Bread wheat is a young hybrid with three genomes. About 8,500 to 9,000 years ago a farmed wheat with two sets of chromosomes crossed with a wild grass, Aegilops tauschii, and the result carried three sets, called A, B and D. Its reference genome holds 107,891 high-confidence genes. Wheat also grows on more land than any other food crop, 219.5 million hectares in 2024, and it yielded about 799 million tonnes.
The wheat on this page is the whole kernel, also called a wheat berry, in the USDA entry for hard white wheat. A quarter cup (48 g) of dry kernels has 164 calories, 5.9 g of fiber and 5.4 g of protein, and it gives 80% of the daily value for manganese. Per 100 g it has 12.2 g of fiber, which ranks ninth of 109 foods for fiber on this site. White flour keeps mostly the starchy center: in a review of wheat composition, total fiber averaged 13.4 g per 100 g of dry whole-grain flour against 3.5 g in white flour.
Around 80% of the protein in the starchy center of the kernel is gluten proteins, which give dough its stretch. Gluten is also why wheat is a major food allergen and why celiac disease matters: about 1.4% of people worldwide test positive for it, and about 1 in 10 say they are sensitive to gluten or wheat. The studies below test what whole wheat does for the bowel, heart and blood sugar, what trials say about gluten, and the claims of the book Wheat Belly. Many whole-grain studies pool wheat with other grains, and each card says so.
Health benefits of wheat
The top findings from 31 studies, strongest evidence first
What the stars mean
- Strong. Several randomized trials, pooled in a meta-analysis, point the same way, or regulators (FDA or EFSA) have approved the claim.
- Moderate. Good randomized trials support it, but there are fewer of them, or their results vary.
- Limited. Small, short or single trials, or mixed results. Promising, but it needs confirmation.
Population and lab studies get no stars: they show a link or a mechanism, not proof.
How we rate evidence →- ★★★More stool bulk from wheat fiberAcross 65 trials, each extra gram of wheat fiber a day added about 3.7 g to daily stool weight. The EU lets foods high in wheat bran fiber claim this.
- ★★Lower blood pressure in one trialWhole-grain wheat foods for 12 weeks lowered the top number by 6 mm Hg (systolic) in 233 middle-aged adults at higher heart risk.
- ★★Did not stop polyps coming backTaking 13.5 g a day of wheat bran fiber for about three years did not prevent colorectal adenomas (polyps) from returning. New ones appeared in 47.0% on high fiber and 51.2% on low.
- ★★Whole grains: no clear change in cholesterolIn 316 overweight adults, 60 g or 120 g a day of mixed whole-grain foods (not wheat alone) changed none of the heart-risk markers measured. A Cochrane review of whole grains found no clear change in total cholesterol.
- ★★No change in body weightAcross 26 trials, whole grains did not change body weight compared with non-whole-grain foods. These trials pooled whole grains, not wheat alone.
All 31 studies, strongest evidence first
The EU lets foods high in wheat bran fiber say it increases stool bulk and speeds up intestinal transit
Two authorized health claims in the EU register (Regulation (EU) No 432/2012), based on a 2010 opinion of the European Food Safety Authority. Both may be used only on foods high in that fiber, and the transit claim also requires a daily intake of at least 10 g of wheat bran fiber.
Each extra gram a day of wheat fiber added about 3.7 g to daily stool weight across trials
Systematic review of 65 intervention studies in generally healthy people, with the wheat fiber coming mostly as wheat bran. Wheat fiber also raised dry stool weight by 0.75 g a day per gram, and shortened transit time by 0.78 hours per gram a day in people whose transit time was longer than 48 hours. The trials differed in design, so the pooled numbers are estimates.
Three daily portions of whole-grain wheat foods for 12 weeks lowered systolic blood pressure by 6 mm Hg in middle-aged adults
Randomized trial in 233 people at relatively high risk of heart disease. After a 4-week run-in on refined foods, they ate a refined diet, whole-grain wheat foods, or whole-grain wheat plus oats. Pulse pressure also fell 3 mm Hg in the whole-grain groups, while other heart-risk markers did not change.
