Experts warn about a common mistake some people make when eating chia seeds.
Antioxidant-rich superfoods are known to improve digestion and prevent constipation. However, when consumed without liquids, they can form a "concrete-like mass in your digestive tract" and block it.
Several videos recommending eating and drinking chia seeds have recently gone viral, with many claiming that the seeds can be used to support a diet.
"Chia seeds can absorb 27 times their weight in water, so please don't eat them dry or you'll need to see a gastroenterologist soon," said Dr. Wendy Labret, a gastroenterologist at UCLA Health in California. Videos on TikTok.
In the clip Dr. Lebret shared a photo of a chia seed ball touching a person's esophagus - the passageway that connects the mouth to the stomach.
To avoid such incidents, he advises drinking plenty of water when taking chia seeds and always drinking them first, "otherwise you can end up with a thick, compact mass like concrete."
Dr. Lebret cited a 2014 report in the American Journal of Gastroenterology that found chia seeds affected the esophagus of a 39-year-old man.
An asthmatic patient presented to a hospital in North Carolina complaining of difficulty swallowing.
He told doctors he had swallowed a tablespoon of dried chia seeds 12 hours before seeking medical help - tests revealed the "hydrated chia seed gel" had blocked his esophagus.
The man eventually requested an endoscopy to inject chia seeds into his stomach.
If left untreated, a blockage in the esophagus can cause difficulty swallowing, difficulty eating, breathing problems, and throat irritation.
"Patients should never use dried chia seeds. They can often absorb their weight in water and accumulate in the patient's esophagus, especially if there is a history of swallowing problems," the report's authors said.
But chia seeds are safe when used properly. They should be mixed with enough liquid before eating to expand.