Brown rice

Health benefits

Why brown, not white, rice matters nutritionally

The difference between brown rice and white rice goes beyond color. A whole grain of rice has several layers. Only the outermost layer, the hull, is removed to produce brown rice, preserving the nutrient-dense bran and germ underneath. Further milling strips away the bran and most of the germ. Polishing then removes the aleurone layer, which contains essential fatty acids. Mills remove this layer because those fats oxidize rapidly once exposed to air, shortening shelf life. What remains is a refined starch largely stripped of its original nutrients.

One cup (195g) of cooked brown rice provides 1.76 mg of manganese (77% DV), 19.11 mcg of selenium (35% DV), 161.85 mg of phosphorus (23% DV), 0.19 mg of copper (21% DV), 83.85 mg of magnesium (20% DV), and 2.98 mg of niacin (19% DV). The complete milling and polishing that converts brown rice into white rice destroys 67% of the vitamin B3, 80% of the vitamin B1, 90% of the vitamin B6, half of the manganese, half of the phosphorus, 60% of the iron, and all of the dietary fiber and essential fatty acids. U.S. law requires fully milled and polished white rice to be “enriched” with vitamins B1, B3, and iron. The synthetic forms added back differ from those in the intact grain, and at least 11 lost nutrients are never replaced.

Manganese: energy production and antioxidant protection

Manganese is a cofactor for enzymes that metabolize protein and carbohydrates into usable energy, and it participates in the synthesis of fatty acids needed for myelin maintenance in the nervous system. The body also requires manganese for cholesterol synthesis, which feeds steroid hormone production. Beyond metabolism, manganese is a structural component of superoxide dismutase (SOD), the antioxidant enzyme stationed inside mitochondria. SOD neutralizes superoxide radicals generated as byproducts of oxidative phosphorylation.

Women who eat whole grains weigh less

A Harvard Medical School / Brigham and Women’s Hospital study, published in the American Journal of Clinical Nutrition, tracked over 74,000 female nurses aged 38-63 for 12 years. Weight gain correlated inversely with intake of high-fiber, whole-grain foods and positively with refined-grain intake. Women consuming the most dietary fiber from whole grains were 49% less likely to gain weight compared to those eating primarily refined grains.

Brown rice delivers both fiber and selenium

Brown rice supplies fiber and selenium in the same grain, two components relevant to colon cancer risk. The fiber reduces transit time through the colon, limiting how long potential carcinogens contact epithelial cells. Selenium, meanwhile, participates in antioxidant defense and DNA repair pathways that counteract early-stage cellular damage.

Selenium is incorporated into selenoproteins that function in thyroid hormone conversion (deiodinases), antioxidant defense (glutathione peroxidases), and immune cell signaling. Prospective studies, intervention trials, and animal models have collectively shown an inverse correlation between selenium intake and cancer incidence. At the cellular level, selenium compounds induce DNA repair in damaged cells, inhibit proliferation of aberrant cells, and trigger apoptosis, the programmed self-destruction sequence that eliminates abnormal cells before they can multiply.

Selenium occupies the active site of glutathione peroxidase, an enzyme the liver relies on to neutralize peroxides and reactive oxygen species. When glutathione peroxidase activity drops due to insufficient selenium, these reactive molecules accumulate and damage cellular DNA, a process that can initiate carcinogenesis.

Selenium also works with vitamin E across several antioxidant systems: vitamin E scavenges lipid peroxyl radicals in cell membranes, while selenium-dependent glutathione peroxidases reduce hydrogen peroxide and lipid hydroperoxides in the cytoplasm. This complementary activity has been linked in epidemiological studies to lower cardiovascular risk and reduced inflammatory markers relevant to conditions like asthma and rheumatoid arthritis.

Lower cholesterol with whole brown rice

Rice bran oil contains compounds that reduce LDL cholesterol.

Marlene Most and colleagues at Louisiana State University tested rice bran and rice bran oil in volunteers with moderately elevated cholesterol. Rice bran oil lowered LDL cholesterol.

The study, published in the American Journal of Clinical Nutrition, was divided into two parts. First, 26 subjects ate a diet including 13-22g of dietary fiber each day for three weeks, after which 13 switched to a diet that added defatted rice bran to double their fiber intake for five weeks. In the second part of the study, a randomized crossover trial, 14 subjects ate a diet with rice bran oil for 10 weeks.

