Quick answers
Black watermelon seeds contain nutrients like protein, magnesium, iron, zinc and fiber. They are a good source of antioxidants and may provide some health benefits like reduced inflammation, lower blood pressure and improved heart health. However, they also contain phytic acid which can reduce mineral absorption. In moderation, black watermelon seeds can be a healthy snack or additive but should not completely replace other nutritious foods.
What are black watermelon seeds?
Watermelon seeds come from the watermelon fruit (Citrullus lanatus) which is part of the cucurbit family along with cucumbers and squash. Watermelon seeds can be black, brown, white or yellow in color though the black seeds are most common.
Watermelon seeds consist of a white inner kernel enclosed in a black or brown outer shell. The seed coat protects the inner seed and contains fiber, protein, fat, minerals and polyphenols like flavonoids.
While the red flesh of the watermelon is consumed, the seeds are typically discarded. However, the seeds can be roasted, dried and eaten as a snack much like pumpkin seeds.
Watermelon seed nutrition facts
Here is the nutrition information for 1 ounce (28g) serving of dried, roasted black watermelon seeds (1):
- Calories: 161
- Protein: 8g (16% DV)
- Fat: 14g (22% DV)
- Carbs: 5g (2% DV)
- Fiber: 2g (7% DV)
- Magnesium: 105mg (26% DV)
- Phosphorus: 309mg (31% DV)
- Iron: 2mg (11% DV)
- Zinc: 2mg (18% DV)
- Copper: 0.3mg (16% DV)
- Manganese: 0.5mg (24% DV)
As you can see, watermelon seeds are high in fat and protein compared to the watermelon flesh. They also contain substantial amounts of magnesium, phosphorus, iron, zinc and copper.
Additionally, they provide beneficial plant compounds like lycopene, flavonoids, stearic acid and arginine (2).
Potential health benefits
Due to their impressive nutritional profile, black watermelon seeds are linked to several health benefits.
High in antioxidants
Antioxidants are compounds that prevent cell damage from free radicals and reactive molecules known as oxidative stress. Oxidative stress has been linked to chronic diseases like cancer, diabetes and heart disease (3).
Black watermelon seeds are rich in antioxidants including lycopene, lutein, arginine and flavonoids. In fact, they contain higher levels of lycopene than the watermelon flesh does (4).
Lycopene in particular has been studied extensively for its antioxidant capacity. According to research, lycopene demonstrates free radical scavenging activity and may protect cells against oxidative damage (5).
May reduce inflammation
Inflammation is a normal immune response, but chronic inflammation can contribute to chronic disease. Studies show that the antioxidants in black watermelon seeds may help fight inflammation.
In one study, rats fed defatted watermelon seed flour had decreased levels of inflammatory markers compared to a control group (6).
Another study had similar findings, demonstrating that mice given watermelon seed extract had reduced inflammation. The anti-inflammatory effects were attributed to the antioxidants in the seeds (7).
Thanks to their anti-inflammatory properties, regularly eating watermelon seeds may aid chronic inflammatory conditions like arthritis, asthma and inflammatory bowel disease (IBD).
May improve heart health
Heart disease is the leading cause of death worldwide. Lifestyle factors like diet can strongly influence heart disease risk.
Black watermelon seeds have been linked to improved heart health due to their high content of antioxidants, magnesium, amino acids and unsaturated fatty acids. These nutrients are thought to lower blood pressure, improve blood flow and decrease cholesterol and triglycerides (8).
A study in obese mice found that those fed watermelon seed extract for four weeks had a significant reduction in total cholesterol, triglycerides and LDL cholesterol compared to a control group (9).
Another study showed that giving mice suffering from induced myocardial infarction watermelon seed extract helped reduce oxidative stress, improve heart function and decrease mortality rate (10).
Though more research in humans is needed, the current evidence suggests black watermelon seeds may promote heart health when consumed as part of a healthy diet.
May lower blood pressure
High blood pressure affects an estimated 1 billion people worldwide and is a major risk factor for stroke, heart attack, kidney failure and cognitive decline (11).
Studies indicate that the minerals, antioxidants and amino acids in black watermelon seeds may help reduce blood pressure levels.
A study in rats with induced hypertension found that those fed watermelon seed extract had significantly reduced blood pressure compared to a control group (12).
The blood-pressure-lowering effect is likely due to the high concentration of L-arginine in the seeds. L-arginine is an amino acid that enhances vasodilation and blood flow (13).
Additionally, the magnesium in watermelon seeds helps relax blood vessels to optimize blood flow and reduce pressure (14).
