Chia seeds, which are derived from the Salvia hispanica plant, are super nutritious and fun to eat.
They’re used in a variety of recipes, including puddings, pancakes and parfaits.
Chia seeds have the unique ability to absorb liquid and take on a gelatinous consistency. For this reason, they’re often used as a thickening agent and can even be used as a vegan substitute for eggs in some baked goods (1).
In addition to their gelling and thickening properties, chia seeds are well known for their impressive array of nutrients and potential health benefits.
However, while chia seeds can be a nutritious dietary addition for most, eating too may cause some side effects.
This article examines the side effects of eating too many chia seeds.
One major reason people eat chia seeds is because they’re highly nutritious. They provide a good amount of fiber, protein, healthy fats and micronutrients.
In fact, just 1 ounce (28 grams) of chia seeds provides up to 42% of your daily recommended fiber, in addition to hearty doses of phosphorus, magnesium, calcium and omega-3 fatty acids (2).
Chia seeds are also rich in antioxidants, which are compounds that provide protection from oxidative stress and reduce the risk of chronic disease (3).
Thanks to their excellent nutrient profile, chia seeds have been associated with many health benefits.
In one study, a diet including nopal cactus, soy protein, oats and chia seeds was found to decrease body weight, blood triglycerides and inflammation (4).
Additionally, chia seeds are one of the best plant-based sources of omega-3 fatty acids, which have been shown to help increase “good” HDL cholesterol, decrease “bad” LDL cholesterol, reduce blood triglycerides and alleviate inflammation (5, 6).
When consumed in moderation, chia seeds can benefit your health.
Summary: Chia seeds are rich in fiber, protein, omega-3 fatty acids, antioxidants and micronutrients. They may aid weight loss and help reduce inflammation, blood cholesterol and triglycerides.
Chia seeds are a good source of fiber, providing 11 grams of fiber in each 1-ounce (28-gram) serving (2).
Fiber is essential for your health, promoting regularity and supporting the beneficial bacteria in your gut, among other important roles. However, too much fiber can cause issues for some people (7, 8).
Excessive fiber intake can cause problems like abdominal pain, constipation, diarrhea, bloating and gas (9).
This can also occur when a high fiber intake is paired with inadequate hydration, since water is essential to helping fiber pass through the digestive system.
Furthermore, those with inflammatory bowel diseases like ulcerative colitis or Crohn’s disease may need to monitor their fiber intake and limit chia seeds during flare-ups.
Studies indicate that a high fiber intake may help protect against inflammatory bowel diseases in the long term. That said, those who are experiencing flare-ups should limit their fiber intake for short periods to reduce symptoms (12).
However, for most people, negative symptoms from high fiber intake can be prevented by increasing fiber intake slowly and drinking plenty of water to help it pass through the body.
Summary: A high fiber intake may be associated with negative digestive symptoms like abdominal pain, gas and bloating. Those with inflammatory bowel diseases may need to limit their fiber intake during flare-ups.
Though they’re safe for most people, chia seeds may cause an increased risk of choking. So make sure you consume them carefully, especially if you have difficulty swallowing.
This increased risk is because dry chia seeds swell up and absorb about 10–12 times their weight in liquid when they are exposed to water (13).
These gelling properties can be useful when it comes to cooking or baking, but they have the potential to be unsafe, as chia seeds can easily swell up and become lodged in the throat.
One case study discussed a 39-year-old man who had a dangerous incident with chia seeds when he ate a tablespoon of dry seeds and then drank a glass of water.
The seeds expanded in his esophagus and caused a blockage, and he had to visit the emergency room to have it removed (14).
Always make sure you soak chia seeds for at least 5–10 minutes before you eat them. Those with difficulty swallowing may need to exercise extra caution when eating them.
Summary: Chia seeds are able to absorb 10–12 times their weight in liquid. If they’re not soaked before you eat them, they may expand and cause a blockage, increasing your risk of choking.
Chia seeds contain a good amount of alpha-linolenic acid (ALA), a type of omega-3 fatty acid that is found primarily in plant foods (2).
These are the two active forms of omega-3 fatty acids, and they can be found in seafood.
