Chia Seeds vs. Flax Seeds: Is One Healthier Than the Other?

Although chia and flax seeds differ in their nutrient profiles, both can contribute to improved health. Chia seeds provide more fiber, while flax seeds are richer in certain antioxidants.

In recent years, some seeds have earned reputations as superfoods. Chia and flax seeds are two prominent examples.

Both are densely packed with nutrients and have been associated with benefits such as improved cardiovascular health, better blood sugar control, and potential protection against specific cancers.

Many people ask which of the two is superior for health. This article reviews the evidence to help answer that question.

How do chia seeds and flax seeds differ?

Chia seeds are tiny, oval seeds that come from the Salvia hispanica plant, commonly called the chia plant. Also referred to as salba seeds, they are typically sold whole and appear in black and white varieties.

Native to Mexico and Guatemala, chia seeds were likely a staple in the diets of ancient Aztec and Mayan civilizations.

By comparison, flax seeds are flatter and a bit larger. Also known as linseeds, they usually come in brown or golden shades, can be purchased whole or ground, and are believed to have originated in the Middle East.

Chia seeds have a fairly neutral taste, while flax seeds carry a mild, nutty flavor. Both are easy to mix into many recipes.

Nutritional comparison

Both chia and flax seeds are loaded with a variety of nutrients.

The following compares major nutrients per 1-ounce (28-gram) serving, roughly 4 tablespoons, for each seed.

Flax seedsChia seedsCalories150138Carbs8 grams12 gramsFiber8 grams10 gramsProtein5 grams5 gramsFat12 grams9 gramsThiamine38% of the DV15% of the DVMagnesium26% of the DV23% of the DVPhosphorus5% of the DV5% of the DVCopper38% of the DV29% of the DVSelenium13% of the DV28% of the DVIron9% of the DV12% of the DVZinc11% of the DV12% of the DVCalcium6% of the DV14% of the DVPotassium5% of the DV2% of the DV

Both seeds deliver a respectable amount of protein and plant-based omega-3s, with flax seeds offering slightly more omega-3 content.

Flax seeds are notably higher in copper and thiamine.

Chia seeds are marginally lower in calories and higher in fiber. They also contain almost 2.5 times the calcium that supports bone health, along with slightly higher iron and phosphorus content.

Both may reduce heart disease risk

Chia and flax seeds are both good sources of alpha-linolenic acid (ALA), a plant-derived omega-3 fatty acid.

ALA is essential because the body cannot synthesize it, so it must be obtained through diet. Multiple studies indicate that ALA may lower heart disease risk.

Regular consumption of chia and flax may enhance heart health by helping to decrease:

• blood pressure
• low-density lipoprotein (LDL) cholesterol
• oxidative stress

Owing to their omega-3 content, both seeds may also reduce clot formation and have a mild blood-thinning effect. People on anticoagulant medications should speak with a healthcare provider before consuming large amounts of these seeds.

Both help manage blood sugar

Both chia and flax seeds may lower some risks linked to metabolic syndrome and type 2 diabetes.

Both are good sources of fiber, which is associated with a reduced risk of developing type 2 diabetes. Fiber slows carbohydrate digestion and the absorption of sugars into the bloodstream, producing a more gradual rise in blood glucose after eating and preventing sharp spikes.

This moderation of blood sugar helps stabilize levels and offers some protection against type 2 diabetes.

Flax seeds might be slightly better at lowering certain cancer risks

Both chia and flax seeds may help defend against cancer through several mechanisms.

First, both are high in fiber, a nutrient generally linked to a lower risk of some cancers.

A 2023 review suggests diets rich in dietary fiber may be associated with reduced risks of these cancers:

• esophageal
• gastric
• colon
• rectal
• breast
• endometrial
• ovarian
• renal cell
• prostate
• pancreatic

Both seeds also provide antioxidants that help lower free radical levels. Free radicals can damage cells and contribute to aging and diseases such as cancer.

When comparing antioxidant content, flax seeds may have an advantage because they are the richest source of lignans, a class of antioxidants with anticancer properties.

Therefore, flax seeds might be somewhat more effective than chia seeds at reducing cancer development risk.

A 2019 review indicates that regular flax consumption may exhibit anticancer effects against certain cancers, including breast cancer and acute myeloid leukemia (AML).

There are fewer studies on chia seeds’ direct influence on cancer risk, but their antioxidants and polyphenols may also help lower that risk.

More research is needed before drawing firm conclusions about which seed is superior.

Both provide several antioxidants with potential cancer-protective effects.

Flax seeds may curb hunger a bit more

Both chia and flax seeds are excellent sources of fiber, which can help suppress hunger and curb cravings. However, they differ in soluble fiber content, the type most effective at promoting satiety and appetite control.

Soluble fiber forms a gel when mixed with water, which delays digestion and increases feelings of fullness.

It also stimulates hormones that regulate appetite, which can further decrease hunger.

About 25% of flax fiber is soluble, while only 7–15% of chia’s fiber is soluble. Consequently, flax seeds may be a bit more effective at reducing hunger and appetite than chia seeds.

Overall, both seeds appear to help reduce appetite, but flax may have a slight edge due to its higher soluble fiber content.

Direct comparative studies are still limited and more research is necessary.

Both support digestion

Digestion is essential for breaking down food and absorbing nutrients.

Poor digestive function can impair nutrient uptake and cause uncomfortable symptoms.

Thanks to their fiber content, both flax and chia seeds can help relieve constipation and manage diarrhea.

Fiber helps clear waste from the digestive tract. While soluble fiber can slow digestion, insoluble fiber adds bulk to stools and may accelerate transit through the intestines.

The insoluble fiber in both seeds can act as a mild laxative, easing constipation.

Meanwhile, the gel-forming action of soluble fiber—more abundant in flax—can help bind digestive waste, which may reduce diarrhea.

How to use chia and flax seeds

Both seeds are versatile and simple to include in your diet. Their mild flavors make them suitable for many dishes.

Whole

Sprinkle them over yogurt, stir them into smoothies or oatmeal, or add them to baked goods. They can also thicken sauces or serve as egg replacements in various recipes.

Most benefits discussed above were observed with about 1–2 tablespoons (10–20 grams) of seeds per day.

Ground

Although both can be eaten whole, grinding them offers advantages.

Whole flax seeds may pass through the digestive tract largely intact because their outer shells are difficult to break down. Consuming them ground can improve nutrient absorption.

Chia seeds are often eaten whole, but research suggests grinding may also enhance nutrient uptake.

Due to their high fat content, both seeds are best stored in the refrigerator or freezer to avoid rancidity. Consume them relatively soon after opening.

Final thoughts

Chia and flax seeds are both nutrient-dense and provide similar benefits for heart health, blood sugar control, and digestion.

Flax seeds seem to hold a slight advantage in areas like appetite suppression and potentially lowering certain cancer risks, and they are often more budget-friendly.

That said, the differences are modest. Including flax seeds, chia seeds, or both in your diet can be a beneficial choice.