How Bread Has Changed: Refined Flour, Fast Baking, Additives, and How to Choose a Better Loaf

For most of human history, bread was made from whole grains ground between stones, mixed with water and salt, and leavened slowly with wild yeasts and bacteria. Today, most bread in supermarkets is made from refined flour in industrial bakeries in a few hours, often with added sugar, oils, dough conditioners, and preservatives that keep it soft for weeks. Many people sense that bread is not what it used to be, and some blame modern wheat itself for digestive problems and rising rates of celiac disease.

Some changes to bread have harmed its nutritional value, others have improved public health, and some popular explanations do not hold up to scrutiny. This article reviews how bread has changed, what research shows about refined versus whole grain bread, additives, sodium, fermentation, and modern wheat, and how to choose a better loaf.

Why is modern bread different and is it less healthy? Industrial milling, faster baking, and additives transformed bread over the past century. Roller mills strip the nutritious bran and germ, so refined flour is enriched to add back some nutrients, including folic acid that prevents birth defects. Modern bread is often higher in sodium and additives and made with very fast fermentation. Whole-grain and slow-fermented breads are generally the healthier choices.

How Did Milling Change Bread?

Industrial roller mills, which replaced stone grinding, strip away the bran and germ to produce fine white flour with longer shelf life but fewer nutrients, which is why refined flour is enriched. Until the late 19th century, most flour was stone-ground, retaining at least part of the bran and germ, which contain fiber, vitamins, minerals, and healthy fats. White flour existed but was expensive and associated with wealth. Steel roller mills, introduced widely in the 1870s and 1880s, efficiently separated the starchy endosperm from bran and germ, producing fine white flour cheaply and in large volumes. Because the germ contains oils that can turn rancid, removing it also gave white flour a long shelf life. White bread became the standard, and with it came the loss of much of wheat’s fiber, magnesium, zinc, vitamin E, and B vitamins.

The nutritional consequences became visible. Deficiency diseases such as pellagra, caused by niacin deficiency, were common in parts of the United States in the early 20th century where diets relied heavily on refined grains. In the 1940s, the United States began enriching white flour with thiamin, riboflavin, niacin, and iron, which helped eliminate these deficiency diseases. Enrichment restores only some nutrients lost in refining, however; fiber, magnesium, vitamin E, and many phytochemicals are not replaced.

Why Is Folic Acid Added to Bread?

Since the late 1990s, folic acid has been added to enriched grain products because it sharply reduces neural tube birth defects, making fortified bread one of the clearest public-health successes in food. Not all modern changes to bread have been negative. Beginning in 1998, the United States required that enriched cereal grain products, including flour and bread, be fortified with folic acid to reduce birth defects of the brain and spine. A 2015 CDC report in Morbidity and Mortality Weekly Report by Jennifer Williams and colleagues analyzed data from 19 birth defects surveillance programs from 1999 to 2011 and estimated that fortification prevents approximately 1,326 neural tube defect-affected births each year. Folic acid fortification is one of the most successful public health interventions involving bread. Note that many whole grain and organic breads are not fortified, so people who could become pregnant should ensure adequate folic acid from other sources.

Faster Bread: Industrial Baking

Traditional bread making involved long fermentation, often overnight or longer, during which yeasts and bacteria develop flavor, partially break down starches and proteins, and leaven the dough. In 1961, British researchers developed the Chorleywood bread process, which uses intense mechanical mixing, extra yeast, and additives to produce dough ready to bake in a fraction of the time. Similar high-speed methods spread worldwide. These processes allowed large bakeries to produce soft, uniform, inexpensive loaves quickly, and they work well with lower-protein wheat. The trade-off is less fermentation time, and industrial loaves often rely on added ingredients to achieve the texture, shelf life, and flavor that time once provided.

What Additives Are in Modern Bread?

Industrial breads often contain dough conditioners, preservatives, emulsifiers, and added sugars to speed production and extend shelf life, ingredients absent from simple traditional bread. Supermarket bread ingredient lists can include dough conditioners such as DATEM, sodium stearoyl lactylate, and mono- and diglycerides, which strengthen dough and soften crumb; enzymes; preservatives such as calcium propionate; added sugars or high-fructose corn syrup; vegetable oils; vital wheat gluten; and in some products, oxidizing agents. Most of these are considered safe by regulators at the levels used. Two flour treatment agents have drawn particular scrutiny.

