Plum

Food · Fruit · Food, Typed Supps

Prunes aren't just an old home remedy -- real science backs them up for keeping you regular and for helping keep bones strong.

Stage by stage

Chewing & Release (Mouth): Chewing breaks down the plum's skin and flesh, releasing sugars, fiber, and polyphenols like chlorogenic acid for digestion.
Stomach Digestion (Stomach): Most sugars begin breaking down in the stomach, but sorbitol -- especially concentrated in dried plums -- resists digestion and stays largely intact.
Small Intestine Absorption (Small intestine): The small intestine absorbs vitamin C, potassium, and polyphenols into the bloodstream, while fiber and unabsorbed sorbitol move onward to the colon.
Colon & Bone Benefit (Colon & bone tissue): In the colon, sorbitol and fiber draw in water to soften stool and speed transit, while absorbed polyphenols are linked to preserved bone mineral density with months of regular intake.

Timing

Fresh plums can be eaten any time as a snack and dried plums don't require food for absorption, though pairing prunes with a meal can ease GI comfort at higher doses; consistency of daily intake matters more than timing for the digestive and bone benefits shown in trials.

Time to effect

Hours to Months: Softer, more frequent bowel movements can appear within about 24-48 hours of regular dried-plum intake, while bone-density preservation requires consistent daily intake (50g dried plums) for 6-12 months, as shown in randomized controlled trials.

Allergens

None of the fourteen major allergens. Derived from what this food is, not from a product label.

Eating patterns

Fits: Vegan, Vegetarian, Pescatarian, Halal, Kosher, Gluten-free.

In season

July to October in the northern hemisphere, January to April in the southern.

Satiety

174 on the satiety index, where white bread is 100 — high. Modelled from the Holt et al. (1995) measurements.

Environmental footprint

1.1 kg CO2e and 199 litres of freshwater per kg, matched to "Other fruit" in Poore & Nemecek (2018), Science 360.

Cost band

Cheap — roughly £3 per kg, as a band midpoint rather than a price.

Key nutrients

Vitamin C
Vitamin K
Potassium
Sorbitol (concentrated when dried)
Chlorogenic acid (polyphenols)

Nutrition per 100g

Calories: 50
Protein: 0.6g
Carbohydrate: 10.2g
of which sugars: 9g
Fat: 0g
of which saturated: 0g
Fibre: 2g
Sodium: 1mg

Food vs. supplement

Whole plums and prunes combine fiber, sorbitol, and polyphenols in a matrix that outperformed an isolated fiber supplement (psyllium) for relieving constipation in a randomized trial, and no single supplement pill has matched dried plums' documented bone-density effect in controlled trials.

Kitchen tip

For faster digestive relief, choose dried plums (prunes) over fresh, since drying concentrates sorbitol and fiber; for fresh plums, a slight give when gently squeezed signals ripeness and best flavor.

Common myth

"Prunes are just an old wives' tale for constipation -- there's no real science behind it." In reality: Randomized controlled trials show dried plums (prunes) outperform a standard fiber supplement (psyllium) for relieving constipation, and a 12-month randomized controlled trial found that 50g of dried plums daily preserved hip bone mineral density in postmenopausal women -- effects that go well beyond folk-remedy status.