After an explosion in sourdough bread-making during the pandemic lockdown era, the naturally leavened bread remains a favorite among many, and for good reason. But is sourdough bread healthy?
Sourdough is often hailed as a superfood and healthier option compared to normal bread. It's a staple of the meal that the world's longest-living family eats every day, and it may be easier on the digestive system for some people.
So, is sourdough healthier than regular bread? Does it have any health benefits? We spoke to experts to find out.
What is sourdough bread?
Regular bread is made with commercial or baker's yeast (a species of fungi called Saccharomyces cerevisiae), which allows the bread to rise, Josephine Wee, Ph.D., an assistant professor of food science at Penn State University, tells TODAY.com.
The yeast is activated and mixed with water, flour, salt and other ingredients, which are kneaded into a dough and then baked.
Sourdough bread is made with a "starter" culture — made from fresh flour and water — which contains wild yeast and live bacteria instead of baker's yeast, Wee explains.
The community of wild yeasts and bacteria in a sourdough starter are naturally-occurring in the environment — they come from the flour and water used to make the starter, the kitchen it was made in and the air, Charlene Van Buiten, Ph.D., an assistant professor of food science at Colorado State University, tells TODAY.com.
The sourdough starter microbiome includes lactic acid bacteria and acetic acid bacteria, says Wee, which is what gives the bread its signature sour, tangy taste.
The starter is left in jar to ferment, says Van Buiten, which can take up to a week or longer. The fermentation process creates carbon dioxide, says Van Buiten, which leavens the bread naturally.
When the starter is ready, it's mixed into the dough, which is allowed to rise and baked. Sourdough is often chewier and more complex than regular bread, the experts note.
Since everyone lives in different microbial environments, every sourdough starter is different, says Wee. This can affect the taste, rise, texture and crust of the bread. So think of every loaf as unique and special in its own way.
Sourdough bread nutrition
The nutritional information for sourdough bread will vary depending on the type of flour used, other added ingredients, preparation and the brand.
According to the U.S. Department of Agriculture‘s FoodDATA Central database, one serving (about 50 grams or one medium slice) of the average loaf of sourdough bread provides about:
- 130 calories
- 4 grams of protein
- 1 gram of fat
- 25 grams of carbohydrates
- 1 gram of fiber
- less 1 gram of sugar
- 200-300 milligrams of sodium
Sourdough bread provides vitamins and minerals, including vitamin B, iron and calcium, and is a great source of antioxidants and prebiotics, as well, the experts note.
Is sourdough healthier than regular bread?
Sourdough bread does have health benefits that regular bread may not have. These include:
- Higher in nutrients
- Raises blood sugar slowly
- Easier to digest
- Supports gut health
Health benefits of sourdough
The type of flour used — all-purpose, whole wheat, rye — can affect the nutritional content of sourdough bread, says Wee. But generally speaking, sourdough bread is a healthy option and can be eaten regularly as part of a nutritious, balanced diet.
The fermentation process and preparation of sourdough leads to a variety of benefits, says Van Buiten. First, sourdough bread naturally has higher levels of nutrients than regular bread.
"Fermentation can improve mineral (and vitamin) bioavailability in sourdough bread compared to conventional bread," says Van Buiten. This occurs due to an enzyme produced by bacteria during fermentation called phytase, which breaks down phytic acid, an "anti-nutrient" that can reduce the absorption of vitamins.
Weight loss and management
Sourdough also contains higher levels of resistant starches, the experts note. These are a type of carbohydrate that "resist" digestion and take much longer for the body to break down, which can help control hunger and with weight management, TODAY.com previously reported.
Keeping blood sugar steady
Sourdough has a lower glycemic index than regular bread, says Van Buiten. Foods with a low glycemic index raise the blood sugar in a slower, steadier way. This is why sourdough takes longer — but is easier — to digest.
Boosting gut health
Sourdough bread has more soluble fiber than regular bread, which means it has prebiotic qualities and can be good for gut health, says Van Buiten.
The probiotics and live cultures in unbaked sourdough will get killed by the heat during the baking, Frances Largeman-Roth, a registered dietitian nutritionist, tells TODAY.com. However, the prebiotics that survive will act as food for probiotics and support the growth of healthy bacteria in the gut.
More resistant to mold
Another benefit of the sourdough fermentation process? The acids produced by bacteria lower the pH of the bread, which prevents the growth of food-borne pathogens, per the American Society of Microbiology. Sourdough bread has the potential to stay shelf-stable for longer and be more resistant to mold, says Van Buiten.
Less gluten may make it easier to digest
Gluten, a protein found naturally in wheat, barley and rye, becomes degraded during the fermentation process when making sourdough bread, says Van Buiten, so it naturally contains less gluten than other types of bread.
As a result, sourdough bread can be easier to digest, especially for people who have a gluten sensitivity or intolerance, says Wee. It may also be better tolerated than regular bread if you have other digestive issues, like irritable bowel syndrome.
However, sourdough bread is not gluten-free, so people with celiac disease or a gluten allergy should avoid sourdough bread (and other gluten-containing products). Speak to a doctor if you have questions.
How to choose a sourdough bread
All types of sourdough are relatively healthy, says Largeman-Roth, but the healthiest type of bread — sourdough or otherwise — is whole wheat or whole grain.
Whole-grain bread is made with flour containing the entire wheat kernel. “The whole-grain sourdoughs have more fiber, protein and micronutrients, making them more filling and healthier for you overall,” says Natalie Rizzo, registered dietitian and nutrition editor at TODAY.com.
When choosing a sourdough loaf, look for ones that have whole wheat, spelt or rye, Rizzo adds. Some studies suggest that Einkhorn wheat, a type of "ancient grain," may offer more nutritional benefits.
When comparing nutrition labels, try to opt for the one with fewer ingredients and less sodium and sugar. Alternatively, you can always try making your own starter and baking sourdough bread at home.