The defatted rice bran alone did not lower cholesterol. The rice bran oil, however, reduced LDL by 7%. Because all diets contained similar fatty acid profiles, the researchers attributed the effect to unsaponifiable compounds in the oil, including gamma-oryzanol, phytosterols, and tocotrienols. Whole brown rice delivers these same unsaponifiable fractions alongside its fiber, magnesium, and B vitamins.

Cardiovascular benefits for postmenopausal women

Postmenopausal women with high cholesterol, high blood pressure, or other signs of cardiovascular disease (CVD) may benefit from eating whole grains, including brown rice, at least 6 times per week.

A 3-year prospective study of over 200 postmenopausal women with CVD, published in the American Heart Journal, shows that those eating at least 6 servings of whole grains each week experienced both:

• Slowed progression of atherosclerosis, the build-up of plaque that narrows the vessels through which blood flows, and
• Less progression in stenosis, the narrowing of the diameter of arterial passageways.

The women’s intake of fiber from fruits, vegetables and refined grains was not associated with a lessening in CVD progression.

Phytonutrients comparable in activity to those in vegetables and fruits

Rui Hai Liu, M.D., Ph.D., and colleagues at Cornell University, presenting at the American Institute for Cancer Research (AICR) International Conference on Food, Nutrition and Cancer, showed that whole grains contain phytonutrients whose activity had been systematically overlooked.

The reason: standard assays measured only “free” phenolics, which dissolve quickly and absorb directly into the bloodstream. They missed the “bound” forms, which are covalently attached to cell wall polysaccharides and released only when intestinal bacteria ferment the fiber matrix during digestion.

Phenolics, powerful antioxidants that work in multiple ways to prevent disease, are one major class of phytonutrients that have been widely studied. Included in this broad category are such compounds as quercetin, curcumin, ellagic acid, catechins, and many others that appear frequently in the health news.

When Dr. Liu and his colleagues measured the relative amounts of phenolics, and whether they were present in bound or free form, in common fruits and vegetables like apples, red grapes, broccoli and spinach, they found that phenolics in the “free” form averaged 76% of the total number of phenolics in these foods. In whole grains, however, “free” phenolics accounted for less than 1% of the total, while the remaining 99% were in “bound” form.

By applying the same “free”-phenolic assay used for produce, researchers had vastly underestimated whole-grain antioxidant capacity.

When Dr. Liu’s team measured total antioxidant activity (free plus bound, expressed as micromoles of vitamin C equivalent per gram), the gap between food groups narrowed: broccoli scored 80, spinach 81, apple 98, banana 65. Among whole grains, corn scored 181, whole wheat 77, oats 75, and brown rice 56.

These findings help explain an apparent paradox: populations eating diets high in fiber-containing whole grains consistently show lower colon cancer risk, yet clinical trials using isolated fiber supplements produce inconsistent results. The difference likely lies in the bound phenolics and other phytonutrients that accompany fiber in the intact grain. A whole wheat kernel consists of endosperm (starch), bran, and germ. Refining removes the bran and germ. Those two fractions represent only 15-17% of the grain’s weight but contain 83% of its phenolics. “Different plant foods have different phytochemicals,” Dr. Liu said. “These substances go to different organs, tissues and cells, where they perform different functions.”

Lignans and heart disease protection

Whole grains, including brown rice, supply plant lignans that intestinal bacteria convert into mammalian lignans such as enterolactone. Enterolactone has weak estrogenic activity and has been associated in epidemiological studies with lower risk of hormone-dependent cancers and cardiovascular disease. Nuts, seeds, and berries also supply plant lignans; coffee, tea, and wine contribute smaller amounts. A Danish study published in the Journal of Nutrition measured blood enterolactone in over 850 postmenopausal women. Those eating the most whole grains had significantly higher circulating enterolactone. Women who ate more cabbage and leafy vegetables also showed elevated levels.

Metabolic syndrome risk reduction

Not all carbohydrates behave the same way in the body, just as not all fats do. Saturated and trans fats raise cardiovascular risk; omega-3 fats lower it. The same principle applies to grains: refined grains (white breads, cookies, pastries, white pasta and rice) are linked to weight gain, insulin resistance, and metabolic syndrome, while whole grains show the opposite association.

