Turns Out Chia Seeds and Flaxseeds Aren't Interchangeable. Here's When to Use Each.

Adding chia seeds or flaxseeds to smoothies, protein balls, and oatmeal isn't new. People have been leaning on these seeds for ages to give their recipes more nutrients in a low-effort way, hoping these simple additions can give their bodies a boost of nutrients to support certain aspects of their health.

But while chia seeds and flaxseeds can appear to be interchangeable, there are some noteworthy differences between the two. For one, they look different. Chia seeds are tiny black or white ovals, while flaxseeds are brown and teardrop shaped. They have slight nutritional differences, too.

Because of these differences, you may be wondering which of these two "superfoods" is worth the buy. As a registered dietitian, I have a unique perspective on the topic, and unfortunately, the answer to the chia vs. flaxseed debate isn't black and white.

Kristin Draayer, MS, RDN, is a registered dietitian nutritionist, certified intuitive eating counselor, and certified personal trainer.

Beth Stark, RDN, LDN, is a registered dietitian nutritionist and owner of Beth Stark Nutrition.

Chia and flaxseed may be used in similar ways, but they are two very different seeds.

Chia seeds are tiny black seeds from the plant Salvia hispanica, which is native to Central America. They were an important food for the Aztecs and Mayans and were prized for their ability to provide sustainable energy. Chia seeds have a relatively mild, nutty flavor, making them highly versatile in terms of culinary use. They don't significantly alter the taste of the dishes they're added to. Instead, they tend to absorb the flavors of the foods and liquids they're combined with. This characteristic makes chia seeds a favorite addition to a wide variety of dishes, from adding protein to smoothies and baked goods to salads and yogurts.

Here are the nutrition facts per one ounce of chia seeds, according to the USDA Food Database:

Flaxseeds, on the other hand, originate from the plant Linum usitatissimum and have been a part of human and animal diets for thousands of years. These small, nutty-flavored seeds are renowned for their nutritional profile. Their taste is not overpowering, making them a versatile addition to various dishes.

Here are the nutrition facts per one ounce of flaxseeds, according to the USDA:

Both chia seeds and flaxseeds offer impressive health benefits. For example, they're both sources of omega-3 fats, which support heart and brain health. They're also sources of antioxidants, which help combat oxidative stress (which is associated with the development of several metabolic, chronic disorders or cancers). On top of that, they're also rich in fiber and minerals, says Kristin Draayer, MS, RDN, registered dietitian.

Here are a few of the benefits that both chia and flaxseeds offer.

Sustained Energy and Fullness: The mix of protein, fiber, and healthy fats in both chia and flaxseeds provides a steady energy release, keeping you full longer, Draayer says. "Both types of seeds may play a role in curbing one's appetite between meals because they slow down digestion and promote feelings of fullness," adds Beth Stark, RDN, LDN, a registered dietitian nutritionist and owner of Beth Stark Nutrition. "Similarly, they may help maintain steady blood-sugar levels for those with or without diabetes."

Digestive Health: Chia seeds and flaxseeds are high in both soluble and insoluble fiber, which support a healthy gut and regular bowel movements, Draayer says.

Versatility in Cooking: Chia seeds' unique ability to absorb water and form a gel-like consistency makes them a favorite in puddings and overnight oats and as an egg substitute in recipes. Flaxseeds, especially when ground, can easily be added to baked goods, cereals, and smoothies without altering the taste or texture of the dish.

Yes, chia and flaxseeds have a lot of similarities. But there are some distinct differences between them, too.

For example, chia seeds are higher in fiber, while flaxseeds are higher in fat. Chia seeds contain more calcium, whereas flaxseeds contain more magnesium — two minerals that support bone health. "Chia seeds provide a complete protein source and have an increased fiber content, while flaxseeds offer a higher concentration of omega-3s," Draayer adds.

Another noteworthy thing about flaxseeds is that they're a source of lignans, or a class of plant "estrogens" (phytoestrogens), which research shows may help reduce osteoporosis risk and offer some menopausal symptom relief (like hot flashes).

Chia seeds can be enjoyed as is, while flaxseeds need to be ground, as the outer shell of the flaxseed is hard and can pass through the digestive system undigested if eaten whole, meaning you don't actually get any of the nutrients it offers. By grinding flaxseeds (into what's often called flaxseed meal), you break down this outer shell, allowing the body to access and absorb the rich array of nutrients inside, including those phytoestrogens.

Both chia and flaxseeds are nutritional powerhouses that can be easily added to many dishes you're already eating. Trying to pick which is "healthier" is essentially impossible.

At the end of the day, both chia seeds and flaxseeds are nutrient-packed additions that can help support gut health, bone health, and so much more. Saying one is healthier than the other is like pitting an apple against a pear — both are great choices. As a dietitian, I'm thrilled when clients tell me they add chia seeds, flaxseeds, or both to their overall balanced and healthy diets.

Whether you're now team flaxseed or chia, know that adding either of these seeds to your diet is a positive step to supporting your overall wellness. Of course, you should ultimately lean on your healthcare provider's suggestions, so if they recommend one over the other (or they suggest you stay away from both for unique reasons), it's best to follow their marching orders.

Lauren Manaker is an award-winning registered dietitian and freelance writer who is passionate about providing evidence-based nutrition information in a fun and interesting way.