Introduction
Anyone asking what is rice bran deserves a direct answer. Rice bran is the thin brown layer between the rice hull and the white, starchy interior of the kernel. Milling strips it away to make white rice. It is a small share of the kernel, yet it carries much of the fiber, B vitamins, minerals, and other bioactive compounds.
Rice is a daily staple for roughly half of the world's population (Hu et al., 2014; Qian et al., 2016). Most of it is eaten white, so its bran rarely reaches a plate. Here I explain what rice bran contains, what research has measured, and how to use it. I have eaten a whole-food plant-based diet since 1999, and stabilized rice bran went into a formula I designed and take.
What Is Rice Bran? A Closer Look
A rice kernel has several parts, and knowing them makes the answer to what is rice bran much clearer. The hull is the hard outer shell, and people cannot digest it. Removing the hull leaves brown rice, which still carries its bran and germ.
Rice bran makes up the outer layers of the edible kernel. Researchers profiling its small molecules catalogued hundreds of compounds, including saccharides, amino acids, fatty acids, vitamins, minerals, and cofactors (Zarei et al., 2017). That method, called metabolomics, measures many small molecules in a sample at once.
Rice bran is usually a shade of brown, and it is less than 10 percent of the kernel by weight. The endosperm is the large white interior, and it is mostly digestible starch. Milling removes the bran and the germ, and the endosperm that remains is white rice.
Brown rice keeps the bran on the kernel, and researchers have compared it with white rice in several populations. In overweight and obese non-menopausal women, investigators measured inflammatory and cardiovascular markers after brown rice replaced white rice (Kazemzadeh et al., 2014). In adults with type 2 diabetes, another team measured waist size and metabolic markers after intake of fermented brown rice lees (Kim et al., 2011). In large cohorts of US men and women, investigators tracked white and brown rice intake against later diabetes diagnoses (Sun et al., 2010). These are studies of whole grains, not of rice bran by itself.
Rice Bran Nutrition Facts per 100 Grams
The clearest way to show rice bran nutrition is a nutrient table. The figures below come from the USDA FoodData Central entry for crude rice bran. I added a 10-gram column since nobody eats 100 grams of rice bran at one sitting.
| Nutrient | Per 100 grams | Per 10 grams |
|---|---|---|
| Energy | 316 kcal | 32 kcal |
| Protein | 13.4 g | 1.3 g |
| Total fat | 20.8 g | 2.1 g |
| Carbohydrate | 49.7 g | 5.0 g |
| Dietary fiber | 21.0 g | 2.1 g |
| Thiamin (vitamin B1) | 2.75 mg | 0.28 mg |
| Niacin (vitamin B3) | 34.0 mg | 3.4 mg |
| Vitamin B6 | 4.07 mg | 0.41 mg |
| Vitamin E (alpha-tocopherol) | 4.92 mg | 0.49 mg |
| Magnesium | 781 mg | 78 mg |
| Phosphorus | 1,680 mg | 168 mg |
| Potassium | 1,480 mg | 148 mg |
| Iron | 18.5 mg | 1.9 mg |
| Zinc | 6.04 mg | 0.60 mg |
| Manganese | 14.2 mg | 1.4 mg |
Source: USDA FoodData Central, SR Legacy, "Rice bran, crude" (FDC ID 169713). The 10-gram column is the 100-gram value divided by 10.
Three features of that profile stand out to me. Rice bran carries about 21 grams of fiber and 13 grams of protein per 100 grams. It is also dense in thiamin, niacin, vitamin B6, magnesium, and manganese.
Those numbers describe crude rice bran analyzed in a laboratory, not a finished supplement. Stabilized products vary with the rice variety, the milling, and the processing. A value on a nutrient table also tells you nothing about how much your body absorbs.
Rice Bran Benefits: What the Research Has Measured
Limits come first in this section. Much of the rice bran literature comes from cell culture and animals, and the human studies are generally small. None of it shows that a food or a dietary supplement treats, cures, or prevents any disease.
The human metabolic studies come mostly from clinical populations rather than healthy adults. Investigators measured blood glucose and serum lipids in adults with type 1 or type 2 diabetes who ate stabilized rice bran (Qureshi et al., 2002). Another team measured metabolic markers in adults with type 2 diabetes given stabilized rice bran (Cheng et al., 2010). A large US cohort analysis with a systematic review related whole grain and bran intake to later diabetes diagnoses (de Munter et al., 2007).
Lipid research follows the same pattern. Rice bran oil was studied in adults with high blood lipids (Kuriyan et al., 2005). Rice bran tocotrienols were studied in adults with high cholesterol (Qureshi et al., 1997). In rats, researchers studied how rice bran tocotrienol and rice bran protein affected cholesterol handling (Shibata et al., 2016; Wang et al., 2015).
