Bread is not proven to be an inflammatory food. In trials, swapping refined grains for whole grains led to small drops in CRP, a blood marker of inflammation, or to no change. White bread is only linked to higher CRP in observational data. Sourdough has no clear edge for inflammation.
Why bread gets blamed
The idea makes some sense on the surface. White bread is made from refined flour, and refined grain shows up again and again on "foods to avoid" lists. There is one real data point behind the worry. In a study of 756 generally healthy adults aged 53 to 73, each extra 50 grams a day of refined grain went with 0.23 mg/L higher hs-CRP.
CRP (C-reactive protein) is a protein in your blood that rises when there is inflammation in the body. The "hs" means a sensitive test that can pick up low levels.
But that study only watched what people ate. It did not change anyone's diet, so it shows a link, not proof. The same study found the opposite for whole grain: each extra 50 grams a day went with 0.12 mg/L lower hs-CRP. And when the researchers accounted for the fiber in grains, the links got weaker, which hints that fiber explains part of the story.
So the real question isn't "bread or no bread." It's what kind of grain.
Does whole wheat bread reduce inflammation?
Here the trials get interesting, because they actually changed what people ate.
In 12 of 31 trials, whole grain foods lowered at least one inflammation marker.From a 2022 systematic review in Nutrients
A 2020 meta-analysis pooled the trials that compared whole grains with refined grains. A meta-analysis combines the results of many studies into one answer. It included 25 randomized trials, running from 2 to 16 weeks, and found that whole grains improved CRP. An earlier 2019 meta-analysis of 13 trials with 466 people found the same for hs-CRP and for IL-6, another inflammation signal.
That sounds like a win. Then you look closer.
A third meta-analysis, also from 2020, pooled 14 trials with 1,238 adults. It found no clear effect of whole grains on CRP, IL-6 or TNF-alpha overall. The benefit only showed up in some groups: people whose CRP was already high, and trials where both diets had the same calories. The authors said the studies were too different from each other to draw firm conclusions.
A 2022 review counted results instead of pooling them. Of 31 trials, 12 found that whole grain foods lowered at least one inflammation marker. CRP fell in 10 of 32 studies that measured it, and IL-6 fell in just 2 of 18.
What the trials looked like up close
Two trials show why the answers differ.
In Denmark, 60 adults at risk of metabolic syndrome ate a whole grain diet for 8 weeks and a refined grain diet for 8 weeks, in random order. The 50 who finished ate about 179 grams of whole grain a day on the whole grain diet, against 13 grams on the refined one. On whole grain, their CRP and IL-6 dropped. They also lost weight, and that fit with eating fewer calories. The drop in IL-6 was tied most to how much rye they ate.
In a U.S. trial, 81 healthy adults aged 40 to 65 ate whole or refined grains for 6 weeks on diets designed to keep their weight steady. Whole grain did help their digestion, with heavier and more frequent stools. But it had no effect on inflammation in the body or the gut.
Put those side by side. In people at higher risk who also lost weight, inflammation markers fell. In healthy people whose weight was held steady, they didn't move.
Is sourdough bread inflammatory?
Sourdough is bread raised by a live culture of bacteria and yeast instead of baker's yeast alone. It has a reputation as the gentle, gut-friendly loaf.
The research is thinner than the reputation. A 2023 review gathered 25 trials with 542 people that compared sourdough with yeast bread. Most measured blood sugar after eating. Only 2 looked at heart health markers. The authors said it is hard to reach a clear answer on sourdough's health benefits, because the bacteria, the flour and the fermenting method all vary from loaf to loaf. Some sourdoughs made with specific bacteria and methods did improve blood sugar response, fullness or gut comfort.
In a 2017 trial, people ate traditional whole grain sourdough for a week and industrial white bread for another week. Across many health measures, the bread type made no clear difference. Blood sugar responses varied a lot from person to person.
And longer rising doesn't seem to add much. In a 2024 trial of 31 adults with metabolic syndrome, a sourdough rested for 48 hours did no better than one rested for 2 hours over two months. The short-rise loaf lowered a few inflammation markers more. That trial had no regular bread group, so it can't tell us whether sourdough beats other bread.
Does bread cause inflammation in joints?
No trial in our evidence tested bread and joint pain. One long study did look at knees. It followed 2,846 adults aged 45 to 79 for 96 months. People who ate the most whole grain had a lower risk of knee osteoarthritis than those who ate the least, and the same held for dark bread. This is a link, not proof, and it points away from bread as a joint trigger.