Potassium bromate strengthens dough and helps bread rise higher. A 1990 review in Environmental Health Perspectives by Yuji Kurokawa and colleagues in Japan reported that potassium bromate induced kidney tumors, peritoneal mesotheliomas, and thyroid tumors in rats and was nephrotoxic in humans and animals, though adverse effects were not evident in animals fed bread made from treated flour, since most bromate is converted during baking when used properly. The International Agency for Research on Cancer classifies it as possibly carcinogenic to humans. It is banned in the European Union, the United Kingdom, Canada, and many other countries, and California’s Food Safety Act bans it from food starting in 2027. In the rest of the United States it remains legal, though many bakers have stopped using it.

Azodicarbonamide is a flour bleaching agent and dough conditioner that drew attention in 2014 when a blogger noted it is also used in making foam products such as yoga mats. When bread is baked, it breaks down into compounds including semicarbazide, which has caused tumors in animals at high doses. It is not permitted in food in the European Union. Several major chains removed it from their bread after public pressure, though it remains legal in the United States.

Bread and Sodium

Bread is not especially salty per slice, but people eat a lot of it. A 2017 CDC analysis in Morbidity and Mortality Weekly Report by Zerleen Quader and colleagues found that in 2013–2014, 70 percent of dietary sodium in the United States came from 25 food categories, and breads were the top single contributor, accounting for 6 percent of sodium consumed. Sodium content varies widely between brands, so comparing labels can make a meaningful difference for people watching blood pressure. Some countries have successfully reduced salt in bread through voluntary or mandatory targets without consumers noticing a change in taste.

Is Modern Wheat the Reason Bread Causes Problems?

Claims that modern wheat is uniquely harmful are largely unsupported; wheat has changed through breeding, but there is little evidence it causes widespread harm in people without celiac disease or wheat allergy. A popular theory holds that modern wheat breeding increased gluten content, explaining rising rates of celiac disease and gluten sensitivity. A 2013 analysis in the Journal of Agricultural and Food Chemistry by Donald Kasarda of the USDA Agricultural Research Service reviewed U.S. data from the 20th and 21st centuries and found no evidence that wheat breeding had increased the protein content of wheat, which is proportional to gluten content. Kasarda instead pointed to possible roles for changes in per capita wheat flour consumption and the increasing use of vital wheat gluten as a food additive, which has risen substantially since the 1970s. Other researchers have examined whether specific gluten proteins or immune-triggering fragments differ between older and modern wheat varieties, with mixed results. Popular diet rules about what to eat together, such as food combining, have little support in digestion research.

Celiac disease, an autoimmune condition triggered by gluten, has become more common and better diagnosed in recent decades, for reasons that likely include genetics, infections, the gut microbiome, and timing of gluten introduction in infancy, not simply wheat composition. Non-celiac gluten or wheat sensitivity is less well understood; some people who feel better avoiding wheat may be reacting to fermentable carbohydrates called fructans rather than gluten. People with suspected celiac disease should be tested before eliminating gluten, since testing requires gluten in the diet.

Is Sourdough Healthier Than Regular Bread?

Slow fermentation, as in sourdough, can improve flavor, lower the glycemic response somewhat, and make some nutrients more available, so traditionally fermented breads may have modest advantages over fast-made bread. Long fermentation, as in traditional sourdough, changes bread in several ways. Lactic acid bacteria and wild yeasts acidify the dough, break down some phytic acid that binds minerals, partially break down gluten and fructans, and produce flavor compounds. Some studies have found lower blood sugar responses to sourdough than to conventional yeast bread. However, responses vary greatly between individuals. A 2017 randomized crossover trial in Cell Metabolism by Tal Korem and colleagues at the Weizmann Institute compared one week of traditionally made sourdough whole grain bread with one week of industrial white bread in 20 adults and found no significant differences between bread types in multiple clinical measures on average. However, individual glycemic responses differed markedly: some people had lower blood sugar responses to sourdough and others to white bread, and these responses could be predicted from their gut microbiome. The study suggests that the best bread for blood sugar may be personal, though whole grains offer benefits beyond glycemic response.