Other work occurs in animals. In mice fed a high-fat diet, investigators studied rice bran unsaponifiables and weight gain (Ham et al., 2015). In genetically modified mouse models of breast, prostate, and intestinal tumors, researchers evaluated dietary rice bran (Verschoyle et al., 2007). A later review summarized that laboratory and animal literature (Henderson et al., 2012).
Gut research spans animals and one small human pilot. In mice, rice bran was studied against Salmonella colonization (Kumar et al., 2012; Goodyear et al., 2015). Gnotobiotic piglets are raised free of normal gut bacteria. In those piglets, researchers tested rice bran with probiotics against human rotavirus and norovirus diarrhea (Yang et al., 2015; Lei et al., 2016). In a pilot trial, four of seven healthy adults ate 30 grams of stabilized rice bran daily for four weeks, and three were controls. Researchers then measured shifts in stool bacteria and metabolites (Sheflin et al., 2015). The microbiome works between the gut and the brain, which I discuss in the gut brain connection.
Innate immune activity connects to brain function through inflammatory signaling, which I talk about in inflammation and brain health. To my knowledge, rice bran has not been studied for its effect on brain-derived neurotrophic factor, known as BDNF. My article on BDNF explains why that growth factor matters for cognition.
How to Use Rice Bran: Brown Rice, Powder, and Amounts
The simplest answer to how to use rice bran is to eat brown rice or another whole-grain rice. Red and black rice also keep their bran. Swapping white rice for any of them puts the bran back on your plate.
Rice bran powder is the concentrated option. Raw rice bran contains oils and fat-splitting enzymes, so it turns rancid soon after milling. Stabilized rice bran has been heated to slow that process, and it is the form I would choose. Heat stabilization, and what it changes in the bran, is the subject of my article on stabilized rice bran.
Stabilized rice bran powder stirs easily into oatmeal, smoothies, soups, and baked goods. Start with a small amount, since its fiber content is high. Drink enough fluid along with it, as you would with any fiber-rich food.
No official recommended intake exists for rice bran since it is a food rather than an essential nutrient. The pilot trial in healthy adults used a 30-gram daily serving, which is a large amount for most people. A spoonful or two in food is a more typical everyday use.
Rice bran is gluten free since rice does not contain gluten. That makes it a practical whole-grain option for anyone avoiding gluten. Check the label for processing in a facility shared with wheat.
Is Rice Bran Bad for You? What to Consider
Rice bran is a food, but a food can still disagree with some people. Its fiber content can cause gas or bloating when intake rises quickly. Increasing the amount gradually gives your digestive system time to adjust.
Arsenic deserves a plain discussion, and I would rather raise it than have you find it elsewhere. Rice takes up more arsenic from soil and water than other grain crops, and much of it concentrates in the bran. Researchers testing commercial and specially milled samples found rice bran inorganic arsenic 10 to 20 times higher than in bulk grain (Sun et al., 2008).
That finding describes the raw material, not any particular finished product. It is the reason heavy metal testing matters for rice bran more than for most foods. I explain how exposure is measured in what are heavy metals, and what a lab report can show in third-party tested supplements.
Rice allergy is uncommon, but anyone with a known rice allergy should avoid rice bran. If you are pregnant, nursing, or on prescription medication, check with your physician before adding a rice bran supplement. A short conversation costs you nothing.
What Is Rice Bran Good For? My Top Use Cases
What is rice bran good for, in my view? First, it puts back the fiber, B vitamins, and minerals that milling removes from white rice. Second, it brings fat-soluble compounds such as tocotrienols, a form of vitamin E, that polished rice lacks.
I chose stabilized rice bran for Daily Brain Care as a whole food rather than an isolated compound. It works with aloe polysaccharides, golden flaxseed, and sunflower lecithin in the formula. I take the formula myself, and it fits the whole-food plant-based diet I have followed since 1999.
I want to be clear about what that choice does and does not mean. The studies above tested rice bran alone, often in far larger amounts than any single ingredient in a blend. I do not borrow those findings as product claims. My research background is on my About page.
Conclusion
What is rice bran? It is the outer layer, dense in nutrients, which milling strips from brown rice to make white rice. USDA data show substantial fiber, protein, B vitamins, and minerals per gram. Research on rice bran spans cell culture, animals, and small human studies, and I read it with those limits in mind. Eating whole-grain rice is the simplest way to get it. If you want stabilized rice bran in a whole-food formula, try Daily Brain Care today!
