Myths abound when it comes to watermelon seeds. Are white seeds really safer to eat than black seeds? Is it best to stick to seedless watermelon? And while you probably know that consuming black seeds isn’t going to cause a watermelon to grow in your stomach—are there legitimate health reasons to avoid them?
Here’s the truth: If you swallow some watermelon seeds, you should be absolutely fine. In fact, you may reap some health benefits.
“The white ‘seeds’ in a seedless watermelon are actually empty seed coats where a seed did not fully mature,” Toby Amidor, RD, author of Up Your Veggies: Flexitarian Recipes for the Whole Family, told Verywell, adding that they are safe to eat. “The black seeds in a regular watermelon are mature, fertile seeds that would sprout into a watermelon plant if you planted a few in the soil. They are safe to eat and will pass through your body, as they are insoluble fiber.”
Other sources of soluble fiber include black beans, Brussels sprouts, and avocados.
For most people, it’s perfectly safe and healthy to swallow any type of watermelon seed. Watermelon seeds are natural sources of many nutrients, including iron, folate, and niacin.
“While they’re not too pleasant to munch on by themselves, watermelon seeds actually can provide a great nutritional boost,” Kacie Barnes, MCN, RDN, a Dallas-based registered dietitian, told Verywell.
Some people make watermelon seed butter, flour, or simply roast the seeds in order to include them in their diet, she said.
Amidor cautions that consuming watermelon seeds may lead to constipation or gastrointestinal discomfort for those with a sensitive digestive system.
Too many seeds may give your body a major fiber boost, which can lead to digestive challenges if your body isn’t used to them. But no data exists suggesting an upper safe limit to watermelon seed consumption.
Which Seeds and Pits Are Not Safe to Eat?
It may be a relief to know that you don’t have to pick out every watermelon seed. But this news shouldn’t be interpreted as a pass to eat every seed and pit in your fruits and veggies.
Amidor explains that many seeds and pits that are safe to eat, including:
But there are others that can cause harm when consumed in excess.
Cherry Pits
Cherry pits contain prussic acid, also known as cyanide, which is poisonous. If you swallow one or two pits whole, they will pass through your digestive system and are unlikely to cause any harm. However, you should avoid crushing or crunching on these pits. Broken-down cherry pits expose your body to prussic acid more easily. (If you watched Ozark, you know exactly what can happen. Poor Jacob Snell.)
Apple Seeds
Apple seeds also contain cyanide. If you do swallow some apple seeds, know that their natural protective coating keeps them from entering your digestive system. But consuming too many chewed or crushed apple seeds may be a cause for concern.
Apricot Seeds
Apricot seeds, found inside of the pit, also contain cyanide. They can cause a stomach ache and illness when consumed, and are very toxic for children. Some evidence suggests that cyanide poisoning associated with ingestion of apricot seeds is so poisonous in children that many who ingest it require intensive care.
Red Kidney Beans
While not technically a seed or a pit, red kidney beans are worth mentioning because they contain a high level of a lectin called phytohemagglutinin, which has toxic effects on humans when consumed. The unit of measure for toxins is called the hemagglutinating unit (hau). Raw kidney beans have between 20,000 to 70,000 hau, while fully-cooked beans contain 200 to 400 hau.
White kidney beans have one-third the amount of the toxin compared to red kidney beans.
According to Amidor, as few as four or five raw or soaked red kidney beans can trigger toxicity within one to three hours. Symptoms include nausea, vomiting, diarrhea, and abdominal pain.
Eating fruits, veggies, and beans can help support an overall balanced and healthy diet, and eating more of these foods is typically beneficial. But, there are some seeds, pits, and raw foods that are surprisingly risky to consume. From apple seeds to cherry pits, making sure to avoid crushing and swallowing certain seeds, pits, and raw items is a wise step to help keep your body safe.
Thankfully for watermelon lovers, those tiny seeds fall into this “safe” category for most people.