Ash0.38 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: Cucumber, with peel, raw (USDA FoodData Central, FDC ID 168409).

% 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.

  • rawPreserves peel polyphenols and vitamin K

    Most of the small nutrient content of a cucumber is in the skin. Peeling removes it, which is a reasonable trade if the skin is waxed or bitter and a needless loss otherwise.

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

    Bitter cucumbers and cucurbitacins

    Cucumbers stressed by heat or drought can produce cucurbitacins, concentrated at the stem end and in the peel. They taste unmistakably bitter and cause stomach upset. Modern varieties are largely bred free of them, but a bitter cucumber should still be discarded.

  • Worth knowing

    Nutritionally close to water

    Cucumber is around ninety-six per cent water. That makes it excellent for bulk and hydration and a poor source of essentially every nutrient, which is worth being clear about given how it is marketed.

  • Allergy

    Ragweed-related oral allergy syndrome

    Cucumber and melon cross-react with ragweed pollen. People sensitised to ragweed commonly report itching or tingling of the lips and mouth with raw cucumber, which usually disappears if it is cooked.