Frequently Asked Questions
What is rice bran?
Rice bran is the thin brown layer of the rice kernel that sits between the inedible hull and the white starchy interior. Milling removes it, along with the germ, to produce white rice. Brown rice keeps it.
How much fiber and protein does rice bran have?
USDA FoodData Central lists about 21 grams of fiber, 13 grams of protein, and 21 grams of fat per 100 grams of crude rice bran. It is also dense in thiamin, niacin, vitamin B6, magnesium, phosphorus, and manganese. Those are laboratory values for crude bran, not for a finished product.
Is rice bran different from rice husk?
Yes, they are different layers of the kernel. The husk, also called the hull, is the inedible outer shell that milling removes first. The bran lies underneath it and is edible, and it stays on the kernel in brown rice.
Is rice bran gluten free?
Yes, rice and rice bran do not contain gluten. Cross-contact can still occur in a facility that also handles wheat. Check the label if you need to avoid gluten strictly.
What has research measured about rice bran and cholesterol?
Rice bran oil was studied in adults with high blood lipids (Kuriyan et al., 2005). Rice bran tocotrienols were studied in adults with high cholesterol (Qureshi et al., 1997). In rats, rice bran protein was studied for its effect on cholesterol handling (Wang et al., 2015). Anyone managing a diagnosed cholesterol concern should work with a qualified clinician rather than rely on any single food.
Is rice bran a superfood?
Superfood is a marketing term rather than a scientific category, so I avoid it. What I can say is that rice bran is unusually nutrient-dense per gram, as the USDA figures show. That density is why I value it, not a label.
References
Cheng, H. H., Huang, H. Y., Chen, Y. Y., Huang, C. L., Chang, C. J., Chen, H. L., & Lai, M. H. (2010). Ameliorative effects of stabilized rice bran on type 2 diabetes patients. Annals of Nutrition and Metabolism, 56(1), 45–51. https://doi.org/10.1159/000265850
de Munter, J. S., Hu, F. B., Spiegelman, D., Franz, M., & van Dam, R. M. (2007). Whole grain, bran, and germ intake and risk of type 2 diabetes: A prospective cohort study and systematic review. PLOS Medicine, 4(8), e261. https://doi.org/10.1371/journal.pmed.0040261
Goodyear, A., Kumar, A., Ehrhart, E. J., Swanson, K. S., Grusak, M. A., Leach, J. E., Dow, S. W., McClung, A., & Ryan, E. P. (2015). Dietary rice bran supplementation prevents Salmonella colonization differentially across varieties and by priming intestinal immunity. Journal of Functional Foods, 18(Part A), 653–664. https://doi.org/10.1016/j.jff.2015.08.027
Ham, H., Sung, J., & Lee, J. (2015). Effect of rice bran unsaponifiables on high-fat diet-induced obesity in mice. Journal of Food Biochemistry, 39(6), 673–681. https://doi.org/10.1111/jfbc.12170
Henderson, A. J., Ollila, C. A., Kumar, A., Borresen, E. C., Raina, K., Agarwal, R., & Ryan, E. P. (2012). Chemopreventive properties of dietary rice bran: Current status and future prospects. Advances in Nutrition, 3(5), 643–653. https://doi.org/10.3945/an.112.002303
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Kazemzadeh, M., Safavi, S. M., Nematollahi, S., & Nourieh, Z. (2014). Effect of brown rice consumption on inflammatory marker and cardiovascular risk factors among overweight and obese non-menopausal female adults. International Journal of Preventive Medicine, 5(4), 478–488. https://pubmed.ncbi.nlm.nih.gov/24829736
Kim, T. H., Kim, E. K., Lee, M. S., Lee, H. K., Hwang, W. S., Choe, S. J., Kim, T. Y., Han, S. J., Kim, H. J., Kim, D. J., & Lee, K. W. (2011). Intake of brown rice lees reduces waist circumference and improves metabolic parameters in type 2 diabetes. Nutrition Research, 31(2), 131–138. https://doi.org/10.1016/j.nutres.2011.01.010
Kumar, A., Henderson, A., Forster, G. M., Goodyear, A. W., Weir, T. L., Leach, J. E., Dow, S. W., & Ryan, E. P. (2012). Dietary rice bran promotes resistance to Salmonella enterica serovar Typhimurium colonization in mice. BMC Microbiology, 12, 71. https://doi.org/10.1186/1471-2180-12-71
