“Salt is an essential nutrient, and this is why we crave it. However, we consume more than we should, just like sugar and fat. Salt is related with hypertension and other cardiovascular diseases, but it’s the amount that is the problem, not the salt itself,” Lee notes.

Salt is also an essential ingredient in bread making; it contributes to the structure and flavor of the bread, and is necessary for the yeast to work properly.

Dunteman and Lee conducted an extensive review of academic literature on sodium reduction in bread. They identified four main categories: Salt reduction without any further mitigation, physical modification, sodium replacements, and flavor enhancers. They discuss each of these methods in their paper, published in the International Journal of Food Science and Technology.

“The most basic method is just reducing the amount of salt in the product,” Dunteman says. “That can be good to a point, depending on the original level of salt and equivalent in the recipe. There's always going to be a minimum amount of salt you need just to have the bread function and the yeast do its job. So it’s a limited method, but it can help to reduce high levels of sodium intake.”

Another method is physical modification, which involves uneven distribution of salt in the product.

“Sensory adaptation occurs when you have constant stimulus. If the salt is evenly distributed in a slice of bread, as you take more bites, it's going to taste less salty, because you're already adapted to the first few bites. But if you have different distribution of salt, alternating between densely and lightly salted layers, people will perceive it as more salty. So you can obtain the same taste effect with less salt,” Lee explains.

A third method involves replacement of sodium with other substances, such as magnesium chloride, calcium chloride, or potassium chloride. “This is one of the most commonly used methods in industry, but it can only be used up to a certain point, before you get a bit of a metallic taste from these compounds,” Dunteman points out.

The fourth method involves flavor modification with taste enhancers such as herbs and spices, or even monosodium glutamate (MSG). The researchers note multi-grain bread also allows for more salt reduction than white bread, because it has more flavor on its own.

Dunteman and Lee conclude the best approach to sodium reduction in bread will be a combination of methods.

“One of the four categories, salt reduction, is technically involved in all of them,” Dunteman notes. “Another category, salt replacement, is already heavily studied. We recommend more research into physical modification methods, as well as flavor enhancement types, and how to combine each of these methods with salt reduction.”

Finally, the researchers have some advice for home bakers looking to reduce sodium in their creations.

“If you're interested in using less salt in your home-baked bread, you could try to reduce the amount to 50%, if you're using standard recipes that are widely available,” Lee says. “You’d be surprised that the dough would still rise, though the bread would taste a little different. You can also use flavor enhancers to provide the salty, savory, satiating sensation you lose when you reduce the salt. But that wouldn’t help with the rise, so you cannot remove salt 100%.”

The research was supported by the Institute for the Advancement of Food and Nutrition Sciences (IAFNS) through an ILSI North America Sodium Committee grant. IAFNS is a non-profit science organization that pools funding from industry collaborators and advances science through the in-kind and financial contributions from public and private sector participants. IAFNS had no role in the design, analysis, interpretation, or presentation of the data and results.