Metabolic syndrome is defined by a cluster of conditions: visceral obesity, low HDL cholesterol, elevated triglycerides, and high blood pressure. Together, these features strongly predict both type 2 diabetes and cardiovascular disease.

An analysis of data from over 2,800 participants in the Framingham Offspring Study, published in Diabetes Care, found that both insulin resistance and metabolic syndrome prevalence were significantly lower among those eating the most cereal fiber from whole grains. Metabolic syndrome prevalence dropped 38% in the highest whole-grain-fiber group. Participants whose diets had the highest glycemic index and glycemic load were 141% more likely to have metabolic syndrome compared to those eating predominantly whole, high-fiber foods: whole grains, legumes, vegetables, and fruits.

The researchers concluded: “Given that both a high cereal fiber content and lower glycemic index are attributes of wholegrain foods, recommendation to increase wholegrain intake may reduce the risk of developing the metabolic syndrome.”

Brown rice and other whole grains lower type 2 diabetes risk

Brown rice and other whole grains supply magnesium, a mineral that acts as a cofactor for more than 300 enzymes, including those governing glucose metabolism and insulin secretion.

The FDA permits foods that contain at least 51% whole grains by weight (and are also low in fat, saturated fat, and cholesterol) to display a health claim stating consumption is linked to lower risk of heart disease and certain cancers. Now, research suggests regular consumption of whole grains also reduces risk of type 2 diabetes. (van Dam RM, Hu FB, Diabetes Care).

In this 8-year trial, involving 41,186 particpants of the Black Women’s Health Study, research data confirmed inverse associations between magnesium, calcium and major food sources in relation to type 2 diabetes that had already been reported in predominantly white populations.

Risk of type 2 diabetes was 31% lower in black women who frequently ate whole grains compared to those eating the least of these magnesium-rich foods. When the women’s dietary intake of magnesium was considered by itself, a beneficial but lesser (19%) reduction in risk of type 2 diabetes was found, indicating that whole grains offer benefits for blood sugar control beyond their magnesium content alone. Daily consumption of low-fat dairy foods was also helpful, lowering risk of type 2 diabetes by 13%.

Magnesium: from nerve function to bone structure

Magnesium (83.85 mg per cooked cup, 20% DV) regulates nerve and muscle tone by counterbalancing calcium. In nerve cells, magnesium acts as a physiological calcium channel blocker, preventing calcium from flooding in and triggering excessive activation. This gating mechanism keeps nerves, blood vessels, and the muscles they innervate in a relaxed state. When dietary magnesium runs low, calcium enters unopposed, and nerve cells fire excessively, leading to muscle spasms, vasoconstriction, and the airway constriction seen in asthma. The same mechanism links magnesium deficiency to high blood pressure, migraine headaches, and increased heart attack risk.

About two-thirds of the body’s magnesium resides in bone. Part of it integrates into the hydroxyapatite crystal lattice, contributing to physical bone structure. The remainder sits on bone surfaces, functioning as a mineral reserve the body draws from when circulating magnesium dips.

Brown rice may also raise blood levels of nitric oxide, a signaling molecule that dilates blood vessels and inhibits both oxidative modification of LDL cholesterol and leukocyte adhesion to the vascular wall (two early steps in atherosclerotic plaque formation). A study published in the British Journal of Nutrition found that diets high in rice protein increased circulating nitric oxide.

In this study, mice bred to lack apolipoprotein E (a protein central to cholesterol transport in both mice and humans) received purified diets containing casein, rice protein, or soy protein. The casein-fed mice developed the largest atherosclerotic lesions. Mice on rice or soy protein had elevated blood levels of L-arginine, the amino acid precursor to nitric oxide, and higher nitric oxide metabolites compared to the casein group. However, the L-arginine content of the rice and soy diets alone did not account for the degree of protection observed, leading researchers to conclude that additional cardioprotective compounds in these foods contributed to the effect.

Fiber content and its effects

Brown rice fiber binds bile acids in the intestine, increasing their fecal excretion and prompting the liver to pull cholesterol from the blood to synthesize replacements. This mechanism contributes to lower circulating cholesterol. Fiber also slows glucose absorption, helping stabilize blood sugar, which makes brown rice a practical grain for people managing diabetes. As noted above, the same fiber reduces the contact time between potential carcinogens and colonic epithelial cells. It also adds bulk to stool, normalizing bowel transit and reducing constipation.

