Flaxseeds: Nutrition, Omega-3s, Glycemic Index & How to Use Them

The tiny seed powerhouse

Flax is one of the oldest crops in the world, originally grown for its fiber to make linen. But the real magic is in the seeds. They come in two main colors, brown and golden, which are nutritionally almost identical. What matters more than color is the form: whole or ground.

Whole flaxseeds have a tough outer shell that our bodies can't break down easily. If you eat them whole, they're likely to pass right through you, taking their valuable nutrients with them. To get the benefits, you need to crack them open. This is why you'll hear dietitians like me going on and on about using ground flax.

Flaxseed nutrition facts

Here’s the nutritional profile for 100 grams of flaxseed. It's a large amount — about 10 tablespoons — but it's the standard for comparison. A more typical serving is one or two tablespoons.

Why you must grind them

I can't say this enough: your body gets very little from whole flaxseeds. Their tough hulls are designed to survive digestion so the seed can be spread. Grinding them breaks this hull and exposes the nutrient-rich interior, including the precious omega-3 fatty acids and lignans.

You can buy pre-ground flaxseed (often called flax meal), which is convenient. But the fats in flax are delicate and can go rancid when exposed to air and light. For this reason, buying whole seeds and grinding small batches at home in a coffee or spice grinder is the gold standard. Store any ground flax—and your whole seeds—in an airtight container in the fridge or freezer to keep them fresh.

Flaxseed's glycemic index

The glycemic index (GI) of flaxseed is so low it's often not even formally measured. Why? Because it contains almost no starch or sugar. Of its 28.9 grams of carbs per 100g, a whopping 27.3 grams are fiber. This means the 'net carbs'—the ones that impact blood sugar—are incredibly low. The high fiber and fat content also act as a brake, slowing down the digestion of any other carbs you eat with them. For managing blood sugar, it's one of the best things you can add to your plate.

How to actually use them

Getting more flax into your diet is easy once you get into the habit. Remember to start small (say, a teaspoon) to let your digestive system adapt to the extra fiber, and drink plenty of water.

What flaxseed is good for

What to pair flaxseed with

Flaxseed's nutty flavor is mild and versatile. It works best when stirred into wet ingredients, where it can absorb liquid and contribute to a pleasant texture.

Who should eat flaxseed?

Three simple ways to use it

No complex recipes needed. Here are three everyday ways to make ground flaxseed a regular habit.