Whole-Wheat Bread May Only Be Better Than White for Some People

A member of the sales staff stands in the bakery section as Italian supermarket chain Esselunga opens its first store in Rome, 2017. A wide variety of breads are stocked there. Simona Granati/Corbis via Getty Images

Good news for those who consider white bread to be a sinful indulgence: Depending on your body, it might be as good or better for you than the whole-wheat variety. This finding could revolutionize the way we look at bread products, as it flies in the face of one of the most prevalent nutritional opinions out there, that whole-wheat bread is superior to white bread.

Don't go tossing out the brown stuff just yet, however. This opinion stems from the results of a recent small-scale study published in the journal Cell Metabolism. Although intriguing and certainly worth investigating further, the study looked at a group of only 20 participants over a period of several weeks to see how each type of bread (processed, packaged white bread and fresh-baked daily artisanal wheat sourdough) affected them physically.

This visual abstract shows the findings of Korem et al. who performed a crossover trial of industrial white or artisanal sourdough bread consumption and found no significant difference in clinical effects, with the gut microbiome composition remaining generally stable. They showed the glycemic response to bread type to be person specific and microbiome associated, highlighting the importance of nutrition personalization.
Korem et al./Cell Metabolism 2017

Participants were supplied with one type during the first week of the research, then took a two-week hiatus from all bread consumption, then were supplied with the other type for another week. Researchers monitored a number of bodily reactions throughout the process, including glucose levels at wakeup, inflammation and tissue damage markers, and levels of certain essential minerals, such as magnesium, calcium and iron. They also monitored cholesterol and fat, as well as liver and kidney enzymes.

Researchers also looked at each participants' individual microbiome make up. The microbiome is made up of the genetic material of fungi, bacteria, viruses and protozoa. The health of the microbiome can beneficially or adversely affect a person's overall wellness.

The overall findings showed that the participants were not greatly impacted by the type of bread they consumed. No one was more surprised by this revelation than the researchers themselves. "The initial finding, and this was very much contrary to our expectation, was that there were no clinically significant differences between the effects of these two types of bread on any of the parameters that we measured," says Eran Segal, senior author and computational biologist at the Weizmann Institute of Science in Israel, in a press release.

The researchers suspected this might have something to do with each participant's glycemic response to bread. Indeed, when they looked more closely at the data, it showed that some people had a better glycemic response to one type of bread or the other. Roughly half responded more favorably to white flour bread, and the other people's bodies reacted better to the whole-wheat bread.

"The findings for this study are not only fascinating but also potentially very important because they point toward a new paradigm: Different people react differently, even to the same foods," says Eran Elinav, another senior author and researcher in the department of immunology at the Weizmann Institute. "To date, the nutritional values assigned to food have been based on minimal science, and one-size-fits-all diets have failed miserably."

Whole-wheat bread is generally considered to be better for you than white bread because it has more nutrition and fiber. The scientists note that much more research needs to be done around their study.