Taking 13.5 g a day of wheat bran fiber for about three years did not prevent colorectal adenomas from coming back
Double-blind trial in 1,429 people who had had an adenoma removed, comparing 13.5 g with 2 g of wheat bran fiber a day. New adenomas turned up in 47.0% of the high-fiber group and 51.2% of the low-fiber group, a gap small enough to be chance (odds ratio 0.88, 0.70 to 1.11).
A whole-grain diet for 6 weeks raised net daily energy loss by 92 kcal compared with a refined-grain diet
Controlled-feeding trial in 81 men and postmenopausal women, with whole grains pooled and not wheat alone: 207 g of whole grains and 40 g of fiber a day against none and 21 g. Resting metabolic rate rose by 43 kcal and stool weight by 76 g a day, while glucose tolerance did not differ significantly. The Bell Institute of Health and Nutrition at General Mills and the USDA funded it, and a General Mills employee was an author.
Eating 60 g or 120 g of whole grains a day for 16 weeks changed none of the heart-risk markers measured
Randomized trial in 316 overweight adults who usually ate under 30 g of whole grains a day. The foods were a range of whole-grain products, including wholewheat bread and pasta, oats and brown rice, so this is not wheat alone. The UK Food Standards Agency funded it, and cereal companies supplied the foods. The authors say 4 months may be too short to show an effect.
Across 26 trials, whole grains did not change body weight compared with non-whole-grain foods
Meta-analysis of randomized trials in 2,060 healthy adults, with whole grains pooled and not wheat alone. Weight differed by 0.06 kg (95% CI -0.09 to 0.20), while body fat fell by a small 0.48 percentage points. The trials lasted 16 weeks or less.
Whole grains for at least 12 weeks made no clear difference to total cholesterol, and no trial measured heart attacks or strokes
Cochrane review of 9 randomized trials with 1,414 people, with whole grains pooled and not wheat alone. The mean difference in total cholesterol was 0.07 (95% CI -0.07 to 0.21), based on low-quality evidence, and no trial ran longer than 16 weeks. Some trials were funded in whole or part by organizations with commercial interests in cereals.
Two weeks of whole wheat bread cut the blood sugar rise after a glucose drink by 27% compared with white bread in adults with prediabetes
Controlled-feeding crossover trial in 39 adults with prediabetes, who ate fully provided diets that differed only in whole wheat or refined white bread, 2 weeks each. Fasting glucose and insulin improved over time on both diets, and inflammation markers did not differ between breads. The trial was small and short, and the response varied with gut bacteria.
Eating 48 g of whole-grain wheat cereal a day for 3 weeks raised stool bifidobacteria and lactobacilli compared with wheat bran cereal
Double-blind crossover study in 31 volunteers who ate whole-grain wheat or wheat bran breakfast cereal, in two 3-week periods. Blood sugar, insulin and blood fats did not differ between the two, the bran cereal raised stool frequency, and no bowel symptoms were reported. Bacterial counts are a step removed from health outcomes.
10 g a day of added wheat fiber in food for 5 days raised stool wet weight, but the same fiber in drinks did not
Two small randomized studies, with 10 and 19 people, tested a purified wheat fiber added to foods or to drinks. Stool dry weight did not change in either study, and gut bacteria were not much altered. The fiber is a concentrate, not whole bran, and its maker, J. Rettenmaier & Söhne, funded the work.
In treated celiac disease, 50 mg of gluten a day for 90 days damaged the gut lining, while 10 mg did not clearly
Double-blind trial in 49 adults with biopsy-proven celiac disease who had followed a gluten-free diet for 2 years or more. They took a capsule with 0, 10 or 50 mg of gluten a day, and the ratio of villus height to crypt depth fell 20% in the 50 mg group. One person on 10 mg relapsed, and the authors concluded that contaminating gluten should stay under 50 mg a day.
In people with irritable bowel syndrome who felt better gluten-free, 68% on gluten and 40% on placebo said symptoms were not controlled
Double-blind trial in 34 people with irritable bowel syndrome and no celiac disease, given gluten (two slices of bread and a muffin a day) or placebo for up to 6 weeks. Pain, bloating and tiredness scored worse on gluten within a week, while markers of gut inflammation and leakiness did not change. The authors concluded that non-celiac gluten intolerance may exist but found no clue to how it works.