Whole Grain Bread and Health

Large observational studies consistently link whole grain consumption to better health. A 2016 meta-analysis in The BMJ by Dagfinn Aune and colleagues pooled 45 prospective studies and found that each additional 90 grams of whole grains per day, about two slices of whole grain bread and a bowl of whole grain cereal, was associated with a 19 percent lower risk of coronary heart disease, 22 percent lower risk of cardiovascular disease, 15 percent lower risk of cancer death, and 17 percent lower risk of death from all causes. Whole grain bread provides fiber that supports digestive health and satiety, and whole grains are associated with lower risk of type 2 diabetes. Choosing truly whole grain bread is one of the simplest ways to restore what was lost when flour became refined.

Bread as an Ultra-Processed Food

Under the NOVA classification used in much nutrition research, mass-produced packaged breads containing additives such as emulsifiers and preservatives are considered ultra-processed foods, while breads made from flour, water, salt, and yeast or sourdough starter are considered processed foods. A 2019 inpatient randomized trial in Cell Metabolism by Kevin Hall and colleagues at the National Institutes of Health found that adults offered an ultra-processed diet ate about 500 more calories per day and gained weight, compared with when they were offered an unprocessed diet matched for presented calories, sugar, fat, fiber, and sodium. The trial did not isolate bread, and not all ultra-processed foods are equally unhealthy; whole grain packaged breads may differ from white sandwich bread. Still, the findings support choosing breads with simpler ingredient lists when possible.

How to Read a Bread Label

Choosing a Better Loaf

Look for 100 percent whole grain. The first ingredient should be whole wheat flour or another whole grain. Color is not a reliable guide.

Check fiber. At least 3 grams of fiber per slice is a useful benchmark for whole grain bread.

Compare sodium and added sugars. Choose breads lower in sodium and with little or no added sugar.

Prefer shorter ingredient lists. Breads from flour, water, salt, and yeast or starter are less processed than those with long lists of conditioners and preservatives.

Avoid potassium bromate. Check labels for potassium bromate or “bromated flour” if you live where it remains legal.

Consider real sourdough. Traditional sourdough bakeries list only flour, water, salt, and starter.

Consider organic whole grains. Organic bread reduces exposure to herbicide residues such as glyphosate, as explained in our article on glyphosate in whole grain bread.

Making Bread at Home

Home baking offers full control over ingredients. A basic whole grain loaf needs only whole wheat flour, water, salt, and yeast, and many home bakers use long, slow fermentation, such as no-knead methods with overnight rises, to develop flavor without additives. Sourdough requires maintaining a starter but rewards bakers with complex flavor and traditional fermentation. Mixing whole wheat with some bread flour can improve texture for beginners. Adding seeds, oats, or other whole grains boosts fiber. Home-baked bread without preservatives stales faster, so slicing and freezing part of a loaf keeps it fresh.

Ancient Grains and Heritage Wheat

Interest in older wheat varieties such as einkorn, emmer, spelt, and heritage wheats has grown, with some people reporting better tolerance. These grains differ in protein composition and flavor, and some contain different gluten proteins than modern bread wheat, but they still contain gluten and are not safe for people with celiac disease. Research comparing their effects on digestive symptoms is limited. Ancient grains can add variety and flavor, and whole grain versions provide fiber and nutrients similar to whole wheat.

Bread Around the World

Bread traditions vary widely. In Germany and Scandinavia, dense rye breads with long fermentation are common and naturally high in fiber. In France, traditional baguettes are protected by a 1993 decree limiting ingredients to flour, water, salt, and leavening for the “pain de tradition française.” In the Middle East and South Asia, flatbreads made with whole wheat are staples. These traditions show that bread can be simple and nourishing, and many countries regulate additives more strictly than the United States.

Gluten-Free Bread Is Not Automatically Healthier

Gluten-free breads are essential for people with celiac disease, but they are not healthier for everyone. Many are made from refined starches such as rice flour, tapioca, and potato starch, with added gums, sugars, and fats to mimic the texture of wheat bread. They are often lower in fiber and protein and are frequently not enriched or fortified. People without celiac disease or diagnosed sensitivity who switch to gluten-free bread may lose fiber and B vitamins. Gluten-free breads made with whole grains such as brown rice, sorghum, buckwheat, or certified gluten-free oats are better choices for those who need them.

Bread and Body Weight

Bread is often blamed for weight gain, but research distinguishes between types. Refined white bread is easy to overeat, digests quickly, and is associated with weight gain in some observational studies, while whole grain bread is associated with lower weight gain over time. Portion size and what goes on the bread, such as butter, processed meats, or sugary spreads, matter as much as the bread itself. Replacing refined bread with whole grain versions and pairing it with protein and vegetables supports satiety and weight management.

