Is Costco Sourdough Bread Healthy? Here's What To Know

Costco is one of those retail landmarks where you can find just about any grocery item, including some truly weird stuff (a 72-pound wheel of cheese, anyone?). However, some of the foodie options are probably better for your health than others. After all, a calorie-laden and sodium-filled Costco chicken bake may seem like a great find for a last-minute lunch, but it might not fit a heart-friendly lifestyle. (Check out more of the unhealthiest foods you can order at a Costco food court.)

What about that big old crusty Costco sourdough loaf? Surely it has more nutritional benefits than a mammoth 710-calorie slice of Costco's food court pizza. That said, whether or not you should consider Costco sourdough healthy depends on your diet and fitness goals, as well as any food sensitivities or allergies you might have.

Let's start with what could be considered "good" for you in this bread. To begin with, Costco sourdough is made using a sourdough starter. That's a huge bonus, since many commercial breads labeled as sourdough only use yeast and sour flavoring to give the impression of sourdough without having to wait for a traditional sourdough rise. (Full disclosure: Less than 2% of both yeast and yeast extract are included as ingredients, but sourdough starter is listed toward the top.)

With a genuine sourdough starter, you can be sure you're getting the advantages that come from the starter fermentation process. For instance, fermented bread produces less of an effect on blood sugar levels than yeast-based breads do, according to findings from a 2024 review in Critical Reviews in Food Science and Nutrition. This makes it a low glycemic index (GI) food, which is important if you're monitoring your sugar intake. (If you're interested, the GI for wheat sourdough is 54, which means it isn't as likely to spike your sugar.)

Sourdough is also lower in gluten than several other types of bread because of all that fermentation. As a result, it may be an acceptable bread for individuals who can tolerate limited amounts of gluten. Another win is Costco sourdough bread's unexpectedly high amount of protein. Every serving contains 5 grams of protein, which can keep you from feeling hungry too soon. Interestingly, foods that have a lower GI are also associated with higher satiety. Consequently, eating sourdough bread may advance your efforts to avoid overeating.

Of course, Costco sourdough comes with a few downsides, starting with the flour used to make it. Though Costco sourdough uses enriched wheat flour, it's not among the healthiest flours you can use for baking. Enriched flour means that some of the vitamins and minerals that were taken out during processing were put back. Nice, but what about the fiber that was taken out at the same time? Sadly, it's mostly gone, except for 0.5 grams in each serving, courtesy of some rye flour.

Another issue with this Costco favorite is that the bread may not be right if you exhibit signs that you go gluten-free (e.g., gastrointestinal discomfort, respiratory issues, and itchy skin). The same holds if you have sensitivities to milk, soy, tree nuts, peanuts, or sesame, as this sourdough may put you at risk of a reaction because of cross-contamination, according to its allergen warning.

In other words, Costco sourdough bread isn't perfect. Nonetheless, it may be the right bread choice for you if you like its advantages and don't feel that its disadvantages are deal breakers.