Chia seeds (Salvia hispanica) may be a nutrient-rich food, but they can cause side effects, especially if you eat too many. Potential complications of eating chia seeds include digestive issues, choking, medication interactions, allergic reactions, and other health risks.
Two tablespoons of chia seeds contain about 30-40% of your recommended daily amount of fiber. Fiber is essential for healthy digestion. However, too much fiber can cause digestive issues.
If you eat an excessive amount of chia seeds, you may experience digestive issues like:
- Bloating
- Abdominal pain
- Gas
- Constipation
- Diarrhea
Most Americans don’t get enough fiber. If you want to boost your overall intake, increase the amount of fiber you eat per day gradually. This, along with proper hydration, can help avoid digestive discomfort.
Eating large amounts of dry chia seeds can increase your risk of choking. Chia seeds absorb and expand when they touch water. So, if you eat dry chia seeds and then rinse them down with a drink, the seeds can expand in your esophagus (the tube that connects your throat and stomach).
Choking on dry chia seeds may be more likely if you have conditions that cause trouble swallowing (dysphagia) or a narrow or blocked esophagus.
The fiber and phytic acid in chia seeds can affect how your body absorbs minerals like calcium, zinc, and iron. The soluble fiber in chia seeds creates a thick, sticky gel called mucilage inside your digestive system. This gel may make it difficult for your intestines to absorb nutrients.
The phytic acid in chia seeds likes to bind to minerals like calcium, iron, and zinc, which also limits absorption.
Fiber and other nutrients in chia seeds may also affect how your body absorbs some medications by slowing down nutrient absorption. Chia seeds are known to negatively interact with medications like:
- Diabetes medications: Chia seeds can help slow down carbohydrate absorption, which helps regulate blood sugar levels. Mixing chia seeds with diabetes medications may cause significant changes in blood sugar levels.
- Blood pressure medications: The fiber in chia seeds may slow the absorption of blood pressure medications, making them less effective.
- Blood thinners (anticoagulants): The high levels of omega-3 fatty acids in chia seeds may interact with blood thinners enough to prevent clotting.
Chia seeds are a good source of potassium and phosphorus, which are minerals you should limit if you have kidney disease. For reference, a 100-gram serving of chia seeds provides 55% of the Daily Value (DV) for phosphorus and 14% of the DV for potassium.
Damaged kidneys have trouble filtering out potassium and phosphorus from the blood. If you have kidney disease and consume chia seeds, you may increase your risk of potassium and phosphorus buildup.
Eating chia seeds may also increase your risk of calcium oxalate kidney stones, especially if you’ve had kidney stones before. This is because chia seeds are high in oxalate, which binds with calcium in the kidneys to form the stones.
While it sounds contradictory, eating chia seeds with a source of calcium, such as yogurt, can help prevent kidney stones. This is because calcium binds to oxalate in the stomach, preventing it from reaching the kidneys.
Allergic reactions to chia seeds are rare, but possible. Chia seeds, sesame seeds, and hazelnuts contain similar proteins. So, if you have a sesame seed or hazelnut allergy, you may also have an allergic reaction to chia seeds.
Some reported signs and symptoms of an allergic reaction to chia seeds can include:
- Itchy, dry patches of skin
- Itching in the mouth
- Hives
- Facial swelling
- Dizziness
- Shortness of breath
Most people won’t experience negative side effects from eating a standard 2.5-tablespoon serving of chia seeds. However, consuming excessive amounts of chia seeds can lead to excessive fiber intake, which increases your risk of digestive side effects.
Soaking chia seeds in liquids can also help reduce phytic acid that interferes with nutrient absorption and decrease your risk of choking.
