Refined grain consumption is not harmless, and we do not recommend any refined grains for our patients. A 2019 review from Arizona State University claimed that white bread, white rice and pasta are not linked to diabetes, heart disease or early death. That review was paid for in part by the grain industry, it lumped healthy people together with sick ones, and its own data show refined grains drive up blood sugar and insulin after every meal. Gluten grains also carry gliadin, a protein that opens the gut wall and feeds the autoimmune problems we see in chronic pain.
You may have seen the headline: “Refined grains are not the bad guy.” It spread fast because it told people what they wanted to hear. Here is what the review actually was, what it left out, and why our advice does not change.
What the review was, and who paid for it
The paper is a Perspective, an opinion article, published in Advances in Nutrition in 2019 by Professor Glenn Gaesser, Ph.D., of Arizona State University. It was not a new study. It reread 11 earlier reviews that covered 32 publications from 24 groups of people.
The paper’s own notes say it was paid for in part by a grant from the Wheat Foods Council and the Grain Foods Foundation. The author also sits on the scientific advisory boards of the Grain Foods Foundation, the Wheat Foods Council and Ardent Mills, a flour milling company. A review funded by the people who sell flour, concluding that flour is fine, is not the last word on flour.
What the review admits about blood sugar and insulin
Read past the headline and the review makes our case for us. It reports that, in controlled feeding trials, refined grains produced higher blood sugar and higher insulin after meals than whole grains did. The peak insulin response was much higher with refined grains.
It also states that high blood sugar after meals predicts heart disease better than a fasting blood sugar test does. That is the core of our approach. Our patients are already insulin resistant. A food that pushes blood sugar and insulin up after every meal is a food that keeps them sick, whatever a population average says.
What else the review conceded
- Refined grain intake was tied to a 27 percent higher risk of colon cancer in one of the meta-analyses it cites.
- White rice was tied to a higher risk of type 2 diabetes in populations that eat a lot of it.
- Most of the studies it relied on could not separate bread and pasta from cookies, cakes and donuts, so the author himself says the findings are hard to interpret.
- The author calls the gap between his conclusion and the large observational studies “a dilemma that needs resolution.” That is not a clean bill of health.
Why population averages do not fit our patients
The studies in that review tracked general populations, mostly people without diabetes or prediabetes. Our patients are different. They come to us with prediabetes, type 2 diabetes, belly fat, fatty liver and chronic pain driven by a body that is already metabolically sick.
Averages across millions of mostly healthy people can hide real harm in the people who can least afford it. When someone is insulin resistant, the insulin spike from white bread, white rice or pasta lands on a system that is already failing. In our population, refined grains are unhealthy, and they belong off the plate.
Gluten, gliadin and a leaky gut
Blood sugar is only part of the problem. Wheat and the other gluten grains carry a protein called gliadin. In the gut, gliadin binds a receptor on the lining (CXCR3). That triggers the release of zonulin, a signal that loosens the tight seals between gut cells. The gut wall becomes more permeable, often called a leaky gut.
This is not limited to people with celiac disease. In a 2015 study, gut tissue from every group tested, including people without celiac disease, became more permeable after gliadin exposure.
When the gut wall leaks, food proteins and bacterial fragments reach the immune system. In our chronic pain patients, we see autoimmune and inflammatory problems far more often than expected, and a leaky gut is a common thread. Gluten keeps that cycle going. That is one more reason we recommend no refined grains, and why removing gluten is part of how we treat chronic pain.
The larger study that found the opposite
Two years after the Arizona State review, the Prospective Urban and Rural Epidemiology (PURE) study was published in The BMJ. It followed 137,130 people in 21 countries for a median of 9.5 years.
People who ate the most refined grains, about 350 grams or 7 servings a day, had a 27 percent higher risk of death and a 33 percent higher risk of major heart and blood vessel disease than people who ate the least. Higher refined grain intake also went with higher blood pressure. The authors concluded that lower consumption of refined grains should be considered worldwide.
“But enriched grains add vitamins and fiber”
The review argues that cutting refined grains could leave people short of fiber and folic acid. Enriched flour has some vitamins added back after milling strips them out. That does not make it a good food. It makes it a processed food with a patch.
Vegetables supply fiber without the blood sugar spike. Leafy greens supply folate. Women who are planning a pregnancy should take a folic acid supplement, which is standard advice, rather than rely on white bread for it.
The review also blames red meat. We do not.
The review argues that red and processed meat, not refined grains, explain the poor health of people who eat a Western diet. We disagree. For our patients, red meat and fish are good protein. They keep blood sugar steady and help protect muscle. The foods that drive our patients’ disease are refined grains, added sugar and processed seed oils.
What we tell our patients to eat instead
- Build each meal around protein: red meat, fish and eggs.
- Fill the rest of the plate with vegetables.
- Cook with real olive oil.
- Leave refined grains off the plate: white bread, white rice, regular pasta, crackers and most breakfast cereals.
- Leave out added sugar and seed oils.
If you are trying to reverse prediabetes or type 2 diabetes, this is where we start. The details depend on your labs, your medications and your goals, which is why we build the plan with you.
Related reading
- Diet to Prevent Type 2 Diabetes
- The Problem With Refined Grains
- What’s on Your Plate: Refined Grains vs. Whole Grains
References
- Gaesser GA (2019). Perspective: Refined Grains and Health: Genuine Risk, or Guilt by Association? Advances in Nutrition 10(3):361-371. Funding and author disclosures are listed in the article notes. https://doi.org/10.1093/advances/nmy104
- Swaminathan S, et al. (2021). Associations of cereal grains intake with cardiovascular disease and mortality across 21 countries in Prospective Urban and Rural Epidemiology study: prospective cohort study. BMJ 372:m4948. https://doi.org/10.1136/bmj.m4948
- Lammers KM, et al. (2008). Gliadin induces an increase in intestinal permeability and zonulin release by binding to the chemokine receptor CXCR3. Gastroenterology 135(1):194-204. https://doi.org/10.1053/j.gastro.2008.03.023
- Hollon J, et al. (2015). Effect of gliadin on permeability of intestinal biopsy explants from celiac disease patients and patients with non-celiac gluten sensitivity. Nutrients 7(3):1565-1576. https://doi.org/10.3390/nu7031565
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 October 4, 2026
