Choose whole grains over processed varieties, such as white rice and white flour. They all have about the same amount of carbohydrates; otherwise, processed rice and wheat have half and sometimes even less than half -- of the nutrients found in whole-grain rice and wheat. Processed grains that have been enriched gain back some of the vitamins and minerals but none of the fiber.
Brown rice and whole-grain wheat have about the same amount of minerals. Wheat bran bread has slightly more calcium, magnesium, phosphorus and zinc, but you can count on getting 3 to 9 percent of the recommended daily intake of all four nutrients from just one slice of either rice or wheat bran bread. Both of give men 12 percent of their recommended daily intake of iron, while women get 5 percent.
Whole-grain wheat has two to three times more fiber than brown rice. One cup of whole-grain wheat flour has double the fiber found in brown-rice flour, while one slice of wheat bran bread has 3.5 grams of fiber compared to 1 gram in one slice of rice bran bread, according to the USDA Nutrient Data Laboratory. Both grains provide soluble and insoluble fiber, but they have a significantly higher percentage of insoluble fiber. Insoluble fiber helps food move through the digestive tract, prevents constipation, lowers the risk of developing diverticular disease and relieves symptoms of irritable bowel syndrome.
When it comes to vitamin content, brown rice and whole-grain wheat have similar nutritional values, except for folate. Both grains are a good source of energy-providing thiamine, niacin and riboflavin. They both have a small amount of vitamin E. But whole-grain wheat is a better source of folate. One slice of wheat bran bread provides 14 percent of the recommended daily intake of folate. That's almost double the amount in one slice of rice bran bread. Folate removes homocysteine from the blood, which may lower the risk of cardiovascular disease. Folate is also essential for the creation and growth of new cells, making it especially important during fast periods of growth in pregnancy and childhood.
Both grains provide phytonutrients called lignans, but whole-grain wheat has three times more, according to Dietary Fiber Food. Lignans are converted into substances that are similar to estrogen. These phytoestrogens are weaker than the body’s natural estrogen, but they bind to the same receptors. If your estrogen levels are low, lignans can increase total levels. If estrogen levels are normal, the weaker phytoestrogens may lower total levels when they bind to the receptors and displace natural estrogen. Diets that include lignan-rich foods are associated with a lower risk of cardiovascular disease and may protect against menopausal symptoms. Wheat bran lignans may slow the spread of cancerous tumors, according to Kansas State University.
Wheat contains gluten but rice doesn’t, which means that there’s no contest between the two if you’re following a gluten-free diet. Gluten is a protein in wheat that causes inflammation of the small intestine in people who have celiac disease or an allergy to wheat. Rice flour is a commonly used substitute for wheat flour in gluten-free products.