Plums and prunes are closely related fruits that provide many health benefits. Both are highly nutritious, being rich in fiber, vitamins, minerals and antioxidants. However, they are perhaps best known for their laxative effect, which helps relieve constipation.
This article reviews the evidence on whether plums have the same laxative effect as prunes.
What Are Plums and Prunes?
Plums and prunes belong to the same species of fruit trees called Prunus domestica. They are classified as stone fruits or drupes, meaning they have a hard stone or pit surrounded by edible flesh.
Plums can be divided into two general types:
- Japanese plums: Typically round and red, pink or yellow in color.
- European plums: Usually blue or purple with a tear-drop shape.
Prunes are actually dried plums. They are produced by dehydrating ripe plums to remove the water content. A prune contains about 85% less water than a fresh plum.
That said, most dried prunes are made from cultivars grown specifically for drying. These plums tend to be very sweet with higher solids levels than the varieties sold fresh in markets.
Nutrition Facts
Plums and prunes are highly nutritious, being packed with fiber, vitamins, minerals and beneficial plant compounds.
A 100-gram serving provides the following nutrients:
| Nutrient | Plums | Prunes |
|---|---|---|
| Calories | 46 | 240 |
| Fat | 0.3 g | 0.38 g |
| Protein | 0.7 g | 2.18 g |
| Carbs | 11.4 g | 63.88 g |
| Fiber | 0.7 g | 7 g |
| Vitamin A | 6% DV | 4% DV |
| Vitamin C | 10% DV | 1% DV |
| Vitamin K | 5% DV | 31% DV |
| Potassium | 2% DV | 12% DV |
| Copper | 6% DV | 10% DV |
DV = Daily Value. Source: USDA FoodData Central
Prunes are higher in calories, carbs, fiber and potassium compared to fresh plums. Plums contain more vitamin C.
Fiber Content
The key nutritional difference between plums and prunes is their fiber content.
A plum contains only 0.5–1 gram of fiber per 100 grams, whereas prunes contain 7 grams (). That’s 7–14 times as much fiber as you get from plums.
Additionally, prunes contain soluble fiber, which forms a gel-like substance in your gut. This slows digestion, promotes fullness and helps maintain regular bowel movements.
Sugar Content
Since prunes are dried plums, they contain much higher concentrations of sugars:
| Sugar | Plums | Prunes |
|---|---|---|
| Glucose | 2.4 g | 31.6 g |
| Fructose | 2.4 g | 31.5 g |
| Sucrose | 0.9 g | 0.7 g |
| Total | 5.7 g | 63.8 g |
Per 100 grams, prunes contain over 11 times the total sugars found in plums. The drying process concentrates the sugars into a small, dense, convenient package.
Sorbitol
Prunes are particularly high in the sugar alcohol sorbitol. It’s a naturally occurring sugar found in stone fruits.
Many studies have shown that sorbitol acts as a natural laxative by drawing water into the large intestine, which helps stimulate bowel movements.
For this reason, sorbitol is commonly used in sugar-free gums and candies to prevent constipation. It’s also added to some medications for the same reason.
Each prune contains about 0.63 grams of sorbitol. Raisins, apricots and apples also contain sorbitol, but at much lower concentrations.
Do Plums Have Laxative Effects?
Research indicates prunes are more effective than plums for relieving constipation.
In one study, participants ate about half a pound (200 grams) of plums or prunes every day for three months. The prune group experienced significant improvements in constipation frequency and stool consistency.
Additionally, in a study comparing apples, pears, prunes, chokeberries and kiwi fruit, prunes ranked highest for improving markers of gut function.
Another trial in 40 constipated elderly people found that eating 8–12 prunes per day significantly improved stool frequency and consistency, compared to treatments with psyllium fiber or wheat bran.
There are several reasons why plums may be less effective than prunes:
- Plums contain significantly less fiber and sorbitol, which are important for regularity.
- The skin and flesh of plums contain sugars that are readily absorbed in the small intestine, providing fewer calories to feed the good bacteria in your colon.
- Plums contain fructose, which may cause mild laxative effects in some people. However, only a small amount of fructose is available once plums are digested in the gut.
- Plums have not been studied specifically for their effects on constipation, while prunes are well known for this purpose.
For these reasons, plums are unlikely to have the same strength of effect as prunes when it comes to improving constipation.
Other Potential Benefits
Aside from improving bowel function, plums and prunes offer a few additional health benefits.
Bone Health
Prunes contain some nutrients that benefit bone health. They’re rich in vitamins K and A, plus the mineral boron. All of these contribute to building and maintaining strong bones.
Additionally, some researchers have suggested prunes may enhance the body’s ability to absorb calcium, which is essential for bone health.
One study in postmenopausal women found that eating 5–6 prunes daily for a year led to significantly higher bone mineral density in the forearm and spine compared to a group who ate only 1 prune daily.
Another trial concluded that prunes are more effective at preventing bone loss in postmenopausal women than some standard osteoporosis drugs.
Blood Sugar Control
Plums contain polyphenol antioxidants that may help control blood sugar levels. Diets high in these antioxidants may help prevent diabetes by reducing insulin resistance and inflammation.
One human study showed significantly lower blood sugar spikes in a group that consumed plum juice with sugar, compared to a control group that drank only sugar water.
Additionally, some animal research indicates consuming plum extracts may lower blood sugar levels comparable to diabetes medication.
However, more studies are needed to confirm these effects in humans.
Skin Health
Research indicates that stone fruits like plums and prunes contain compounds that nourish your skin from the inside out.
When digested, these compounds form molecules called polyphenol metabolites. These metabolites become part of your skin cells and help protect against sun damage.
Getting enough vitamin C also promotes skin health and appearance. Plums happen to be richer in vitamin C than prunes.
Adverse Effects
When consumed in moderation, prunes and plums do not have many known adverse health effects.
That said, they contain high amounts of fermentable carbs known as FODMAPs. These include sorbitol, fructose and fructans.
In some people, diets high in FODMAPs can cause unpleasant digestive symptoms like gas, bloating and abdominal pain. Those with irritable bowel syndrome (IBS) may need to limit high FODMAP foods.
Additionally, prunes are relatively high in oxalates, which some individuals need to restrict for health reasons. People prone to kidney stones may want to limit their prune intake.
In general, if you experience any negative effects after eating prunes or plums, try reducing your intake.
The Bottom Line
Both plums and prunes are nutritious, but prunes appear to be much more effective for relieving constipation.
Compared to fresh plums, prunes contain higher amounts of fiber, sorbitol andphenolic compounds, all of which have natural laxative effects.
Prunes also hold up better during digestion, allowing their nutrients to reach your colon where they can improve stool consistency and frequency.
While plums offer some constipation relief, they tend to be less reliable than prunes. Prunes are widely regarded as a safe, gentle and effective remedy for constipation.
If you’re looking for relief from constipation, prunes are likely the better choice over plums.
Conclusion
In summary, both plums and prunes are very nutritious fruits that offer a range of health benefits. However, research shows prunes are more effective for relieving constipation. They contain higher amounts of fiber, sorbitol and beneficial plant compounds that support regular bowel movements.
For most people, prunes are a safe and natural way to find constipation relief without the side effects of laxatives. If you struggle with regularity, trying some prunes may be worthwhile.
