Is the white part of watermelon rind good for you?

The white part of a watermelon rind is the innermost layer just below the green exterior. Many people discard watermelon rinds, but they are actually edible and contain some surprising health benefits.

Watermelon rinds are full of nutrients including vitamins, minerals, antioxidants and amino acids. Eating watermelon rind provides dietary fiber, vitamin C, vitamin B6, potassium, magnesium and more. Research suggests watermelon rind may also have anti-inflammatory, antioxidant, anticancer and heart health benefits.

Here is an overview of the main nutrients found in watermelon rinds and the potential health benefits:

Nutrients in Watermelon Rind

  • Dietary fiber – Improves digestion and heart health
  • Vitamin C – Immune booster with antioxidant effects
  • Vitamin B6 – Supports metabolism and brain function
  • Potassium – Important for blood pressure, nerves and muscles
  • Magnesium – Bone health, migraine relief and mood support
  • Lycopene – A potent antioxidant that may protect against cancer
  • Citrulline – An amino acid that enhances exercise performance
  • Cucurbitacin E – Anti-inflammatory and antioxidant compound

Potential Health Benefits of Watermelon Rind

  • Improves digestive health
  • Boosts the immune system
  • Supports heart health
  • Reduces inflammation
  • Protects against certain cancers
  • Enhances athletic performance and recovery
  • Lowers blood pressure
  • Promotes brain function

Nutritional Profile of Watermelon Rind

Watermelon rind is low in calories but packed with important vitamins, minerals and antioxidants. Here is the nutritional breakdown for 100 grams of watermelon rind (3):

Watermelon Rind Nutrition Facts

Nutrient Amount % Daily Value
Calories 30 2%
Protein 0.9 g 2%
Carbs 7.5 g 3%
Fiber 2 g 8%
Sugar 3.4 g
Fat 0.2 g 0%
Vitamin C 13.4 mg 15%
Vitamin A 569 IU 11%
Vitamin B6 0.05 mg 3%
Potassium 112 mg 3%
Magnesium 10 mg 3%
Calcium 10 mg 1%

As you can see, watermelon rind provides a variety of vitamins and minerals, particularly vitamin C, vitamin B6, potassium and magnesium. It is also a source of dietary fiber.

Next, let’s explore the evidence behind some of the major health benefits of watermelon rind.

1. Improves Digestive Health

One of the top benefits of watermelon rind is improved digestion and regularity. The dietary fiber in watermelon rind helps promote healthy bowel movements and prevent constipation.

Fiber adds bulk to stool and draws water into the intestines, allowing waste to pass more easily. Soluble fiber forms a gel-like texture, while insoluble fiber doesn’t dissolve in water. Both types of fiber help prevent constipation by improving stool consistency (1).

A 100 gram serving of watermelon rind contains 2 grams of dietary fiber, meeting 8% of the daily fiber needs for adults. Combining the rind with the red flesh increases the fiber content even more.

The laxative effect of watermelon rind fiber allows people to avoid medications like laxatives. A study in rats found the rind fiber was as effective as a common laxative drug for treating constipation (2).

Fiber also feeds the good bacteria in the gut microbiome. The healthy bacteria ferment fiber into beneficial short-chain fatty acids that support gut health and reduce inflammation (3).

Key Point

Watermelon rind is an excellent natural source of fiber for improving digestive regularity, gut microbiome health and preventing constipation.

2. Boosts the Immune System

Watermelon rind is one of the best dietary sources of vitamin C. One serving contains 13.4 mg of vitamin C, meeting 15% of the daily value (4).

Vitamin C is arguably the most important nutrient for immune function. It stimulates the production of white blood cells, antibodies and other components of the immune system. This antioxidant also helps remove harmful free radicals that can damage cells.

Studies consistently link higher vitamin C intake to reduced severity and duration of respiratory infections like the common cold (5). People with low vitamin C levels are at greater risk of infections and lung-related complications.

Consuming watermelon rind and other vitamin C foods can strengthen the immune system and prevent sickness, especially during times of stress or change in seasons. The antioxidant activity of vitamin C and lycopene in watermelon rind also helps fight inflammation.

Key Point

Watermelon rind provides vitamin C for antioxidant effects and boosting immune defenses against pathogens and lung infections.

3. Supports Heart Health

Heart disease is the leading cause of death worldwide. Lifestyle factors like diet play a major role in heart health. Several nutrients in watermelon rind help reduce risk factors for heart disease.

The fiber content helps lower cholesterol levels. Soluble fiber binds to cholesterol in the intestines and removes it from the body before it can be absorbed. Studies show that getting more soluble fiber from fruits, vegetables and whole grains is associated with lower LDL (“bad”) cholesterol (6).

Watermelon rind also provides potassium, an essential mineral for heart health. Potassium allows the cardiovascular system to function properly. It helps balance electrolytes, regulate heartbeat regularity and lower blood pressure (7).

The citrulline in watermelon rind may also support heart health by dilating blood vessels. Citrulline is converted to arginine, an amino acid that enhances nitric oxide levels and relaxes arteries (8).

According to a study in rats, the oil extracted from watermelon rinds protected against cholesterol-induced atherosclerosis by lowering LDL and raising HDL (“good”) cholesterol (9).

Key Point

Nutrients in watermelon rind like fiber, potassium and citrulline promote heart health by improving cholesterol levels and blood pressure.

4. Reduces Inflammation

Chronic inflammation is at the root of most diseases, including heart disease, diabetes, cancer, arthritis and autoimmune disorders. Lifestyle factors like diet, exercise, sleep and stress management all affect inflammation levels in the body.

