While not listed as a top 8 food allergen, chia seeds can cause allergies among some people. Some people may experience symptoms like gastrointestinal distress, itching, hives and swelling after eating, and should seek medical care immediately. While chia seeds are mostly safe, there was a report of a GI blockage reported after a man consumed dry chia seeds. It's best to consume in liquids or mixed in with other foods.