Prefer White to Whole Wheat Bread? Your Gut Says It’s Okay

Researchers have found that individual reactions to bread can be determined by examining gut bacteria and for some people, white bread is better than whole wheat.

This may seem like a ridiculous question. After all, everyone knows that the nutrients and fiber in whole wheat bread are good for your health, while white bread contains simply empty carbs and useless calories.

Well, we may actually have it a bit more wrong than you’d expect. As a new study from the Weizmann Institute found, white bread may be healthier than whole wheat bread for certain people.

Researchers conducted a comprehensive, randomized trial involving 20 healthy people, all of whom consumed roughly 10% of their daily calories from bread. Ten of the participants were told to eat processed, packaged white bread for a week, and were ordered to increase their bread intake to 25% of their daily calories. The other 10 participants were given whole wheat sourdough bread in the same quantities. After a two-week resting period (involving no bread consumption), the groups had their diets reversed.

To determine the effects of the bread consumption, the researchers analyzed morning glucose levels, essential mineral (iron, calcium, and magnesium) levels, cholesterol levels, fat levels, liver enzymes, kidney enzymes, and inflammation and tissue damage markers. The participants’ gut microbiomes were also measured to determine their makeup.

Their discovery was shocking: neither of the bread types caused significant clinical differences in the participants. None of the markers—inflammation, mineral levels, cholesterol or fat levels, liver and kidney enzymes, or gut microbiomes—were significantly affected by white or whole wheat bread. In fact, the researchers found that some of the participants actually had a better glycemic response to the white bread than the whole wheat sourdough.

Does that mean white bread is healthier than whole wheat bread? Compare the nutritional content of the two, and you’ll have a hard time finding a nutritionist who will agree with that particular statement. However, what’s fascinating about this study is that it highlights something important: everyone processed food and nutrients differently.

The gut microbiome composition of each person is different, according to our environments, the foods we eat, and our lifestyle. Understanding that nutrition is something specific to each person puts the responsibility of eating healthy squarely in our laps. Instead of accepting the norms at face value, it’s vital that we take control of our diets and learn what works for our bodies and what doesn’t. By being more aware of our unique nutritional needs and capabilities, we can take steps to improve our diet and overall health by making smarter, healthier food choices.


1. Eran Segal et al., “Bread Affects Clinical Parameters and Induces Gut Microbiome-Associated Personal Glycemic Responses,” Cell Metabolism, doi:10.1016/j.cmet.2017.05.002, published 6 June 2017.