Fiber from whole grains and fruit linked to lower breast cancer risk

Analysis of fiber intake among 35,972 participants in the UK Women’s Cohort Study found that diets high in fiber from whole grains and fruit were associated with lower breast cancer incidence in pre-menopausal women (Cade JE, Burley VJ, et al., International Journal of Epidemiology).

Pre-menopausal women eating the most fiber (>30 grams daily) more than halved their risk of developing breast cancer, enjoying a 52% lower risk of breast cancer compared to women whose diets supplied the least fiber (<20 grams/day).

Fiber supplied by whole grains offered the most protection. Pre-menopausal women eating the most whole grain fiber (at least 13 g/day) had a 41% reduced risk of breast cancer, compared to those with the lowest whole grain fiber intake (4 g or less per day).

Fiber from fruit was also protective. Pre-menopausal women whose diets supplied the most fiber from fruit (at least 6 g/day) had a 29% reduced risk of breast cancer, compared to those with the lowest fruit fiber intake (2 g or less per day).

Practical Tip: As the following table shows, reaching at least 13 grams of whole grain fiber and 6 grams of fiber from fruit each day is straightforward with common foods.

Food

Fiber Content in Grams

Oatmeal, 1 cup

3.98

Whole wheat bread, 1 slice

2

Whole wheat spaghetti, 1 cup

6.3

Brown rice, 1 cup

3.5

Barley, 1 cup

13.6

Buckwheat, 1 cup

4.54

Rye, 1/3 cup

8.22

Corn, 1 cup

4.6

Apple, 1 medium with skin

5.0

Banana, 1 medium

4.0

Blueberries, 1 cup

3.92

Orange, 1 large

4.42

Pear, 1 large

5.02

Prunes, 1/4 cup

3.02

Strawberries, 1 cup

3.82

Raspberries, 1 cup

8.36

*Fiber content can vary between brands. Source: esha Research, Food Processor for Windows, Version 7.8

Insoluble fiber and gallstone prevention

A study published in the American Journal of Gastroenterology linked high insoluble fiber intake, from foods like brown rice, to lower gallstone incidence in women.

Studying the overall fiber intake and types of fiber consumed over a 16 year period by over 69,000 women in the Nurses Health Study, researchers found that those consuming the most fiber overall (both soluble and insoluble) had a 13% lower risk of developing gallstones compared to women consuming the fewest fiber-rich foods.

Those eating the most foods rich in insoluble fiber gained even more protection against gallstones: a 17% lower risk compared to women eating the least. And the protection was dose-related; a 5-gram increase in insoluble fiber intake dropped risk dropped 10%.

The proposed mechanisms: insoluble fiber accelerates intestinal transit, reduces bile acid secretion (excess bile acids contribute to gallstone formation), improves insulin sensitivity, and lowers triglycerides. Beyond whole grains, insoluble fiber is found in nuts and the edible skin of tomatoes, cucumbers, squash, apples, berries, and pears. Beans supply both insoluble and soluble fiber.

Whole grains and fish linked to lower childhood asthma

The American Lung Association estimates nearly 20 million Americans have asthma, accounting for over 14 million lost school days annually and an economic cost exceeding $16.1 billion.

Data from the International Study on Allergy and Asthma in Childhood suggest that higher consumption of whole grains and fish could cut childhood asthma risk by roughly 50% (Tabak C, Wijga AH, Thorax).

The researchers, from the Dutch National Institute of Public Health and the Environment, Utrecht University, University Medical Center Groningen, used food frequency questionnaires completed by the parents of 598 Dutch children aged 8-13 years. They assessed the children’s consumption of a range of foods including fish, fruits, vegetables, dairy and whole grain products. Data on asthma and wheezing were also assessed using medical tests as well as questionnaires.

While no association between asthma and intake of fruits, vegetables, and dairy products was found (a result at odds with other studies that have supported a link between antioxidant intake, particularly vitamins C and E, and asthma), the children’s intake of both whole grains and fish was significantly linked to incidence of wheezing and current asthma.

