Whole wheat sourdough is one of the healthiest forms of bread.

We’ve all been told since we were capable of eating solid food that whole wheat bread is healthier than white bread, and through examination of its nutritional content (fiber and protein content, vitamin and mineral composition, glycemic index, etc.), that belief can hardly be contested. But a recent study examined the effects of consuming different types of bread on biomarkers of health, and the results are probably not what you expected.

In a study published in the June 2017 issue of Cell Metabolism, researchers examined the effects of consumption of industrially-made white bread and handmade sourdough-leavened whole-grain bread on various clinical parameters of health, including glycemic and gut microbiome response. The randomized crossover trial included 20 healthy participants who (based upon a pre-trial food survey) normally consumed approximately 10 percent of their daily calories in the form of bread. The participants were separated into two groups and asked to increase their consumption of bread to around 25 percent of their daily caloric intake for the two separate trial periods. The initial trial period lasted one week, then participants were asked to not eat any bread for two weeks, and then the diet groups were reversed for one more trial week. Prior to the initial trial period and ongoing throughout the four-week study, various parameters of health were monitored, including blood glucose levels, serum triglyceride and cholesterol levels, levels of various minerals, biomarkers of inflammation, and microbiome composition (levels of good and bad bacteria in the gut). According to the researchers, and the data (yes, I double-checked), there was no clinically significant generalizable differences in the health markers throughout the trial based on the type of bread they consumed. There were noted changes, but they were all highly individual. Of particular interest, despite the industrially-made white bread having a higher glycemic index than that of the handmade sourdough-leavened whole-grain bread, nearly half the participants actually had less of a glycemic response to the white bread. Similarly, despite the sourdough bread containing much higher levels of friendly bacteria, such as a Lactobacillus, gut microbiota composition changes were participant-specific and overall bacterial population was resilient regardless of dietary modifications.

For you, the health-conscious consumer, this doesn’t mean that you should throw away the breadth of nutritional science, it simply provides more evidence of my prevailing ideology: there is no ideal diet for everybody. The reality is that different people respond to different foods…differently. Once you understand the basics of thermodynamics (the importance of how much you eat) and commit to focusing the majority of your intake on whole, nutrient-dense food, the perfect diet for you and your goals isn’t going to come from the inside of a magazine, but from the inside of you and your own experiences—namely, how you feel. One-size-fits-all approaches to nutrition simply don’t work. After decades of being my own guinea pig, I’ve found that I have some adverse reactions to some of the healthiest foods. For instance, I really enjoy fruit (of all varieties), but my body does not respond normally to fructose. No matter how fibrous or low glycemic the fruit, I can be just about guaranteed that even the smallest serving will send me into an outwardly visible blood sugar rollercoaster. Halfway through a cup of fresh blueberries and I can already feel the glucose spike. Now, it doesn’t stop me from occasionally imbibing, but I am aware that the end result will be the inevitable food coma and I am likely to be paying for it well into the following day. Likewise, recent studies have shown that some people actually experience a drop in blood pressure due to high intakes of salt and that for a large percentage of the population, dietary cholesterol has very little (or no) connection to serum cholesterol levels.

When designing your own ideal diet, you need to spend less time reading about the diets of the top fitness models and yes, maybe even the primary scientific research, and take more time considering how specific foods and meal-timing patterns make you personally look and feel. Does breakfast energize you throughout the day and prevent you from overeating at lunch, or does it give you digestive discomfort? Are kale and broccoli the low-calorie superfoods their nutritional content suggests, or do those cruciferous vegetables cause you to retain water like a pufferfish (due to their high level of raffinose, this is actually a common thing)? I wish I could tell you, and you know I would, but I am not you. Optimum health is a matter of getting to know your own body and learning to trust how the foods you eat make you feel.          

Dr. Damian Rodriguez is the health and exercise scientist for doTERRA International, LLC. He holds a doctorate in health science, a master’s degree in exercise physiology, and countless professional certifications. He has spent most of his life researching nutrition, exercise, and the lifestyle behaviors associated with optimal health. Along with his passion for health, as someone who lives with Asperger’s Syndrome, he is also involved in bringing awareness to autism spectrum disorders. There are varying opinions about many health and fitness topics. His opinions are his own and not necessarily that of doTERRA International, LLC. Consult your healthcare provider before making any changes to diet and exercise.