Wholegrain, wholemeal, white. In that order, we believe these are the breads from healthiest to unhealthiest.
But new Israeli research published in Cell Metabolism journal has found that white isn’t necessarily the worst. In fact, for some people it can be the best option for overall health.
This may all come down to to an individual’s gut microbiota, it would seem.
The bacteria that is housed in your gut – your microbiome – maintains the health of your intestinal mucosa, playing a big part in your immune system as it performs a barrier effect.
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In this study, researchers had used participants that consumed 10 per cent of their daily calories from bread and looked at microbiomes, levels of glucose, calcium, iron, magnesium, fat and cholesterol, kidney and liver enzymes, and inflammation markers. They were asked to increase their bread intake to 25 per cent of calories for the duration of the study.
The two breads used in the study were plain white and wholegrain sourdough. The former has a high glycemic index and was expected to perform worse on the participants’ health markers. The latter, a low-glycemic bread, was thought to be overwhelmingly healthier.
Researchers were surprised to find that the participants’ gut microbiome composition played a big part in how their bodies reacted to each type of 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,” said Eran Segal, one of the study’s authors.
This was a small study, however – just 20 people in two one-week trials – so we can’t take this too seriously. When the researchers looked deeper into their study’s results, they found that some people with particular microbiomes reacted better to the wholegrain sourdough bread, while others reacted better to the white bread.
When taken as an average, it merely appeared at the end of the study that there was no difference between the breads.
The takeaway from this is that white bread isn’t necessarily going to raise your blood sugar levels more than other bread, if you have a particular makeup of gut microbiomes.
However, we should again stress this is just one small study and can’t be considered doctrine. It also doesn’t counter the myriad of other studies that put wholegrain bread on top.
A recent meta-analysis of 45 studies conducted for The BMJ concluded that it found further evidence that wholegrain consumption is associated with a reduced risk of coronary heart disease, cardiovascular disease, all cancers, and mortality from all causes.