In children with a low intake of fish and whole grains, the prevalence of wheezing was almost 20%, but was only 4.2% in children with a high intake of both foods. Low intake of fish and whole grains also correlated with a much higher incidence of current asthma (16.7%). compared to only a 2.8% incidence of current asthma among children with a high intake of both foods.

After adjusting results for possible confounding factors, such as the educational level of the mother, and total energy intake, high intakes of whole grains and fish were found to be associated with a 54 and 66% reduction in the probability of being asthmatic, respectively.

The probability of asthma with bronchial hyperresponsiveness (BHR), defined as increased airway sensitivity to constriction triggers, dropped by 72% with high whole grain intake and 88% with high fish intake. Lead researcher Cora Tabak commented, “The rise in the prevalence of asthma in western societies may be related to changed dietary habits.” Typical Western diets tend to be low in anti-inflammatory compounds found in these foods, particularly the omega-3 fats (EPA, DHA) from cold-water fish and the magnesium and vitamin E provided by whole grains. One caution: wheat is a common food allergen associated with asthma and may need to be avoided in sensitized individuals.

Meta-analysis of whole grains and cardiovascular protection

Whole grain consumption has been linked across studies to lower rates of atherosclerosis, ischemic stroke, diabetes, insulin resistance, obesity, and premature death. A meta-analysis and editorial published in the American Journal of Clinical Nutrition examined why. Across 7 studies including more than 150,000 participants, those with the highest dietary fiber intake had 29% lower cardiovascular disease risk.

Fiber’s role extends beyond bulking. Wheat bran, which constitutes 15% of the whole-grain kernel but is nearly absent from refined flour, concentrates minerals, phenolic acids, lignans, and other phytonutrients alongside its fiber. Whole grains also contain cholesterol-lowering compounds: polyunsaturated fatty acids, oligosaccharides, plant sterols and stanols, and saponins.

The antioxidant profile of whole grains is unusually broad, spanning water-soluble, fat-soluble, and insoluble forms. These include vitamin E, tocotrienols, selenium, phenolic acids, and phytic acid. Because bound and free forms release at different rates during digestion, antioxidant activity persists throughout the gastrointestinal tract. Wheat bran’s antioxidant capacity, for instance, is 20 times that of refined wheat flour. Population studies consistently associate whole-food antioxidant intake with cardiovascular protection, even though isolated antioxidant supplements have shown mixed results. The likely explanation: oxidative modification of LDL cholesterol is an early step in atherosclerosis, and the diverse antioxidant matrix in whole grains interrupts this process at multiple points.

Like soybeans, whole grains supply phytoestrogens that may influence blood cholesterol, vascular elasticity, and bone metabolism. Gut bacteria convert the plant lignans in whole grains into enterolactone and enterodiol. In Finnish men, blood enterolactone levels correlated inversely not only with cardiovascular death but with all-cause mortality.

Lower insulin levels likely contribute as well. Insulin resistance underlies much of the cardiovascular, diabetic, and obesity risk in Western populations. Whole grains improve insulin sensitivity by lowering dietary glycemic index while simultaneously increasing fiber, magnesium, and vitamin E intake. Current evidence supports at least 3 servings of whole grains daily.

Description

Rice supplies as much as half the daily calories for half the world’s population. In Thailand, the phrase “to eat” translates literally as “to eat rice.”

Over 8,000 rice varieties exist. They are typically grouped by grain length: short, medium, or long. Short grain has the highest amylopectin content, producing the stickiest cooked texture. Long grain, higher in amylose, cooks into separate, fluffy kernels. Medium grain falls between the two.

The scientific name for rice is Oryza sativa.

Rice is also classified by its degree of milling. Brown rice (also called whole rice or cargo rice) retains its bran and germ after hull removal. White rice has been milled and polished, stripping away both layers and the nutrients they contain.

Popular varieties in the United States include:

• Arborio: A round grain, starchy white rice, traditionally used to make the Italian dish risotto.
• Basmati: An aromatic rice that has a nutlike fragrance, delicate flavor and light texture.
• Sweet rice: Almost translucent when it is cooked, this very sticky rice is traditionally used to make sushi and mochi.
• Jasmine: A soft-textured long grain aromatic rice that is available in both brown and white varieties.
• Bhutanese red rice: Grown in the Himalayas, this red colored rice has a nutty, earthy taste.
• Forbidden rice: A black colored rice that turns purple upon cooking and has a sweet taste and sticky texture.