Once FODMAPs were cut, gluten caused symptoms in only 8% of people with self-reported gluten sensitivity
Double-blind crossover trial in 37 people with irritable bowel syndrome and self-reported gluten sensitivity, after a 2-week low-FODMAP diet. Symptoms improved on the low-FODMAP diet and worsened to a similar degree on high-gluten (16 g), low-gluten and whey control diets, and a 3-day rechallenge did not reproduce a gluten effect. The authors found no specific or dose-dependent effect of gluten.
In people who believed they were gluten sensitive, fructans, not gluten, raised symptom scores in a 7-day challenge
Double-blind crossover trial in 59 people on a self-started gluten-free diet, without celiac disease, who ate muesli bars with gluten (5.7 g), fructans (2.1 g) or placebo for 7 days each. Overall symptom scores averaged 38.6 on fructans, 34.3 on placebo and 33.1 on gluten, and gluten did not differ from placebo. Fructans are carbohydrates that wheat contains.
A small dose of gluten, 4.375 g a day for a week, made overall symptoms worse than placebo in people with suspected gluten sensitivity
Double-blind crossover trial in 61 adults without celiac disease or wheat allergy who believed gluten caused their symptoms, with 59 completing it. In the per-protocol analysis, bloating, pain, foggy mind and depression were more severe on gluten than on placebo. One short trial that points the other way from the two trials above.
Eating Kamut khorasan wheat products for 8 weeks lowered LDL cholesterol by 7.8% compared with semi-whole-grain modern wheat
Brand-linked, ancient wheat: single-blind crossover trial in 22 healthy people who ate bread, pasta and crackers made from Kamut or from control wheat for 8 weeks each. Total cholesterol fell 4%, inflammation markers fell, and potassium and magnesium rose. The paper says it was supported in part by a grant from Kamut Enterprises of Europe, which sells the Kamut brand.
In type 2 diabetes, 8 weeks of khorasan wheat products lowered insulin by 16.3% and total cholesterol by 3.7%, while modern wheat did not
Brand-linked, ancient wheat: double-blind crossover trial in 21 people with type 2 diabetes, using bread, pasta, crackers and biscuits from organic khorasan (Kamut) or modern wheat semi-whole flour, 8 weeks each. The difference between the two wheats was significant for total and LDL cholesterol, insulin and HOMA. The paper says it was supported in part by Kamut Enterprises of Europe, which also provided the khorasan wheat.
In 20 people with irritable bowel syndrome, 6 weeks of khorasan wheat products eased abdominal pain and bloating compared with modern wheat
Brand-linked, ancient wheat: double-blind crossover trial with bread, pasta, biscuits and crackers made from organic semi-whole-grain khorasan or modern wheat, 6 weeks each. Symptoms and blood inflammation markers improved only after the khorasan period. The khorasan wheat was supplied by Kamut International Limited.
A pooled 10.3% of people report non-celiac gluten or wheat sensitivity, with bloating the most common symptom
Meta-analysis of 25 surveys with 49,476 people in 16 countries; prevalence varied widely between countries. Bloating (71.0%), abdominal discomfort (46.0%) and fatigue (32.1%) were the most common symptoms, women reported it more than men (odds ratio 2.29), and 40% of reporters followed a gluten-free diet. These are self-reports, not tested diagnoses.
Wheat allergy confirmed by food challenge affected about 0.1% of people in Europe, far below the 1.6% who report it
Meta-analysis of 93 studies of the eight big food allergens in Europe. Self-reported lifetime wheat allergy pooled at 1.6% (95% CI 0.9 to 2.3), against 0.1% (0.01 to 0.2) with food-challenge-verified allergy. Wheat allergy is a different condition from celiac disease and gluten sensitivity.
65% of children with wheat allergy had outgrown it by age 12, but a significant minority had not
Follow-up of 103 children at a US referral clinic who had reacted to wheat and had a positive wheat IgE test, with resolution judged by food challenge. Resolution reached 29% by 4 years and 56% by 8 years, and higher wheat IgE levels predicted poorer outcomes. Referral clinic children may not match all children with wheat allergy.