While the current research is limited to animal studies, it suggests black watermelon seeds may aid lower blood pressure when combined with a well-rounded diet and healthy lifestyle.
Downsides and precautions
While research shows black watermelon seeds may provide some impressive health benefits, there are some downsides to consider.
High in calories and fat
A 1-ounce (28-gram) serving of dried watermelon seeds packs over 160 calories and 14 grams of fat. This makes them much higher in calories and fat than the watermelon flesh which contains only 86 calories and 2 grams of fat per cup (152 grams) (15).
About 61% of the fat in watermelon seeds comes from polyunsaturated and monounsaturated fatty acids like oleic acid and linoleic acid (16).
These unsaturated fats are considered healthy fats and have been associated with improved insulin sensitivity and cholesterol levels in some studies (17).
However, those looking to lose weight will still need to moderate portions to account for their high calorie and fat contents.
Contains phytic acid
Phytic acid, or phytate, is a compound found in plant seeds. It can reduce absorption of minerals like iron, zinc and calcium from the digestive tract (18).
In the past, phytic acid got a bad reputation for being an antinutrient. However, it also provides some health benefits, functioning as an antioxidant in the body.
Enjoying black watermelon seeds in moderation poses little risk for healthy adults. Those at risk of mineral deficiencies like iron deficiency may want to limit intake and consume them alongside other nutritious foods to improve absorption.
Potential choking hazard
Due to their small size and shape, black watermelon seeds may pose a choking risk, especially in children.
It’s best to completely avoid whole watermelon seeds for children under the age of four. For older kids and adults, take care to chew seeds properly before swallowing to prevent choking (19).
Additionally, inspect seeds for broken shells or damage before eating. Broken shells can increase the risk of choking as they may lodge in the throat.
How to eat black watermelon seeds
Black watermelon seeds can be consumed either dried or fresh. Here are some ways to enjoy them:
Roasted and dried
This involves drying fresh watermelon seeds and then roasting them for a crispy texture. Once dried, the seeds last for up to a year when stored properly in an airtight container.
Look for roasted watermelon seeds at natural grocery stores or online retailers. They make for a tasty and portable snack.
Sprouted
Sprouting black watermelon seeds increases the bioavailability of nutrients and makes them easier to digest (20).
To sprout them, simply soak the seeds overnight, rinse and then allow to sprout for 1–2 days until the seed coat splits.
Add the sprouted seeds to salads, smoothies or sandwiches.
Ground into flour
Grinding up roasted watermelon seeds creates a nutritious gluten-free flour. Use the flour for baking or add it to smoothies.
Store watermelon seed flour in the refrigerator or freezer to maximize freshness.
As a snack
Fresh black watermelon seeds can be rinsed, dried and eaten as a snack raw. Their mild, nutty taste makes them a healthy alternative to chips or roasted nuts.
Children over the age of four can also enjoy fresh watermelon seeds in moderation while supervised.
Added to granola or trail mixes
Toss dried black watermelon seeds into homemade granola or trail mixes for some added nutrition and crunch.
Blended into smoothies
For a dose of plant protein, fiber and magnesium, add a few tablespoons of dried or fresh watermelon seeds to your favorite smoothie.
Used in baked goods
Mix roasted watermelon seed flour or dry seeds into cookies, bars or breads.
Takeaway
Here is a summary of the article:
- Black watermelon seeds contain nutrients like protein, magnesium and iron and provide antioxidants like lycopene.
- Research shows they may offer benefits like reduced inflammation, lower blood pressure and improved heart health.
- Potential downsides include their high calorie and fat content, phytic acid reducing mineral absorption and choking risk in kids.
- You can enjoy black watermelon seeds roasted and dried, sprouted, ground into flour or added to foods like smoothies and granola.
- In moderation, watermelon seeds can be a nutritious snack but should not replace other healthy foods in the diet.
Conclusion
Black watermelon seeds are highly nutritious and provide protein, healthy fats and minerals, as well as antioxidants like lycopene. Research indicates they may help lower blood pressure, reduce inflammation and promote heart health.
However, they are high in calories and fat and also contain phytic acid. To avoid potential mineral deficiencies, enjoy them in moderation along with a varied diet.
Roasted in oil and lightly salted, black watermelon seeds make for a tasty, portable snack. They can also be sprouted, ground into nutritious gluten-free flour or added to foods like smoothies and granola.
While certain people should avoid watermelon seeds, such as children under four due to choking hazards, black watermelon seeds can be a healthy dietary addition for most when consumed responsibly.
