We’ve often been told that processed white bread is not good for our diet, but a team of scientists claim that might not be the case.
Researchers at Israel’s Weizmann Institute of Science suggest there are no “significant differences” in white and brown bread, because individuals react differently to food and, for some people, white bread can be just as effective as brown bread.
However, their research was conducted over a short period of time and is based on only 20 volunteers, which is too small a sample for the findings to be deemed conclusive.
The researchers monitored the participants’ gut bacteria and levels of fat, as well as cholesterol, glucose and essential minerals.
Half of them were given increased amounts of fresh whole-wheat sourdough bread to consume for a week, while the rest were given the same portion of processed white bread.
“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,” study author Professor Eran Segal said.
“We looked at a number of markers, and there was no measurable difference in the effect that this type of dietary intervention had.”
Prior to the study, the volunteers ate an average amount of bread – amounting to around 10% of their daily calories.
After the week of consuming either processed white or brown bread for around 25% of their calories, the participants took a two-week break and then reversed their diets.
The researchers said they found some people had better responses to white flour bread while others reacted better to the whole wheat alternative.
They believe this is down to the individual’s glycaemic responses – which measures the effect a food or meal has on blood sugar (glucose) levels after consumption and is dependent on the blend of microbes found in the gut.
But overall, there was very little difference between effect of the two types of bread.
“The findings for this study are not only fascinating but potentially very important, because they point toward a new paradigm: different people react differently, even to the same foods,” said senior researcher Dr Eran Elinav.
The research is published in the journal Cell Metabolism.