Celiac disease affects about 1.4% of people by blood test and 0.7% by biopsy worldwide
Meta-analysis of 96 studies, with 275,818 people tested for antibodies and 138,792 with biopsy results. Prevalence was 0.4% in South America and 0.8% in Europe and Oceania, higher in women (0.6%) than in men (0.4%), and higher in children (0.9%) than in adults (0.5%). Gluten from wheat, rye and barley is the trigger.
Over 26 years, people eating the most gluten had no higher risk of heart disease than those eating the least
Cohort of 64,714 women and 45,303 men without celiac disease, with gluten from all foods estimated by questionnaire. The highest fifth had a hazard ratio of 0.95 (0.88 to 1.02), and 1.00 after adjusting for whole grains. The authors warn that avoiding gluten may mean eating fewer whole grains.
Eating 90 g of whole grains a day, about three servings, went with about a fifth lower risk of coronary heart disease in cohorts
Pooled whole grains, not wheat alone: meta-analysis of 45 prospective studies. Relative risks per 90 g a day were 0.81 for coronary heart disease, 0.78 for cardiovascular disease and 0.83 for death from any cause. Whole-grain bread, breakfast cereals and added bran each went with lower risk, but refined grains and total grains did not. Cohorts show a link, not proof.
Three servings of whole grains a day went with a lower risk of colorectal cancer (relative risk 0.83)
Pooled whole grains and cereal fiber, not wheat alone: meta-analysis of 25 prospective studies. Each 10 g a day of cereal fiber had a relative risk of 0.90, the same as total fiber. The authors say more detailed studies are needed to rule out residual confounding.
Pooled analyses of fiber and whole grains found a 15 to 30% lower risk of early death and several diseases at the highest fiber intakes
Series of meta-analyses of 185 prospective studies and 58 clinical trials with 4,635 adults, covering fiber and whole grains in general, not wheat alone. Risk was lowest at 25 to 29 g of fiber a day, and certainty was moderate for fiber and low to moderate for whole grains. The New Zealand Health Research Council and the WHO were among the funders.
In 60 German winter wheat varieties from 1891 to 2010, gluten content did not change as breeding advanced
Chemical analysis of flour protein in 60 varieties grown in 3 years. Gliadin and total protein trended down and glutenin trended up, and the harvest year mattered more than the variety. The authors found no evidence of a higher immune-stimulating potential in modern wheat.
Four celiac-active gluten peptides showed no clear rise in 60 wheat varieties from 1891 to 2010
Analysis of flour from 60 German winter wheat varieties grown in 3 years. Harvest year affected the amounts more than variety, and two peptides rose slightly relative to alpha-gliadins over time. The authors conclude that old and modern wheat look similar.
A celiac epitope was more common in modern wheat varieties, while another was less common
Gene analysis of gluten in 36 modern European wheat varieties and 50 landraces, for two celiac epitopes (Glia-α9 and Glia-α20). The dominant one, Glia-α9, was more present in modern varieties and Glia-α20 less, and some old and modern lines had low amounts of both. This looked at gene sequences, not at people.
A survey of US data found no sign that wheat breeding raised wheat protein, a stand-in for gluten
Review of 20th and 21st century United States data on wheat protein, which tracks gluten content. The paper also discusses higher flour intake per person and added vital gluten in foods as other possible factors in celiac disease rates.
Who should be careful with wheat
Most people can eat wheat freely. Take a little care if one of these applies:
- Celiac disease. Wheat contains gluten, so it is off the menu with celiac disease, which affects about 1.4% of people by blood test. In the US, a “gluten-free” label means under 20 parts per million, and in one trial 50 mg of gluten a day damaged the gut lining of treated patients.
- Wheat allergy. Wheat is one of nine major food allergens that US labels must declare. Food-challenge-verified allergy is about 0.1% of people in Europe, and 65% of children in one clinic study had outgrown it by age 12.
- Irritable bowel syndrome or bloating. Monash University says wheat foods are high in FODMAPs, mainly fructans. In a 59-person trial fructans raised symptom scores and gluten did not, so a dietitian trained in FODMAPs can help before you cut out all gluten.
How to choose, store and eat wheat
- Wheat berries: the whole kernel, chewy after soaking overnight and simmering 45 to 60 minutes, and the form this page covers.
