The seeds of these watermelons can cause intestinal obstruction if ingested in large quantities.

A watermelon cut in half.

One of the most common terrors among children is swallowing a watermelon nugget and having a tree grow inside them, something obviously unlikely. But this fear of swallowing the seeds of this red fruit has a real basis: taking seeds of watermelon or other similar seeds in large quantities, can cause a bowel obstruction.

The reason is the composition of the seed itself, which has a hard cellulose shell, and the human digestive system, which does not have the necessary enzymes to digest this material. “In principle, if they are not ingested in large quantities, its nutrients will not be absorbed and will be expelled from the body as is, without generating any kind of problem ”, explains to EL ESPAÑOL Victoria Díaz, dietician-nutritionist.

However, due to its small size and that armor that protects them, lseeds can pass through the pylorus and ileocecal valve, on the way to the large intestine, and gradually accumulate in the colon. In this way, it is enough that the intake of these seeds is continued, although not in large quantities, to cause a real problem in the digestive system.

Relationship with appendicitis

Although to a much lesser extent, eating seeds that have not been previously ground can also cause appendicitis. This is revealed by an analysis carried out by several researchers from the Bozyaka Research and Training Hospital, Turkey, which concluded that only in 0.05% of cases are they related to the intake of seeds of fruits. “The rate of acute appendicitis caused by plants is minimal, but avoiding eating whole fruit seeds can help prevent this dangerous inflammation,” the scientists conclude in the study.

The usual thing is that 95% of the substances that are ingested, pass through the digestive system without causing complications. But that remaining 5% is made up of substances with different characteristics that make it easy for them to accumulate in the last part of the large intestine, the cecum, thus obstructing the connection with the appendix, causing its inflammation.

They can cause intestinal obstruction

Studies such as the one carried out by the department of surgery at the Galilee Medical Center, in Israel, revealed that indeed the intake of watermelon, prickly pear or sunflower seeds it can cause complications that land the person in the hospital. The study, carried out over 18 years, from 1996 to 2005, collected all the cases of fecal impaction or fecaloma treated at the center.

In 55% of these cases, the motive was a phytobezoar, that is, a hard mass of undigested plant materials, which accumulate in the stomach and small intestine. In most cases, the origin was in the intake of prickly pear and watermelon seeds. In addition, the treatment of these patients required hospitalization and, unlike other types of obstructions, the removal of these accumulations required general anesthesia.

A group of surgeons from various hospitals in Athens, Greece, conducted a similar investigation, the data of which was published in 2019. In particular, they decided to review the documented cases of this type of obstruction, from 1980 to 2018. They found that 72% of patients, both children and adults, came from Mediterranean and Middle Eastern countries, since this fruit is part of the Mediterranean diet, and that most had been produced by watermelon seeds.

Symptoms and risk factors

The most common symptoms among patients suffering from an intestinal obstruction, after eating watermelon seeds, are: constipation, abdominal and rectal pain, accompanied by tenesmos or stools stained with blood. As for the recognized risk factors are: previous gastric surgery, neuropsychiatric disease, endocrinopathies that alter gastrointestinal motility and poor chewing. In the case of the formation of bezoars in the intestine, not linked to the ingestion of seeds, there are gastrointestinal strictures, diabetes and neuropsychiatric disease.

Benefits if eaten ground

Despite all the inconveniences that watermelon seeds can bring to the digestive system, toasting and grinding them is a very good way to take advantage of all the nutrients that they can contribute to the body. The troublesome peel, ground, can be a rich supply of fiberWhile the seed inside contains protein, minerals and healthy fats.

Specifically, for every 100 grams, they contain 557 calories, zero sugars, 99 milligrams of sodium and 28.33 of protein. In addition to vitamins such as B3, niacin, essential for the metabolism of carbohydrates and fats, which also helps reduce harmful cholesterol, and B9, that is, folic acid, necessary for the production of red blood cells and the synthesis of DN.

They are also rich in phosphorus, vital for bones; magnesium, which regulates the immune system and muscle function; potassium, a type of electrolyte related to nerve function and muscle contraction; zinc, base for the immune system; and manganese, related to the proper functioning of the thyroid gland, the regulation of blood sugar levels and the absorption of calcium.

In this way, by grinding the watermelon seeds, you can enjoy all the benefits they can bring, thus avoiding any type of risk such as intestinal obstructions and appendicitis.