Know2eat

Rhubarb

Rheum rhabarbarum

What rhubarb has been studied for

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

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

About rhubarb

A vegetable stalk used as a fruit, tart enough that it is almost always cooked with sugar. Only the petiole is food; the large leaf blade is not.

Also known as Garden rhubarb, Pie plant

Gut & Digestive HealthKidney & Urinary 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.

Bowel regularity

Gut & Digestive Health
Insufficient evidence

The laxative reputation of rhubarb belongs to the anthraquinone-rich root of medicinal Rheum species, not to the garden stalk eaten as food. Human research on eating rhubarb stalks for bowel outcomes does not exist.

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

1 source

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

Kidney and urinary function

Kidney & Urinary Health
Insufficient evidence

The human literature linking rhubarb to the kidney is a harm literature: case reports of oxalate nephropathy after very large intakes, and dietary guidance to restrict it in stone formers. There is no evidence of benefit.

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

1 source

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

Ask about Rhubarb

Ask about Rhubarb

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
Calories21 kcal1%
Protein0.9 g2%
Total fat0.2 g0%
Carbohydrate4.54 g2%
Fibre1.8 g6%
Total sugars1.1 g—
Water93.6 g—
Fats
Saturated fat0.053 g0%
Monounsaturated fat0.039 g—
Polyunsaturated fat0.099 g—
Cholesterol0 mg0%
EPA (omega-3)0 g—
DHA (omega-3)0 g—
DPA (omega-3)0 g—
Linoleic acid (omega-6)0.099 g—
Vitamins
Vitamin A5 µg1%
Vitamin C8 mg9%
Vitamin D0 µg0%
Vitamin E0.27 mg2%
Vitamin K29.3 µg24%
Thiamin (B1)0.02 mg2%
Riboflavin (B2)0.03 mg2%
Niacin (B3)0.3 mg2%
Pantothenic acid (B5)0.085 mg2%
Vitamin B60.024 mg1%
Folate7 µg2%
Vitamin B120 µg0%
Choline6.1 mg1%
Minerals
Calcium86 mg7%
Iron0.22 mg1%
Magnesium12 mg3%
Phosphorus14 mg1%
Potassium288 mg6%
Sodium4 mg0%
Zinc0.1 mg1%
Copper0.021 mg2%
Manganese0.196 mg9%
Selenium1.1 µg2%
Other measured compounds
Beta-carotene61 µg—
Alpha-carotene0 µg—
Lycopene0 µg—
Lutein + zeaxanthin170 µg—
Caffeine0 mg—
Ash0.76 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: Rhubarb, raw (USDA FoodData Central, FDC ID 167758).

% 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.

  • boiledReduces soluble oxalate

    Boiling leaches part of the soluble oxalate into the cooking water, so discarding that water removes some of it. The reduction is partial, and insoluble oxalate is unaffected.

Things to know

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

  • Avoid

    Rhubarb leaves are poisonous

    The leaf blade carries oxalic acid at concentrations that have caused serious poisoning and, historically, deaths. Symptoms include burning of the mouth and throat, vomiting and, in severe cases, kidney injury. Only the stalk is eaten, and the leaves should not be composted where animals graze.

  • Worth knowing

    High oxalate load in the stalks too

    Even the edible stalks are among the highest-oxalate foods measured. People who form calcium oxalate kidney stones are commonly advised to limit rhubarb specifically rather than merely count it towards a total.

  • Worth knowing

    Oxalate binds calcium and iron in the meal

    Oxalate forms insoluble complexes with calcium and iron in the gut, reducing absorption of both from the same meal. That is unlikely to matter occasionally and may matter with habitual large intakes.

  • Too much

    Rhubarb is eaten with a lot of sugar

    The stalk is sour enough that crumbles, compotes and jams carry substantial added sugar. The sugar, rather than the rhubarb, is usually the dominant nutritional feature of the dish.