What this means for you
Tick what you'll try this week. Your picks stay on this device.
you have celiac disease or think wheat makes you sick, since that needs testing rather than guesswork; you have diabetes and take medicine that lowers blood sugar, because changing your carbs can change your readings; or you have a high CRP result you want explained.
One tap. Results appear once 50 readers have voted, and the count is always real.
The bottom line
The case against bread comes from one kind of study that watched people's plates. The trials that changed those plates told a quieter story. Swap white bread for whole grain and CRP might dip a little, or might not move at all. Choose sourdough and the evidence shrugs. Bread is not an inflammatory food. The grain it's made from matters more than the loaf, so make your next one whole grain.
Common questions
Does bread cause inflammation in the body?
There is no trial evidence that it does. In trials, swapping refined grains for whole grains gave small drops in CRP or no change. Only observational data link refined grains to higher CRP: in 756 adults, each extra 50 grams a day of refined grain went with 0.23 mg/L higher hs-CRP. That shows a link, not proof.
Is sourdough bread inflammatory?
Not as far as the research shows, but it isn't proven to calm inflammation either. A 2023 review of 25 trials could not find a clear health edge for sourdough over other bread. In a 2024 trial, a 48-hour sourdough did no better than a 2-hour one in adults with metabolic syndrome. Pick it if you like the taste.
Does whole wheat bread reduce inflammation?
Maybe a little. A 2020 meta-analysis of 25 trials found that whole grains, eaten instead of refined grains, improved CRP. But another meta-analysis of 14 trials found no clear effect overall, with benefits only in people whose CRP was already high. Whole grains helped most often in people with overweight or a health condition.
Does bread cause inflammation in joints?
No trial in our evidence tested it. A study of 2,846 adults followed for 96 months found that people who ate the most whole grain had a lower risk of knee osteoarthritis, and dark bread showed the same link. It does not prove whole grain protects knees, but it gives no sign that bread harms them.
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How this article was made
Researched and written from 11 peer-reviewed papers. Our automated check matched every claim against the exact words of its source, confirmed every paper exists in PubMed, and found none retracted. Checked November 1, 2026. Not individually reviewed by a doctor. Photos are illustrative; the people in them are not patients or readers.
Grades run Strong, Moderate, Emerging, Early and Not supported, and the grade decides the words we may use. How we grade evidence · Medical disclaimer
Sources
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- Meta-analysisEffects of Whole-Grain Consumption on Selected Biomarkers of Systematic Inflammation: A Systematic Review and Meta-analysis of Randomized Controlled Trials.Hajihashemi P, Haghighatdoost F J Am Coll Nutr, 2019.PubMedFull paper
- Meta-analysisThe Effect of Replacing Refined Grains with Whole Grains on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials with GRADE Clinical Recommendation.Marshall S, Petocz P, Duve E et al. J Acad Nutr Diet, 2020.PubMedFull paper
- Systematic reviewWhole Grain Consumption and Inflammatory Markers: A Systematic Literature Review of Randomized Control Trials.Milesi G, Rangan A, Grafenauer S Nutrients, 2022.PubMedFull paper
- Randomized trialWhole grain-rich diet reduces body weight and systemic low-grade inflammation without inducing major changes of the gut microbiome: a randomised cross-over trial.Roager HM, Vogt JK, Kristensen M et al. Gut, 2019.PubMedFull paper
- Randomized trialSubstituting whole grains for refined grains in a 6-wk randomized trial has a modest effect on gut microbiota and immune and inflammatory markers of healthy adults.Vanegas SM, Meydani M, Barnett JB et al. Am J Clin Nutr, 2017.PubMedFull paper
- ObservationalThe associations between whole grain and refined grain intakes and serum C-reactive protein.Taskinen RE, Hantunen S, Tuomainen TP et al. Eur J Clin Nutr, 2022.PubMedFull paper
- Systematic reviewNutritional benefits of sourdoughs: A systematic review.Ribet L, Dessalles R, Lesens C et al. Adv Nutr, 2023.PubMedFull paper
- Randomized trialBread Affects Clinical Parameters and Induces Gut Microbiome-Associated Personal Glycemic Responses.Korem T, Zeevi D, Zmora N et al. Cell Metab, 2017.PubMedFull paper
- Randomized trialSourdough Bread with Different Fermentation Times: A Randomized Clinical Trial in Subjects with Metabolic Syndrome.Pérez-Vega KA, Sanllorente A, Zomeño MD et al. Nutrients, 2024.PubMedFull paper
- CohortWhole grain consumption and risk of radiographic knee osteoarthritis: a prospective study from the Osteoarthritis Initiative.Liu T, Xu C, Driban JB et al. Rheumatology (Oxford), 2023.PubMedFull paper