Watermelon rind contains several anti-inflammatory antioxidants. Vitamin C lowers inflammatory markers like C-reactive protein (CRP) and tumor necrosis factor alpha (TNF-a) (10). The carotenoid antioxidant lycopene also reduces inflammation.

The compound cucurbitacin E is responsible for the bitter taste of watermelon rind. However, research shows cucurbitacin E has potent anti-inflammatory and antioxidant effects in the body (11).

For people with inflammatory conditions, consuming watermelon rind provides natural compounds that inhibit the inflammatory response. Using the rinds to make juice, smoothies or pickles is a delicious way to fight inflammation.

Key Point

Antioxidants in watermelon rind such as vitamin C, lycopene and cucurbitacin E reduce inflammation when consumed regularly.

5. Protects Against Certain Cancers

Research suggests that nutrients in watermelon rind may help prevent the growth and spread of certain types of cancers.

Lycopene is a bright red carotenoid pigment in watermelon flesh and rind. Studies link higher lycopene intake to a lower risk for prostate, lung and stomach cancers (12).

Lycopene fights cancer formation by neutralizing free radicals before they can damage cells. It also enhances cell-to-cell communication to suppress tumor growth (13).

The cucurbitacin compounds found in cucurbit plant species like watermelon have exhibited anticancer effects in cell studies. Cucurbitacin E prevented the proliferation of human lung, colon cancer and leukemia cells (14, 15).

While more human research is needed, preliminary evidence indicates watermelon rind may help protect against certain cancers through its antioxidant and anti-inflammatory activities.

Key Point

The lycopene and cucurbitacin E in watermelon rind exhibit antioxidant, anti-inflammatory and anticancer effects that may inhibit tumor growth.

6. Enhances Athletic Performance and Recovery

Watermelon rind contains citrulline, a non-essential amino acid that is gaining popularity as a sports supplement. Citrulline is converted to arginine in the kidneys to enhance nitric oxide levels and increase blood flow (16).

Studies show that citrulline from watermelon improves exercise performance by reducing fatigue. Cyclists pedaled faster and longer after taking citrulline malate supplements from watermelon rind (17).

Citrulline also helps relieve muscle soreness after exercise. In one study, people reported less muscle soreness 24-48 hours after a leg workout when supplemented with citrulline (18).

By boosting nitric oxide, citrulline allows athletes to train harder and recover faster. Enjoying watermelon rind as a snack or in a smoothie is a natural and refreshing way for athletes to enhance performance.

Key Point

The citrulline in watermelon rind enhances exercise endurance and helps relieve post-workout muscle soreness.

7. Lowers Blood Pressure

About one third of adults have high blood pressure, a major contributor to heart disease and stroke (19). Lifestyle modifications like losing weight, exercising, avoiding smoking and improving the diet are effective ways to lower blood pressure.

Several nutrients in watermelon rind help reduce blood pressure levels. The fiber, potassium, lycopene and citrulline all have beneficial effects on hypertension.

Fiber reduces blood pressure by binding to sodium and removing it through the urine. Potassium counters the effects of sodium by relaxing blood vessel walls (20).

Lycopene enhances the effects of blood pressure medications by inhibiting HMG-CoA reductase enzyme. And citrulline from the rind is converted to arginine to dilate arteries and lower pressure (21).

Key Point

The fiber, antioxidants, minerals and amino acids in watermelon rind reduce hypertension, a major risk factor for heart disease and stroke.

8. Promotes Brain Function

Some B vitamins in watermelon rind support brain health and prevent cognitive decline. Vitamin B6 aids in the synthesis of neurotransmitters for mood regulation and healthy brain aging (22).

Research also shows the lycopene in watermelon protects against learning and memory issues. Supplementing rats with lycopene helped restore memory impairment and reduced oxidative stress in the brain (23).

The citrulline in watermelon rind enhances circulation by converting to arginine and boosting nitric oxide. Improved blood flow ensures the brain gets plenty of oxygen and nutrients for optimal cognition.

Key Point

Nutrients like B vitamins and lycopene in watermelon rind promote better brain function, memory and mood.

9. Easy Ways to Eat Watermelon Rind

Here are some simple ways to incorporate watermelon rind into your diet:

1. Pickles

Pickle watermelon rind for a tangy, crunchy snack or condiment. Use a basic brine of vinegar, water, sugar and spices.

2. Juice

Add watermelon rind to your juicer along with the red flesh and other fruits and veggies.

3. Stir fry

Dice rind and add it to stir fries for a crispy texture.

4. Soup

Blend or boil watermelon rind into hearty soups.

5. Smoothies

Throw watermelon rind into smoothies to ramp up fiber, nutrients and texture.

6. Salsa

Chop rind and mix with tomatoes, onion and lime juice for a fresh salsa.

7. Bake into breads

Add some diced rind to your favorite banana, zucchini or other vegetable bread recipe.

8. Infused water

Infuse sliced watermelon rind into a pitcher of water for a refreshing beverage.

9. Salad

Toss cubed watermelon rind into leafy green or grain salads.

Conclusion

Watermelon rind packs a concentrated dose of nutrients despite its light, crunchy texture. The fiber, vitamins, minerals and antioxidants in the rind provide digestive health, immune, heart health and anti-inflammatory benefits.

Compounds like lycopene and cucurbitacin E may also protect against certain cancers. Citrulline in the rind enhances exercise recovery and endurance. And B vitamins support brain function.

While many discard the rind, consuming watermelon whole is an easy way to maximize its nutritional value. The rind’s pleasantly mild flavor lends itself well to pickling, juicing, smoothies and a variety of cooked dishes.

So next time you enjoy watermelon, consider eating the nutrient-dense rind too and reap the many health perks.

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