Preservatives and Shelf Life

Commercial bread stays soft for days or weeks thanks to preservatives such as calcium propionate, sorbic acid, and cultured wheat, along with enzymes and emulsifiers that slow staling. These additives reduce food waste and are considered safe at approved levels, though some people prefer to avoid them. Breads without preservatives, such as bakery and homemade loaves, mold or stale faster and are best stored at room temperature for a day or two or frozen for longer storage. Refrigeration speeds staling of bread and is generally not recommended except in very humid climates.

A Balanced View

Bread has changed in ways that reduced its nutritional value, especially the shift to refined flour and fast industrial methods, and some additives used in the United States are banned elsewhere. Yet enrichment and folic acid fortification have prevented deficiency diseases and birth defects, and the claim that modern wheat breeding has dramatically increased gluten is not supported by U.S. data. The practical message is not to fear bread but to choose it carefully: whole grain, simply made, lower in sodium and sugar, and free of controversial additives.

Practical Takeaways

Choose bread with a whole grain as the first ingredient and at least 3 grams of fiber per slice. Compare sodium between brands. Avoid potassium bromate and minimize breads with long additive lists. Try traditional sourdough, sprouted grain, or rye bread for variety. If you avoid gluten for medical reasons, choose whole grain gluten-free options. Consider organic whole grain bread to reduce pesticide residues. If you bake at home, use whole grains and long fermentation for flavor without additives.

Bread and Digestive Comfort

Some people experience bloating or discomfort after eating bread. Possible causes include celiac disease, wheat allergy, sensitivity to fructans or other fermentable carbohydrates, and simply eating large portions. For people with irritable bowel syndrome, traditional sourdough made with long fermentation may be better tolerated because fermentation reduces fructans, though results vary. Keeping a food and symptom diary and working with a clinician or registered dietitian can help identify triggers. Eliminating all wheat without testing can mask celiac disease and lead to unnecessary dietary restriction.

Sprouted Grain and Rye Breads

Sprouted grain breads are made from whole grains allowed to germinate before being ground or mashed. Sprouting activates enzymes that partially break down starches and phytic acid, and some studies suggest modest improvements in mineral availability and blood sugar response, though evidence is limited. Rye breads, especially traditional dense whole rye loaves common in Northern Europe, are high in fiber and have been associated in some studies with lower insulin responses than wheat bread. Both are good options for variety, provided they are made mostly from whole grains rather than refined flour with a small amount of sprouted or rye flour added.

Questions to Ask Your Local Bakery

Bakeries can tell you more than a label. Ask what flour they use and whether it is whole grain or organic, how long the dough ferments, whether they use dough conditioners or preservatives, and how much salt goes into each loaf. Many small bakeries take pride in simple ingredients and long fermentation and are happy to explain their methods.

Why Bread Still Matters

Bread remains a staple for billions of people and a major source of energy, B vitamins, iron, and, when made from whole grains, fiber. In the United States, grain products contribute substantially to intake of folate and iron, particularly for women of childbearing age, because of enrichment and fortification. Rather than eliminating bread, improving its quality offers one of the easiest ways to raise fiber intake, which most Americans fall far short of. Small shifts, such as switching from white to whole grain sandwich bread, add up over a lifetime.

Policy can help too. Public health experts have proposed incentives for whole grain products in school meals, sodium reduction targets for bakeries, and stricter review of older additives. Consumers’ choices at the store also signal demand for better bread, encouraging manufacturers and bakeries to offer more whole grain, lower-sodium, and simply made loaves at affordable prices across the country.

Storing Bread Well

Keep bread at room temperature in a bread box or paper bag for a day or two, and freeze sliced bread for longer storage, toasting slices straight from the freezer. Discard bread with visible mold, since mold can spread unseen through soft bread.

Common Myths

“Modern wheat has much more gluten.” U.S. data do not show increased wheat protein or gluten from breeding; added vital gluten has increased.

“All bread is unhealthy.” Whole grain bread is linked to lower risks of heart disease, cancer death, and overall mortality.

“Brown bread is whole grain.” Color can come from molasses or caramel; check the ingredient list.

“Sourdough is safe for celiac disease.” Regular sourdough contains gluten and is not safe for people with celiac disease.

