You might have heard chia and flax described as “superfoods.” It’s an apt term because both types of tiny seeds are packed with vitamins, minerals and other nutrients that can improve your health and help you ward off disease. While chia and flax have many similarities, a few key qualities distinguish them.
A typical serving of either chia or flaxseeds is a 1-ounce portion, which is equivalent to just over 28 grams. In that amount of chia seeds, there are about 140 calories, 5 grams of protein, 9 grams of fat, 12 grams of carbohydrates and 10 grams of fiber. The same amount of flaxseeds has about 150 calories, 5 grams of protein, 12 grams of fat, 8 grams of carbohydrates and 8 grams of fiber.
How They're Similar
Flaxseeds and chia seeds are both healthy sources of omega-3 fatty acids, with about 2,400 milligrams of omega-3s per tablespoon of seeds. Omega-3s are a type of unsaturated fat that may protect against stroke, heart disease, cancer, inflammatory bowel disease and autoimmune diseases. Chia and flax are also similar in size and in texture. Chia seeds are digestible either whole or ground, but the tough outer coating on flaxseeds means they need to be ground before you use them. Whole flaxseeds pass through the body undigested.
How They're Different
Nutritionally, one trait that distinguishes chia from flax is chia's relatively high calcium content. One ounce of chia seeds has about 180 milligrams of calcium, while the same amount of flax has just 75 milligrams. Flax, however, edges out chia when it comes to lignan, a type of fiber that can play a role in preventing breast and prostate cancer. If you’re vegan, you may want to favor chia seeds over flax, since their protein contains every essential amino acid. This is rare for a plant-based food.
Both chia and flax can act as thickeners or binding agents in recipes. They are especially useful in vegan recipes, where eggs would normally do the work of holding a batter together. To replace one egg, whisk 3 tablespoons of water with 1 tablespoon of chia seeds or ground flax. If you’re subbing one for the other, be aware that chia seeds can take longer to absorb liquid and become gelatinous. Flax mixed with liquid will thicken up in two to three minutes, but chia seeds can take a half hour or longer.