Kuriyan, R., Gopinath, N., Vaz, M., & Kurpad, A. V. (2005). Use of rice bran oil in patients with hyperlipidaemia. National Medical Journal of India, 18(6), 292–296. https://pubmed.ncbi.nlm.nih.gov/16483027
Lei, S., Ramesh, A., Twitchell, E., Wen, K., Bui, T., Weiss, M., Yang, X., Kocher, J., Li, G., Giri-Rachman, E., Trang, N. V., Jiang, X., Ryan, E. P., & Yuan, L. (2016). High protective efficacy of probiotics and rice bran against human norovirus infection and diarrhea in gnotobiotic pigs. Frontiers in Microbiology, 7, 1699. https://doi.org/10.3389/fmicb.2016.01699
Qian, Q., Guo, L., Smith, S. M., & Li, J. (2016). Breeding high-yield superior-quality hybrid super-rice by rational design. National Science Review, 3(3), 283–294. https://doi.org/10.1093/nsr/nww006
Qureshi, A. A., Bradlow, B. A., Salser, W. A., & Brace, L. D. (1997). Novel tocotrienols of rice bran modulate cardiovascular disease risk parameters of hypercholesterolemic humans. Journal of Nutritional Biochemistry, 8(5), 290–298. https://doi.org/10.1016/S0955-2863(97)89667-2
Qureshi, A. A., Sami, S. A., & Khan, F. A. (2002). Effects of stabilized rice bran, its soluble and fiber fractions on blood glucose levels and serum lipid parameters in humans with diabetes mellitus types I and II. Journal of Nutritional Biochemistry, 13(3), 175–187. https://doi.org/10.1016/s0955-2863(01)00211-x
Sheflin, A. M., Borresen, E. C., Wdowik, M. J., Rao, S., Brown, R. J., Heuberger, A. L., Broeckling, C. D., Weir, T. L., & Ryan, E. P. (2015). Pilot dietary intervention with heat-stabilized rice bran modulates stool microbiota and metabolites in healthy adults. Nutrients, 7(2), 1282–1300. https://doi.org/10.3390/nu7021282
Shibata, A., Kawakami, Y., Kimura, T., Miyazawa, T., & Nakagawa, K. (2016). α-Tocopherol attenuates the triglyceride- and cholesterol-lowering effects of rice bran tocotrienol in rats fed a Western diet. Journal of Agricultural and Food Chemistry, 64(26), 5361–5366. https://doi.org/10.1021/acs.jafc.6b02228
Sun, G. X., Williams, P. N., Carey, A. M., Zhu, Y. G., Deacon, C., Raab, A., Feldmann, J., Islam, R. M., & Meharg, A. A. (2008). Inorganic arsenic in rice bran and its products are an order of magnitude higher than in bulk grain. Environmental Science & Technology, 42(19), 7542–7546. https://doi.org/10.1021/es801238p
Sun, Q., Spiegelman, D., van Dam, R. M., Holmes, M. D., Malik, V. S., Willett, W. C., & Hu, F. B. (2010). White rice, brown rice, and risk of type 2 diabetes in US men and women. Archives of Internal Medicine, 170(11), 961–969. https://doi.org/10.1001/archinternmed.2010.109
U.S. Department of Agriculture, Agricultural Research Service. (2019). Rice bran, crude (FDC ID 169713) [Data set]. FoodData Central, SR Legacy. https://fdc.nal.usda.gov/food-details/169713/nutrients
Verschoyle, R. D., Greaves, P., Cai, H., Edwards, R. E., Steward, W. P., & Gescher, A. J. (2007). Evaluation of the cancer chemopreventive efficacy of rice bran in genetic mouse models of breast, prostate and intestinal carcinogenesis. British Journal of Cancer, 96(2), 248–254. https://doi.org/10.1038/sj.bjc.6603539
Wang, J., Shimada, M., Kato, Y., Kusada, M., & Nagaoka, S. (2015). Cholesterol-lowering effect of rice bran protein containing bile acid-binding proteins. Bioscience, Biotechnology, and Biochemistry, 79(3), 456–461. https://doi.org/10.1080/09168451.2014.978260
Yang, X., Twitchell, E., Li, G., Wen, K., Weiss, M., Kocher, J., Lei, S., Ramesh, A., Ryan, E. P., & Yuan, L. (2015). High protective efficacy of rice bran against human rotavirus diarrhea via enhancing probiotic growth, gut barrier function, and innate immunity. Scientific Reports, 5, 15004. https://doi.org/10.1038/srep15004
Zarei, I., Brown, D. G., Nealon, N. J., & Ryan, E. P. (2017). Rice bran metabolome contains amino acids, vitamins & cofactors, and phytochemicals with medicinal and nutritional properties. Rice, 10(1), 24. https://doi.org/10.1186/s12284-017-0157-2
