Though commonly thought to be a vegetable, cucumber is actually a fruit.
It's high in beneficial nutrients, as well as certain plant compounds and antioxidants that may help treat and even prevent some conditions.
Also, cucumbers are low in calories and contain a good amount of water and soluble fiber, making them ideal for promoting hydration and aiding in weight loss.
This article takes a closer look at some of the top health benefits of eating cucumber.
1. It's High in Nutrients
Cucumbers are low in calories but high in many important vitamins and minerals.
One 11-ounce (300-gram) unpeeled, raw cucumber contains the following (1):
• Calories: 45
• Total fat: 0 grams
• Carbs: 11 grams
• Protein: 2 grams
• Fiber: 2 grams
• Vitamin C: 14 percent of the RDI
• Vitamin K: 62 percent of the RDI
• Magnesium: 10 percent of the RDI
• Potassium: 13 percent of the RDI
• Manganese: 12 percent of the RDI
Although, the typical serving size is about one-third of a cucumber, so eating a standard portion would provide about one-third of the nutrients above.
Additionally, cucumbers have a high water content. In fact, cucumbers are made up of about 96 percent water (2).
To maximize their nutrient content, cucumbers should be eaten unpeeled. Peeling them reduces the amount of fiber, as well as certain vitamins and minerals, in a serving (3).
Summary: Cucumbers are low in calories but high in water and several important vitamins and minerals. Eating cucumbers with the peel provides the maximum amount of nutrients.
2. It Contains Antioxidants
Antioxidants are molecules that block oxidation, a chemical reaction that forms highly reactive atoms with unpaired electrons known as free radicals.
The accumulation of these harmful free radicals can lead to several types of chronic illness (4).
In fact, oxidative stress caused by free radicals has been associated with cancer and heart, lung and autoimmune disease (4).
Fruits and vegetables, including cucumbers, are especially rich in beneficial antioxidants that may reduce the risk of these conditions.
One study measured the antioxidant power of cucumber by supplementing 30 older adults with cucumber powder.
At the end of the 30-day study, cucumber powder caused a significant increase in several markers of antioxidant activity and improved antioxidant status (5).
However, it's important to note that the cucumber powder used in this study likely contained a greater dose of antioxidants than you would consume in a typical serving of cucumber.
Another test-tube study investigated the antioxidant properties of cucumbers and found that they contain flavonoids and tannins, which are two compounds that are especially effective at blocking harmful free radicals (6).
Summary: Cucumbers contain antioxidants, including flavonoids and tannins, which prevent the accumulation of harmful free radicals and may reduce the risk of chronic disease.
3. It Promotes Hydration
Water is crucial to your body's function, playing numerous important roles (7).
It is involved in processes like temperature regulation and the transportation of waste products and nutrients (7).
While you meet the majority of your fluid needs by drinking water or other liquids, some people may get as much as 40 percent of their total water intake from food (2).
Fruits and vegetables, in particular, can be a good source of water in your diet.
In one study, hydration status was assessed and diet records were collected for 442 children. They found that increased fruit and vegetable intake was associated with improvements in hydration status (10).
Because cucumbers are composed of about 96 percent water, they are especially effective at promoting hydration and can help you meet your daily fluid needs (2).
Summary: Cucumbers are composed of about 96 percent water, which may increase hydration and help you meet your daily fluid needs.
4. It May Aid in Weight Loss
Cucumbers could potentially help you lose weight in a few different ways.
First of all, they are low in calories.
Each one-cup (104-gram) serving contains just 16 calories, while an entire 11-ounce (300-gram) cucumber contains only 45 calories (1).
This means that you can eat plenty of cucumbers without packing on the extra calories that lead to weight gain.
Cucumbers can add freshness and flavor to salads, sandwiches and side dishes and may also be used as a replacement for higher calorie alternatives.
Furthermore, the high water content of cucumbers could aid in weight loss as well.
One analysis looked at 13 studies including 3,628 people and found that eating foods with high water and low calorie contents was associated with a significant decrease in body weight (11).
Summary: Cucumbers are low in calories, high in water and can be used as a low-calorie topping for many dishes. All of these may aid in weight loss.
5. It Could Help Lower Cholesterol
Research shows that cucumbers contain certain compounds that could reduce blood cholesterol levels.
These compounds include phytosterols or plant sterols, which can be found in many types of fruits and vegetables (12).
Studies show that plant sterols can reduce LDL cholesterol levels by an average of 5–15 percent in most people (13).
One study had participants with and without diabetes supplement with plant sterols. It found that LDL cholesterol levels were reduced by 15 percent in non-diabetic participants and by an impressive 26.8 percent in diabetic participants (14).
Cucumbers also contain pectin, a naturally occurring type of soluble fiber that could decrease blood cholesterol.
An animal study found that administration of pectin extracted from cucumbers caused a significant decrease in both blood cholesterol and triglyceride levels (15).
Summary: Cucumbers contain plant sterols and pectin. Studies show that these two substances could potentially help reduce blood cholesterol levels.
6. It May Lower Blood Sugar
Several animal and test-tube studies have found that cucumbers may help reduce blood sugar levels and prevent some complications of diabetes.
One animal study examined the effects of various plants on blood sugar. Cucumbers were shown to effectively reduce and control blood sugar levels (16).
Another animal study induced diabetes in mice and then supplemented them with cucumber peel extract. Cucumber peel reversed most of the diabetes-associated changes and caused a decrease in blood sugar (17).
In addition, one test-tube study found that cucumbers may be effective at reducing oxidative stress and preventing diabetes-related complications (18).
However, the current evidence is limited to test-tube and animal studies. Further research is needed to determine how cucumbers may affect blood sugar in humans.
Summary: Test-tube and animal studies show that cucumber may help lower blood sugar and prevent diabetes-related complications, although additional research is needed.
7. It Could Promote Regularity
Eating cucumbers may help support regular bowel movements.
Dehydration is a major risk factor for constipation, as it can alter your water balance and make the passage of stool difficult (19).
Cucumbers are high in water and promote hydration. Staying hydrated can improve stool consistency, prevent constipation and help maintain regularity (20).
Moreover, cucumbers contain fiber, which helps regulate bowel movements.
In particular, pectin, the type of soluble fiber found in cucumbers, can help increase bowel movement frequency.
One study had 80 participants supplement with pectin. It found that pectin sped up the movement of the intestinal muscles, all while feeding the beneficial bacteria in the gut that improve digestive health (21).
Summary: Cucumbers contain a good amount of fiber and water, both of which may help prevent constipation and increase regularity.
How to Add Cucumbers to Your Diet
Mild with a distinctly crisp and refreshing flavor, cucumbers are commonly enjoyed fresh or pickled in everything from salads to sandwiches.
Cucumbers are also often eaten raw as a low-calorie snack or can be paired with hummus, olive oil, salt or salad dressing to add a bit more flavor.