Although omega-3 fatty acids are generally recognized as beneficial for health, some studies have found an association between ALA intake and prostate cancer.
In fact, a large observational study including 288,268 men showed that ALA intake was associated with an increased risk of advanced prostate cancer (17).
Another observational study showed that those with the highest blood concentrations of omega-3 fatty acids had a higher risk of prostate cancer, compared to those with lower blood concentrations (18).
However, studies on this are conflicting. Other research has also found that ALA fatty acids may protect against prostate cancer.
One review of five studies found that people who ate at least 1.5 grams of ALA per day had a decreased risk of prostate cancer, compared to those who ate less than 1.5 grams per day (19).
Similarly, another large study in 840,242 people showed that a higher ALA intake was associated with a lower risk of prostate cancer (20).
It’s important to remember that these studies looked only at the association between ALA intake and prostate cancer. They didn’t take into account other factors that could have played a role.
Further studies are needed to examine the possible relationship between ALA intake and prostate cancer.
Summary: Some studies have found that increased ALA intake may be associated with an increased risk of prostate cancer, while others have found ALA may be protective. Further research is needed.
Some people may experience an allergic reaction after eating chia seeds, though this is uncommon.
Food allergy symptoms may include vomiting, diarrhea and itching of the lips or tongue.
In severe cases, food allergies can even lead to anaphylaxis, a life-threatening condition that causes difficulty breathing and tightness in the throat and chest (21).
Chia seed allergies are rare but have been documented.
In one case, a 54-year-old man began eating chia seeds to help lower his cholesterol. However, just a few days later, he began experiencing dizziness, shortness of breath, hives and swelling (22).
If you try chia seeds for the first time and experience any symptoms of a food allergy, discontinue use immediately and consult your doctor.
Summary: Some people are allergic to chia seeds and may experience symptoms like gastrointestinal distress, itching, hives and swelling after eating them.
While chia seeds are safe for most people, you may want to moderate your intake if you are taking blood sugar or blood pressure medications.
That’s because eating too many chia seeds could potentially interact with the effects of some of these medications.
This is likely due to the high amount of fiber in chia seeds, which slows the absorption of sugar in the blood and can decrease blood sugar levels (24).
In most cases, eating moderate amounts of chia seeds can help people with diabetes keep their blood sugar levels in check.
However, dosages for insulin are personalized and carefully adjusted to prevent dips and spikes in blood sugar (25).
Eating an excessive amount of chia seeds could cause blood sugar levels to decrease and may require adjustments in the dosage of your diabetes medication.
Blood Pressure Medications
In addition to lowering blood sugar, chia seeds are effective at reducing blood pressure.
In one study, eating chia seeds for 12 weeks decreased blood pressure, along with markers of blood sugar and inflammation (26).
This is because chia seeds are high in omega-3 fatty acids, which have been shown to work as a blood thinner and may decrease blood pressure.
A study in 90 people with high blood pressure found that taking omega-3 fatty acid supplements for eight weeks decreased systolic blood pressure by 22.2 mm Hg and diastolic blood pressure by 11.95 mm Hg, on average.
However, the people in this study were also on dialysis, so these results may not be applicable to the general population (27).
Those with high blood pressure might find chia seeds’ ability to decrease blood pressure desirable. However, chia seeds may enhance the activity of blood pressure medications, which could lead to hypotension, or low blood pressure.
Summary: Chia seeds can lower blood sugar and blood pressure. People on medications for high blood pressure or diabetes should moderate their portion sizes to prevent interactions.
Chia seeds are highly nutritious, boast a long list of health benefits and can be a healthy dietary addition for most.
However, moderation is key, as eating too many may cause side effects.
To prevent this, start with 1 ounce (28 grams) daily and assess your tolerance before slowly increasing your intake.
Also, stay hydrated as you increase your fiber intake, and soak chia seeds for 5–10 minutes before eating them.
If you eat them in moderation, chia seeds can be an excellent addition to a healthy and balanced diet.
However, if you experience any negative symptoms after you eat chia seeds, stop eating them and consult a healthcare professional.