- Bulgur: wheat that was parboiled, dried and cracked, so it is ready in 10 to 12 minutes, and the USDA counts it as a whole grain.
- Whole wheat bread and flour: they keep the bran and germ, and 2 weeks of whole wheat bread cut the blood sugar rise by 27% against white bread in adults with prediabetes.
Look for “whole wheat” or “whole grain” first in the ingredient list. Wheat berries keep about 6 months in a cool, dry pantry or a year in the freezer, while whole wheat flour keeps about 3 months in the pantry or 6 in the freezer, because milling breaks the bran layer and lets oxygen reach the germ oils. In the EU’s 2018 monitoring of 12 foods that included wheat grain, EFSA judged long-term exposure to the 177 pesticide residues tested unlikely to be a concern for consumers.
Sources
- Singh P, Arora A, Strand TA, et al. Global prevalence of celiac disease: systematic review and meta-analysis. Clin Gastroenterol Hepatol. 2018.
- Food and Drug Administration. Food labeling: gluten-free labeling of foods. Final rule. Fed Regist. 2013.
- Catassi C, Fabiani E, Iacono G, et al. A prospective, double-blind, placebo-controlled trial to establish a safe gluten threshold for patients with celiac disease. Am J Clin Nutr. 2007.
- The FASTER Act: sesame is the ninth major food allergen. U.S. Food and Drug Administration.
- Spolidoro GCI, Ali MM, Amera YT, et al. Prevalence estimates of eight big food allergies in Europe: updated systematic review and meta-analysis. Allergy. 2023.
- Keet CA, Matsui EC, Dhillon G, et al. The natural history of wheat allergy. Ann Allergy Asthma Immunol. 2009.
- Gluten and IBS: understanding FODMAPs vs gluten. Monash University FODMAP blog.
- Skodje GI, Sarna VK, Minelle IH, et al. Fructan, rather than gluten, induces symptoms in patients with self-reported non-celiac gluten sensitivity. Gastroenterology. 2018.
- Cooking whole grains. Whole Grains Council.
- Storing whole grains. Whole Grains Council.
- Bulgur. Wikipedia.
- Pierson JT, Bond AH, Cao S, et al. Whole wheat bread improves postprandial glucose tolerance in adults with prediabetes. Front Nutr. 2026.
- European Food Safety Authority. The 2018 European Union report on pesticide residues in food. EFSA Journal. 2020.
History of wheat
Wheat farming began in the Fertile Crescent. People gathered wild wheats in West Asia for thousands of years before that, and emmer was being cultivated in the Levant from around 9700 BC. Einkorn was domesticated in southern Turkey, with the earliest evidence after about 8800 BC.
Bread wheat came later, and by accident. It formed only 8,500 to 9,000 years ago, when a farmed tetraploid wheat crossed with Aegilops tauschii, and it spread across the world very soon afterward. The oldest hexaploid wheat DNA found so far is from Çatalhöyük in Turkey, dated to about 6400 to 6200 BC.
Wheat farming then moved outward. Emmer reached Cyprus by 8600 BC and Greece by 6500 BC. Wheat reached Egypt shortly after 6000 BC, Germany and Spain by 5000 BC, and the British Isles and Scandinavia by 4000 BC, then India around 3500 BC and, probably, China around 2600 BC. A museum sample of Egyptian emmer chaff from 1130 to 1000 BC has had its whole genome read.
The Egyptians are credited with developing bread and the oven. The earliest known wheat with enough gluten for yeasted bread comes from a granary at Assiros in Macedonia, dated to 1350 BC. Bulgur is old too: food historian Gil Marks dates it to about 4000 BC in the ancient Middle East. Older types such as einkorn, emmer, spelt and khorasan are still grown, and a 2018 review found their health edge unproven.
Modern wheat is short. Japanese breeders used dwarfing genes to produce the short-stalked variety Norin 10, and plant scientists later showed that these genes interfere with the plant hormone gibberellin. The shorter plants fell over less and gave more grain, and by 1997 semi-dwarf varieties covered 81% of the developing world’s wheat area. In 2011 the cardiologist William Davis blamed this “Frankenwheat” for obesity and disease in the book Wheat Belly, and a 2013 review by cereal scientists concluded that the claims could not be substantiated.