History

Rice was long believed to have been first cultivated in China around 6,000 years ago. Archaeological discoveries have since pushed that date back to roughly 9,000 years, based on primitive rice seeds and farm tools excavated in the Yangtze River valley.

For the majority of its long history, rice was a staple only in Asia. Not until Arab travelers introduced rice into ancient Greece, and Alexander the Great brought it to India, did rice find its way to other corners of the world. Subsequently, the Moors brought rice to Spain in the 8th century during their conquests, while the Crusaders were responsible for bringing rice to France. Rice was introduced into South America in the 17th century by the Spanish during their colonization of this continent.

Most of the world’s rice is grown in Asia. Thailand, Vietnam, and China are the three largest exporters.

How to select and store

Brown rice is available prepackaged and in bulk bins. Check for a “use-by” date on packaged brown rice; the oils in its intact germ can go rancid over time.

Research suggests that some non-organic U.S. long grain rice contains 1.4 to 5 times more arsenic than rice from Europe, India, or Bangladesh. Choosing organically grown rice reduces this exposure. (See Individual Concerns below for details.)

For bulk purchases, confirm that bins are covered and that the store turns inventory frequently. Avoid any rice showing signs of moisture.

Brown rice should be stored in an airtight container in the refrigerator because its germ oils oxidize at room temperature. Refrigerated, it keeps for about six months. White rice, lacking the germ, can be stored in a cool, dry cupboard for up to one year.

Cooked rice storage carries genuine food safety considerations. Most food safety organizations recommend no more than 4-7 days of refrigerator storage. The conservative approach: cook only what will be consumed that day or the next. Bacillus cereus spores survive cooking and can germinate in cooked rice left at room temperature, producing emetic and diarrheal toxins. Certain fungi can also convert tryptophan in stored rice into alpha-picolinic acid, which in excessive amounts triggers hypersensitivity reactions. The fungus Fusarium can produce T-2 toxin, one of roughly 300 mycotoxins found across grains when mold develops. Most research on these toxins addresses agricultural-level conditions rather than home storage, but the precautionary approach is sound. Keep cooked rice in a sealed container, refrigerate promptly, and consume within one day.

Tips for preparing and cooking

Tips for preparing brown rice

Rinse rice under running water before cooking, especially bulk-purchased rice, removing any visible debris. Use a 1:2 ratio of rice to boiling water or broth. Once the liquid returns to a boil, reduce heat, cover, and simmer for about 45 minutes.

Wash medium grain and round varieties (like Arborio) under cool running water before cooking to remove surface starch and prevent clumping.

For basmati rice, soak in a bowl of cool water before cooking. Stir and replace the water four or five times until it runs clear rather than milky. This removes excess surface starch and yields a lighter, more separated grain.

How to enjoy

Quick serving ideas

• Heat up cooked rice with milk or soymilk. Add in cinnamon, nutmeg, raisins and honey for a delicious rice pudding.
• Make homemade vegetable sushi rolls by wrapping brown rice and your favorite vegetables in sheets of well-moistened nori.
• Use rice leftovers for cold rice salads that are great for on-the-go lunches. Be creative and add either chicken or tofu plus your favorite vegetables, nuts, herbs and spices.
• For a simple yet delicious lunch or dinner entrée, serve beans and rice accompanied by the vegetables of your choice.
• Rice as a side dish need not be served plain - spruce it up with toppings such as nuts, sesame seeds, sauteed mushrooms, and scallions.
• Place rice and chopped vegetables in a pita bread, top with your favorite dressing, and enjoy a quick and easy lunch meal.

For recipe ideas, see Recipes.

Nutritional profile

One cup (195g) of cooked brown rice provides 1.76 mg of manganese (77% DV), along with meaningful amounts of selenium (35% DV), phosphorus (23% DV), copper (21% DV), magnesium (20% DV), and niacin (19% DV), all at a cost of 216 calories.

Individual concerns

Brown rice is not a commonly allergenic food and is not known to contain measurable amounts of oxalates or purines. In fact, the hypoallergenic (low-allergy) nature of whole grain, organic brown rice makes it a grain alternative commonly recommended by healthcare practitioners.