Chia seeds — the tiny black seeds often added to smoothies and acai bowls — are touted as a “superfood” because they pack quite a nutritional punch. Two and a half tablespoons of seeds contain one gram of fiber and almost seven grams of healthy fats. They are a complete protein, containing all nine essential amino acids, and they are also an excellent source of calcium, zinc, iron, other vitamins and minerals, phytochemicals and antioxidants. Chia seeds are in a group of foods (nuts and seeds) associated with improved blood sugar, lower blood pressure, and improved gut health, so their potential to support health is significant. But what does the science say? Are chia seeds as healthy as they seem? And what are the health benefits of chia seeds, exactly?

Chia seeds and metabolic health

The chia plant has been used for medicinal purposes for thousands of years; however, there is little scientific research on chia seeds themselves and their impact on human health (although there have been many promising studies done on animal models). Nevertheless, there is some research connecting chia seed consumption to a variety of health benefits:

• A recent review assessing results from 10 clinical trials showed that chia seeds can increase “good” (HDL) cholesterol and lower “bad” (LDL) cholesterol. Chia seeds also reduced serum levels of free fatty acids and saturated fatty acids (“bad” fats) and increased polyunsaturated fatty acids (PUFAs; also known as “healthy fats”) — including alpha-linoleic acid (ALA), eicosapentaenoic acid (EPA) and linoleic acid (LA).

• Similarly, serum ALA and EPA levels increased in post-menopausal women consuming chia seeds daily for 7 weeks.

• A 2011 review suggested that chia seeds can help support weight loss; however, a 2014 study on a small cohort of 26 people found that eating chia seeds didn’t help people lose weight.

• A small study on 15 people found that chia seeds were better than flax seeds (another “super food”) at slowing down how fast the body releases glucose, reducing blood sugar spikes.

• Twice-daily supplementation with chia seeds for three months reduced C-reactive protein, von Willebrand factor and systolic blood pressure in a cohort of type 2 diabetes patients. However, there were no differences in blood glucose levels or blood lipid parameters.

What are the health benefits of chia seeds? Fiber, and healthy fats

Perhaps the best advantages of chia seeds are their high levels of both fiber and healthy fats. Most Americans don’t eat enough fiber, and increasing fiber intake is one of the most-promoted ways to increase overall health and well-being. The benefits of a diet high in fiber include:

• Improved gut health
• More stable blood glucose
• Lower inflammation

Healthy fats, such as polyunsaturated fatty acids (PUFAs) and Omega-3 and Omega-6 fatty acids, also play an important supporting role in health. Health benefits include:

• Lower risk of cardiovascular disease
• Improved cognitive function
• Increased insulin sensitivity
• Better weight management
• Lower inflammation

Due to their high levels of both fiber and healthy fats, chia seeds can be a good addition to a varied diet full of whole foods. However, they may not be a good choice for everyone.

What are the potential side effects of chia seeds?

While the high fiber content of chia seeds can seem like a good thing at first glance, too much fiber can be a bad thing for certain individuals. In fact, chia seeds are found on the low-FODMAPS diet black list. FODMAPS are Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols that can contribute to the unpleasant and even painful digestive symptoms experienced by individuals with irritable bowel syndrome (IBS) and other similar gastrointestinal conditions. A growing body of medical providers are advising that individuals test out various FODMAPS foods and then adopt a diet that eliminates or minimizes those particular FODMAPS foods that cause them gastrointestinal distress.

Although rare, chia seed allergies, hypersensitivities and cross-reactions have been noted:

• A 2019 case study reported an individual patient suffering an anaphylactic response to chia seeds. The person had existing allergies to grass pollen and cat dander.

• Chia seeds may be cross-reactive with sesame seeds, causing allergic reactions to chia seeds in people with existing sesame seed allergy.

• Similarly, cross-reactions to plants in the same family as the chia seed plant have been reported.

Additionally, bear in mind that chia seeds are often found as ingredients in baked goods and snack foods that are high in sugar, processed carbohydrates and saturated fats. The negative health impacts of the latter three ingredients could very well offset the potential beneficial effects of the chia seeds — so it's better to eat them as an addition to healthy snacks such as green smoothies or plain, no-sugar-added yogurt. 

Flax seeds are also a great alternative to chia seeds, possessing many of the same beneficial characteristics. Because the fiber content of flax seeds is lower, they may be better tolerated by people with digestive issues. 

Chia seed benefits are only benefits if they are accessible

The potential health benefits of chia seeds matter only if the nutrients they offer are readily available. Because of their tough structures, chia seeds aren’t easily digested. Not only could this lead to some of the digestive issues summarized above, it can also prevent the beneficial nutrients contained within chia seeds from being absorbed by the body. A 2020 study found that nutrient availability is limited when chia seeds are consumed in their native form compared to when they are artificially pre-digested.

The researchers suggested that milling and sprouting should be considered for maximizing the uptake of nutrients and for increasing digestibility. Soaking in water prior to consuming them will also increase the digestibility of chia seeds.

Key Takeaways

Chia seeds are a great source of several key micro- and macronutrients — including fiber, protein, healthy fats, vitamins and minerals and antioxidants. However, chia seeds can cause side effects such as allergies or digestive issues in certain individuals. If you like chia seeds and your system can tolerate them, there is no reason not to enjoy chia seeds as a good, high-fiber addition to a well-rounded diet focused on nutritious whole foods.