Sources
- Levy AA, Feldman M. Evolution and origin of bread wheat. Plant Cell. 2022.
- International Wheat Genome Sequencing Consortium. Shifting the limits in wheat research and breeding using a fully annotated reference genome. Science. 2018.
- Scott MF, Botigué LR, Brace S, et al. A 3,000-year-old Egyptian emmer wheat genome reveals dispersal and domestication history. Nat Plants. 2019.
- Shewry PR, Hey SJ. The contribution of wheat to human diet and health. Food Energy Secur. 2015.
- Hedden P. The genes of the Green Revolution. Trends Genet. 2003.
- Dinu M, Whittaker A, Pagliai G, Benedettelli S, Sofi F. Ancient wheat species and human health: biochemical and clinical implications. J Nutr Biochem. 2018.
- Brouns F, van Buul VJ, Shewry PR. Does wheat make us fat and sick? J Cereal Sci. 2013.
- Wheat. Wikipedia.
- Bulgur. Wikipedia.
- Wheat Belly. Wikipedia.
Frequently asked questions about wheat
Is wheat good for you?
For most people, yes, when it is whole grain. Whole wheat kernels have 12.2 g of fiber per 100 g, and cohorts linked three servings (90 g) of whole grains a day to a relative risk of 0.81 for coronary heart disease. In a 233-person trial, whole-grain wheat foods lowered systolic blood pressure by 6 mm Hg, but a 316-person trial found no change in heart-risk markers. Wheat is off the menu with celiac disease.
Is whole wheat healthier than white wheat?
Whole wheat has more fiber, and the trials lean its way. Whole-grain flour averaged 13.4 g of fiber per 100 g of dry weight against 3.5 g in white flour, and in 39 adults with prediabetes, whole wheat bread cut the blood sugar rise after a glucose drink by 27% over white bread. The long-term trials were less clear: whole grains did not change heart-risk markers in 316 people or body weight across 26 trials.
Does wheat cause belly fat or weight gain?
Not in the trials. Across 26 trials, whole grains did not change body weight (a 0.06 kg difference), and body fat fell by a small 0.48 percentage points. The book Wheat Belly blamed modern dwarf wheat for obesity, but a 2013 review found its claims could not be substantiated, and an analysis of 60 German varieties from 1891 to 2010 found gluten content did not change. One study did find a celiac epitope more common in modern wheat, so breeding is not fully cleared for celiac disease.
Does wheat cause bloating or inflammation?
It can cause bloating in some people, but gluten is often not the trigger. In a 59-person trial, fructans raised symptom scores while gluten did not differ from placebo, and in a 37-person trial gluten effects showed in only 8% once FODMAPs were cut. One 61-person trial did find worse symptoms on gluten, so the evidence is mixed. Inflammation markers did not differ between whole wheat and white bread in the 39-person prediabetes trial.
Is wheat bran good for constipation?
It helps stool bulk, which is what the EU health claim covers. Across 65 trials, each extra gram of wheat fiber a day added about 3.7 g to stool weight, and transit time shortened only in people whose transit took longer than 48 hours. The EU transit claim needs at least 10 g of wheat bran fiber a day. Wheat bran fiber did not prevent adenomas in a 1,429-person trial.
Is wheat high in protein?
Fairly, for a grain. Dry whole wheat has 11.3 g of protein per 100 g, or 5.4 g in a quarter cup (48 g), which is about 13% of its calories. Wheat protein is low in the essential amino acid lysine, so wheat is not a complete protein on its own.
Is Kamut or ancient wheat healthier than modern wheat?
Possibly, but the evidence is small and brand-linked. Three crossover trials of 20 to 22 people, all from one research group, found better cholesterol, insulin or irritable bowel symptoms on khorasan (Kamut) than on modern wheat, and the Kamut companies funded or supplied them. A 2018 review concluded that it is not possible to say ancient wheats are better. Spelt has its own page: spelt nutrition and benefits.
Are wheat berries gluten free?
No. Wheat berries are whole wheat kernels and contain gluten, so they are not safe with celiac disease. In the US, a “gluten-free” label means under 20 parts per million, and in a 49-person trial, 50 mg of gluten a day damaged the gut lining of treated patients.