Eating too many chia seeds may cause side effects, such as digestive issues, allergic reactions, or weight gain. In moderation, however, chia seeds can be a nutritious addition to a balanced diet.

Chia seeds are edible seeds that come from a plant belonging to the mint family, called Salvia hispanica. These tiny dark seeds are a nutrient-dense food rich in omega-3 fatty acids and other essential bioactive compounds.

Chia seed consumption may offer health benefits, including lowering blood pressure, reducing inflammation, and improving digestive health.

However, certain individuals may experience side effects if they eat large quantities of chia seeds, including those with diabetes, high blood pressure, and allergies. Too many chia seeds may also lead to digestive issues, and if someone overeats chia seeds, it could lead to weight gain.

This article explores the side effects and risks of eating too many chia seeds, the health benefits of this food, and alternatives.

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Consuming chia seeds may cause some side effects for people with allergies, diabetes, high blood pressure, or digestive issues. We explain their effects on these conditions below.


There are very few reported cases of allergic reactions to chia seeds in scientific literature. In fact, one 2019 study found what researchers believed to be the first chia seed allergy. However, the person involved actually had a medical history of allergies to grass pollen and cat dander.

This individual began consuming chia seeds daily to try and lower their blood cholesterol, and after 3 days, experienced anaphylaxis, a severe allergic reaction, from which they recovered.

There have been some documented cases of hypersensitivity reactions to plants from the same family. These reactions include anaphylaxis, contact dermatitis, and systemic allergic response.

Chia seeds may cause cross-sensitization in people with a sesame allergy. This means that those who already have a sesame allergy may experience an allergic reaction after eating chia seeds.


Chia seeds may lower blood sugar levels because they contain high levels of fiber. The fiber slows sugar absorption in the gut, which helps prevent rapid and significant increases in blood sugar levels.

However, for a person with diabetes, a doctor calculates their insulin dosage precisely to prevent blood sugar spikes and dips. If someone regularly consumes chia seeds, this may cause their blood sugar to decrease enough that they require an insulin dosage adjustment.

High blood pressure

Chia seeds may also lower blood pressure. This might be because these tiny seeds are a rich source of omega-3 fatty acids, which act as blood thinners and decrease blood pressure. However, scientists need to conduct more research into these theories.

Digestive issues

Chia seeds contain plenty of nutrients. However, according to a 2020 study, their tough exterior may make it difficult for the body to break down, release, and digest them. However, this fact is true of most seeds.

In most cases, people should soak chia seeds in water before consuming them or drink water while eating them to aid proper digestion. Ground chia seeds are also a suitable alternative to whole seeds — the body is able to absorb the full nutritional benefits of chia seeds better.

People can also opt for sprouted chia seeds. Allowing chia seeds to germinate optimizes the availability of proteins and increases their calcium content.

Many studies have shown that chia seeds contain vital micronutrient and macronutrient components. The most common macronutrients are carbohydrates, proteins, dietary fiber, and fats.

Chia seeds have a nutritious composition, containing:

  • 15–25% protein
  • 15–35% fat
  • 18–35% dietary fiber
  • 18–31% carbohydrates

They are also suitable sources of antioxidants, vitamins, and other vital minerals.

Chia seeds have high percentages of omega-3 and omega-6 acids. As the body cannot naturally create these nutrients, everyone must consume these essential dietary components.

Some of the health advantages of chia seeds include improved blood sugar and lower blood pressure.

In a 2018 study, researchers fed rats a 10% chia seed diet for 13 months. At the end of the study, they found that the rats who had consumed a 10% chia seed diet had higher bone mineral content and improved structure of liver cells and gut tissue. However, people should note that animal studies do not necessarily apply to humans. More research must continue in this area to better understand the potential effects of chia seeds.

Learn more about the health benefits of chia seeds.

Some alternatives to chia seeds include high fiber foods such as vegetables, legumes, nuts, fruits, and grains. For people interested in boosting their fatty acid consumption, fish is a suitable alternate source of omega-3 fatty acids.

Other nutritious seeds include:

Flaxseed, in particular, contains many of the same benefits as chia seeds, but it is also difficult to digest unless milled. In addition, flaxseed contains lignans, a natural chemical compound. According to the American Heart Association, lignans may potentially protect against prostate cancer and reduce tumor growth in breast cancer.

Chia seeds may cause side effects in people with diabetes, high blood pressure, allergies, or digestive issues. In addition, consuming many of them may lead to weight gain.

However, there are many health benefits to consuming chia seeds, including improved blood sugar, increased blood levels, lower blood pressure, and improved gut health. Chia seeds also contain many essential nutrients the body needs.

Alternatives to chia seeds include other high-fiber foods such as vegetables, legumes, nuts, fruits, and grains. Flaxseed is also a good substitution for chia seeds since it offers many of the same health benefits.