Important Points:
- whole grains
- refined grains
- Western dietary pattern
- diabetes
- obesity
Refined Grains: The Good, the Bad, the Ugly
Refined grains are grains stripped of their bran and germ, such as white flour and white rice. Refining removes about a quarter of the protein. It also removes half or more of many nutrients, and enrichment puts back only a fraction. Two slices of wheat bread raise blood sugar higher than six teaspoons of table sugar.
Flour is all around us. It tempts us at every meal. Breakfast means toast, bagels, cereal and pancakes. Lunch means sandwiches, wraps, pasta and pizza. Refined grains have been blamed as one of the leading causes of poor health. Is that true? Should we toss all refined grain products off our tables? Here we take a close look at the good, the bad and the ugly of refined flour, so you know what is on your plate.
What are Refined Grains?
A refined grain is not whole because it is missing one or more of its three key parts: the bran, the germ or the endosperm. White flour and white rice are refined grains, for instance, because both have lost their bran and germ. Only the endosperm is left. Refining strips out about a quarter of a grain’s protein. It also strips out half to two thirds or more of a score of nutrients. What is left is a mere shadow of the original grain.
More refining steps include mixing, bleaching and brominating. Makers also often add thiamin, riboflavin, niacin and iron back in to enrich the product. Because the added nutrients are only a fraction of what was removed, refined grains are considered nutritionally worse than whole grains. Still, for some grains, losing the fiber and grinding fine makes slightly more of the grain’s energy available to the body.
Grain refining led to disastrous and widespread health problems. Among them were the deficiency diseases pellagra and beri-beri. In response, many governments recommended or required that refined grains be “enriched.”
The Good: do refined grains have any benefits?
The federal government’s 2010 Dietary Guidelines for Americans give advice on grains. They say half of your daily grains should come from whole grains high in fiber, such as brown rice, oatmeal and whole-wheat bread. We do not follow that advice. We recommend no refined grains for our patients, and we do not build meals around grains.
One nutrition researcher, Julie Miller Jones, a professor emeritus at St. Catherine University, argues that refined grains have one benefit: the nutrients added back to refined flours. That does not make white flour a good food. It makes it a processed food with a patch.
Folic acid was added to bread, cereal and other grains in 1999. Since then, the rate of newborns with neural tube defects has dropped 46%. These defects are a known result of folic acid deficiency. Leafy greens supply folate without the blood sugar spike, and women planning a pregnancy should take a folic acid supplement rather than rely on white bread for it. In chronic pain, gluten and gliadin in wheat drive a leaky gut and autoimmune trouble, and no added vitamin fixes that.
The Bad: why is white flour bad for you?
As our national appetite for flour has inched up, so have diet-related ills such as obesity, heart disease and diabetes. Coincidence? Many nutrition experts don’t think so. When they weigh the evidence linking food choices and disease, they see the white, dusty fingerprints of flour everywhere.
Flour started out as a clever fix to a hard problem. Grass seeds were plentiful. But the tough outer shell (the husk) made the seeds hard to chew and digest. Early humans outsmarted the seeds by grinding them between stones. That crushed the outer layers to get at the goodness inside. The result, a coarse powder, was the first whole-grain flour.
The downside was spoilage. Crushing the germ released its oils, and those oils quickly turned rancid in the air. Then industrial milling arrived in the late 1800s. Machines began filtering out the germ. They ground the remaining endosperm into a fine, white powder that lasted on the shelf for months. And so all-purpose white flour was born, along with a host of health problems.
Whole-kernel grains have a rigid structure. Inside it, they hide an array of vitamins, minerals, phytonutrients and fiber. But when machines grind kernels into flour, even whole-grain flour, what is left is a starchy powder. That powder can wreak havoc on the body.
The Ugly
Eating too much flour can lead to a number of problems in the body, including:
- Food Allergies/Intolerances. Gluten intolerance has become a term tied to this generation. Wheat is one of the biggest food triggers of allergies and intolerances. The exact reason is unclear. Still, many experts blame the higher gluten content of modern wheat.
- Blood-Sugar Spikes. The difference between a whole-kernel grain and a processed grain all comes down to the glycemic index. That index measures how fast the body turns food into fuel, or glucose. Foods made with wheat flour are especially damaging. Wheat has a carbohydrate called amylopectin A. It turns into blood sugar more easily than just about any other carbohydrate. Two slices of bread made with whole-wheat flour raise blood sugar higher than six teaspoons of table sugar. They also raise it higher than many candy bars.
- Food Cravings. One of the biggest changes in modern wheat is a modified form of gliadin. Gliadin is a protein found in wheat gluten. It gives the brain a feel-good effect by changing into a substance that crosses the blood-brain barrier and binds to the brain’s opiate receptors. That makes you want to eat more.
- Caloric Overload. A refined grain packs more calories than a whole-kernel grain because it is more concentrated. Foods high in grains also tend to be high in sugar and industrial fats. These foods add a great deal to obesity and the diabetes epidemic.
- Metabolic Slowdown. Research shows that high-glycemic-index foods may push the body to store nutrients as fat instead of burning them in muscle. In 2004, Ludwig and his colleagues at Harvard ran a study, published in the journal Lancet. They fed rats diets with the same nutrients, except for the type of starch. By the end, rats in both groups weighed roughly the same. But the rats on the high-glycemic diet had 71 percent more fat than the low-glycemic-index group.
- Inflammation. A diet high in grains stokes inflammation. When blood sugar spikes, glucose builds up in the blood significantly. Glucose drifting in the blood sticks to nearby proteins. This chemical reaction is called glycation. It is a pro-inflammatory process that plays a role in a host of inflammatory diseases.
- GI Disorders. Studies show that the lectins in grains inflame the lining of the gut and open cracks between cells. Also, when whole-kernel grains are refined, 80 percent of the fiber is lost, and gut health suffers. Fiber also helps sweep debris out of the gut. It supports the body’s vital elimination and detox processes. Those processes also help keep high cholesterol and inflammation at bay.
- Acid-Alkaline Imbalance. The body has a detailed system of checks and balances to hold its pH at a steady 7.4. A diet high in acidic foods, such as grains, forces the body to pull calcium from the bones to stay balanced. Researchers looked at how the diets of more than 500 women affected their bone density. A diet high in refined grains, among other nutrient-poor foods, was linked to bone loss. A highly acidic diet also chips away at our cell health and immunity. That can leave us open to chronic disease. Grains are the only plant foods that make acidic byproducts. Wheat, in particular, is among the most potent sources of sulfuric acid. This powerful substance quickly overpowers the neutralizing effect of alkaline bases.
The Bottom Line….
Grains are not essential, and there is no nutrient in there that you can’t get from other foods.
Related reading
Sources
- Swaminathan S, Dehghan M, Raj JM, et al. Associations of cereal grains intake with cardiovascular disease and mortality across 21 countries in Prospective Urban and Rural Epidemiology study: prospective cohort study. BMJ. 2021. PMID 33536317
- Schwingshackl L, Hoffmann G, Lampousi AM, et al. Food groups and risk of type 2 diabetes mellitus: a systematic review and meta-analysis of prospective studies. European Journal of Epidemiology. 2017. PMID 28397016
Medically reviewed by Dr. Gurpreet Singh Padda, MD, MBA, MHP
Interventional pain physician, addiction medicine specialist and obesity medicine diplomate.
Licensed in Missouri and Illinois.
Last reviewed June 18, 2026