“Enriched bread is as nutritious as whole grain.” Enrichment restores some vitamins and iron but not fiber and many other nutrients.

Key Terms

Endosperm: The starchy inner part of a grain kernel, the main component of white flour.

Bran and germ: The outer layers and embryo of the grain, rich in fiber, vitamins, and minerals.

Enrichment: Adding back certain vitamins and iron to refined flour.

Dough conditioner: An additive that strengthens or softens dough.

Fructans: Fermentable carbohydrates in wheat that can cause digestive symptoms in some people.

The Bottom Line

Bread has changed dramatically over the past 150 years. Roller milling made refined white flour the norm, industrial baking shortened fermentation and added conditioners and preservatives, and bread became a leading source of sodium. Some changes helped public health, including enrichment and folic acid fortification, while some U.S. additives such as potassium bromate are banned in many other countries. Evidence does not support the idea that modern wheat breeding increased gluten content. Whole grain bread is linked to lower risks of heart disease and early death, so the best response to modern bread is to choose whole grain, simply made loaves lower in sodium and sugar, or to bake your own.

Frequently Asked Questions

Why is modern bread different from bread in the past?

Modern bread differs mainly because of industrial milling, faster baking, and additives. Roller mills strip the nutritious bran and germ to make fine white flour, which is then enriched to replace some lost nutrients. Industrial baking uses very fast fermentation and dough conditioners, preservatives, and added sugars. The result is bread that is cheaper and longer-lasting but often more processed than traditional loaves.

Is white bread bad for you?

White bread is not inherently harmful, but it is less nutritious than whole-grain bread because refining removes fiber, vitamins, and minerals from the bran and germ. Enrichment adds back some nutrients, including folic acid, but not the fiber. Whole-grain breads are generally a healthier choice, while white bread is fine in moderation as part of a balanced diet.

Why is folic acid added to bread and flour?

Folic acid has been added to enriched grain products in the United States since the late 1990s because it dramatically reduces the risk of neural tube birth defects like spina bifida when consumed by women before and during early pregnancy. This fortification is considered a major public-health success, preventing thousands of serious birth defects, which is why it remains standard in bread and flour.

Is modern wheat causing gluten problems?

For people without celiac disease or a wheat allergy, there is little scientific evidence that modern wheat is uniquely harmful. Wheat has changed through breeding, but claims that it is the cause of widespread modern illness are largely unsupported. Some people report sensitivity to wheat or to fast-fermented bread, and research into non-celiac wheat sensitivity continues, but modern wheat is not broadly toxic.

Is sourdough or slow-fermented bread healthier?

Traditionally fermented breads like sourdough may have modest advantages. The long fermentation can lower the glycemic response somewhat, improve flavor, and make certain minerals more available by breaking down compounds that block their absorption. Some people also find slow-fermented bread easier to digest. While not a cure-all, choosing whole-grain, slowly fermented bread is generally a healthier option than fast-made industrial bread.

References

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2. Kurokawa Y, Maekawa A, Takahashi M, Hayashi Y. Toxicity and carcinogenicity of potassium bromate—a new renal carcinogen. Environmental Health Perspectives. 1990;87:309–335. PMID 2269236
3. Quader ZS, Zhao L, Gillespie C, et al. Sodium Intake Among Persons Aged ≥2 Years – United States, 2013–2014. MMWR Morbidity and Mortality Weekly Report. 2017;66(12):324–328. PMID 28358799
4. Kasarda DD. Can an increase in celiac disease be attributed to an increase in the gluten content of wheat as a consequence of wheat breeding? Journal of Agricultural and Food Chemistry. 2013;61(6):1155–1159. PMID 23311690
5. Korem T, Zeevi D, Zmora N, et al. Bread Affects Clinical Parameters and Induces Gut Microbiome-Associated Personal Glycemic Responses. Cell Metabolism. 2017;25(6):1243–1253.e5. PMID 28591632
6. Aune D, Keum N, Giovannucci E, et al. Whole grain consumption and risk of cardiovascular disease, cancer, and all cause and cause specific mortality: systematic review and dose-response meta-analysis of prospective studies. BMJ. 2016;353:i2716. PMID 27301975
7. Hall KD, Ayuketah A, Brychta R, et al. Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake. Cell Metabolism. 2019;30(1):67–77.e3. PMID 31105044

Last updated: October 6, 2026