Our food system is upside down because the food industry is more concerned with flattering our taste-buds than keeping us healthy. Nature offers us whole foods that are nutritious and palatable but we prefer them refined, so many aliments are heavily transformed to taste better. The trade-off is the loss of their nutritional value in the process.
Take bread. A major staple food since the beginnings of agriculture 10,000 years ago, bread has turned white over the centuries. White wheat bread has become the standard bread type in many countries and is consumed by millions of people each day. We’ve had it in our plates since our most tender age, so we can hardly believe it could harm us. And yet, there are a whole lot of reasons against incorporating white bread into our diet.
Even though it doesn’t taste sweet, white bread has, in fact, the same effect on your body as plain sugar. It rapidly elevates your glycemia (i.e. blood glucose concentration), thereby forcing your pancreas to release large amounts of insulin to lower it, which short-term wise stimulates fat storage and long-term wise may lead to insulin resistance.
White bread triggers this reaction because it falls in the high glycemic index (GI) foods category―value comprised between 70-100, with 100 corresponding to pure glucose―which should be avoided to prevent severe health conditions like diabetes, obesity and cardiovascular diseases. And if values are so high, it’s because white bread is made of refined, ultra-processed flour obtained by ridding wheat kernels of their germ and bran, leaving only the endosperm for us to eat (see image below).
The endosperm provides plant embryos with the energy they need to develop and germinate. It is primarily composed of starch, a type of carbohydrate quickly digested and absorbed by our guts that raises our glycemia in the process. For this reason, despite being a valuable energy source, wheat starch, hence white flour, is unhealthy for us when eaten alone. These adverse effects disappear when consuming the whole wheat grain. Both germ and bran indeed contain dietary fibers, a type of carbohydrate that slowly transits through our digestive system and keeps our bloodstream sugar level steady all along. As a result, dietary fibers boast a low GI―below 70―that balances out the total carb intake value and thus neutralizes the detrimental effects of starch.
Other than controlling glucose absorption, both soluble (e.g. nuts, oats, rye) and insoluble (e.g. whole grains including the bran) fibers play an essential role in regulating cholesterol and preventing diabetes and colorectal cancer. The minimum daily intake of dietary fibers recommended by the European Food Safety Authority (EFSA) is 25 g, which may seem low but is, in fact, nearly impossible to reach by eating just veggies and fruits.
Eating whole bread greatly helps reaching this salutary threshold. It additionally brings us the essential vitamins, minerals, antioxidant and proteins contained in the germ and bran, which are non-existent in white flour, even enriched (see side image). A recent study by the Harvard Medical School found that “intake of whole grains and cereal fiber may reduce the risk of all-cause mortality and death from chronic diseases such as cancer, CVD [cardiovascular diseases], diabetes, respiratory disease, infections, and other causes” which suggests that cereal fibers, specifically, are particularly beneficial to our health.
Unfortunately, wholly whole products are rare on supermarket shelves. It only take a pinch of whole flour to darken a loaf, so, no matter what the package says, looking at labels is essential to determine how whole is a product.
In the end, the best way to eat whole bread is to bake your own with carefully selected ingredients. Here is a simple recipe for a fiber- and nutrient-rich whole bread: Almond-rye-raisin bread.
Consumption of whole grains and cereal fiber and total and cause-specific mortality: prospective analysis of 367,442 individuals, Huang et al., 2015, BioMed Central 2015, 13:59.
Spotlight on… low-GI, Jo Lewin, BBC Good Food.
Glycemic index and obesity, Brand Miller et al., American Journal of Clinical Nutrition, July 2002 vol. 76 no. 1 281S-285S.
Carbohydrates and Blood Sugar, Harvard School of Public Health.
Glycemic Index and Diabetes, American Diabetes Association.
Glycemic Index Defined, Glycemic Research Institute.
What is a whole grain?, The Whole Grains Council.
EFSA sets European dietary reference values for nutrient intakes, European Food Safety Authority, 26 March 2010.