To Americans, rice is the most familiar food eaten in grain form. It is commonly served as a side dish in American households, but elsewhere it forms the basis for most meals. In fact, half the world's peoples eat rice as their stable food. In some languages, the word for "eat" means, "eat rice."
In general, rice is a good source of B vitamins, such as thiamin and niacin, and also provides iron, phosphorus, and magnesium. Although rice is lower in protein than other cereal grains, its protein quality is good because it contains relatively high levels of the amino acid lysine.
Unfortunately, this important food source is usually eaten in most parts of the world in its least nourishing form – that is, milled and polished to remove the bran and germ, which contain valuable nutrients. In the United States, white rice – as this refined form is called – is enriched with two B vitamins – thiamin and niacin – and iron. But in many countries where it constitutes the bulk of the diet, enrichment is not a common practice.
When rice is milled and polished the bran portion of the grain is removed. Like oat bran, rice bran is enjoying a reputation as a cholesterol fighter. Researchers at the USDA have found that rice bran lowers blood cholesterol in animals just as much as oat bran. But nutritionists are interested in more than the fiber content of rice.
Because of the composition of the rice kernel and the way it is milled, the processed bran ends up containing rice germ, which is rich in oil. Scientists in Japan and India have found that this highly unsaturated oil also has a substantial cholesterol-lowering effect. Although brown rice is exceedingly nutritious, it is not a concentrated source of oil.
Brown rice has had only its husk removed during milling. With the bran intact, it retains more fiber, folacin, iron, riboflavin, potassium, phosphorus, zinc, and trace minerals such as copper and manganese, than other types of rice. Moreover, brown rice is the only form of the grain that contains vitamin E.
Although it is known that brown rice has a higher nutritional value when compared to the milled and polished rice (white rice) before consumption, researchers still investigate the nutritional value to humans after consumption of these two forms of rice. Scientific research has taken its investigation into many different areas of the nutritional value of brown compared to "white" rice. These include, 1) Glycemic index, 2) nutrient value, 3) disease prevention, 4) Vitamin B12 levels, 5) digestibility of proteins, and 6) effect of rice fiber in the intestinal tract. The reader is invited to review each of the following areas of research and references to further understand the impact and nutritional value that the natural unprocessed rice compared to processed rice has on the human body.
Glycemic Index
The relative rate at which glucose appears in the blood after the ingestion of various sources of carbohydrate is measured by the glycemic index of a food compared with white bread with a glycemic index of 100. This value is especially important to persons with diabetes.
Rice has given a wide range of results in glycemic index (GI) studies around the world. The GI of white rice has ranged from as low as 54 to as high as 121. In a study by Miller JB, et. al., the glycemic index and the insulin response of various foods were tested and compared. While the GI of the white and brown rice were similar the insulin response for brown rice was significantly lower than for white rice. These findings in this study also raise questions about the value of the GI alone without knowledge of the insulin response to foods. (1)
Nutritional Value
Cereals are considered an important source of nutrients both in human and animal nourishment. Because of the concern that nutrients are removed in the processing of rice, various studies have been conducted to determine the actual bioavailability of the nutrients after consumption. In a study by Calegare M da D and Tirapequi J, experimental data did not provide evidence that the brown rice diet was better than the diet based on white rice in relation to nutrients. However, in a study by Rensburg SJ, et. al., the effects of various dietary staples on esophageal carcinogenesis was investigated. (2, 3)
Rensburg noted that epidemiological studies associated large differences of esophageal cancer risk with the nature of the staple diet. It was apparent that a greater geographic variation for the incidence of esophageal carcinoma than for any other cancers would provide clues to causation.
The conclusion from this study suggested that when a diet low in micronutrients is used habitually, whether in Africa, China, the Middle East, or in the United States, the risk for esophageal cancer is generally at least 20 to 25 male cases per 100,000 per year, as opposed to a risk some 50 times lower in equally deprived people not using primarily modern types of corn, wheat, or polished rice.
Protein Digestibility
Some studies have compared the digestibility of proteins with the consumption of white rice and brown rice. In a study by Miyoshi H, et. al., where there was a low protein intake, the brown rice did affect protein metabolism (4). However, in a study by Bradbury HJ, et al. it was concluded that the protein digestibility of cooked brown rice was approximately the same as that of cooked milled rice, hence it is advantageous for those for whom rice is a staple food to consume brown rather than milled rice. (5)
Microflora
Recently, there has been a great interest in dietary fiber as a possible protection against several colonic disorders including diverticular disease, cancer, and constipation. The fermentation of dietary fiber in human intestines is well established. Since brown rice contains higher contents of dietary fiber than the polished rice, it is of interest to determine what effects, if any, rice fiber exerts on the human fecal microflora.
The effects of brown rice, containing fourfold as much dietary fiber as polished rice, were determined in a study by Benno Y, et. al. It was determined that there was significantly increased numbers of beneficial bacteria (probiotics) during the brown rice intake, whereas the total counts of harmful bacteria during the intake of brown rice were lower than those before and after the intake .(6)
Dr. Khem Shahani, who has written over 200 papers on the beneficial bacteria, has repeatedly emphasized the importance of maintaining a balance of the beneficial bacteria in the intestinal tract. There are significant studies that should alert us to the dangers to our health of these harmful bacteria, when through our diet, drugs, and other means, these beneficial bacteria are depleted from our intestinal tract.
In Conclusion
When you weigh the differences of White rice to Brown rice the health benefits are extremely in the favor of brown rice for these reasons. When rice is milled and polished the bran portion of the grain is removed.
Researchers at the USDA have found that rice bran lowers blood cholesterol in animals just as much as oat bran. Moreover, brown rice is the only form of the grain that contains vitamin E.
Cancer risk is some 50 times lower in equally deprived people not using primarily modern types of corn, wheat, or polished rice.
Brown rice has a higher nutritional value when compared to the milled and polished rice (white rice). While the GI of the white and brown rice were similar the insulin response for brown rice was significantly lower than for white rice.
It was determined that there was significantly increased numbers of beneficial bacteria (probiotics) during the brown rice intake, whereas the total counts of harmful bacteria during the intake of brown rice were lower than those before and after the intake.
The bottom line is this: Whenever you take a natural food from nature and change its composition or strip nutrients from it, you will always have less human nutritional benefits. Just another lesson that Mother Nature knows best.
References:
1. Miller JB, et. al. Rice: a high or low glycemic food? Am J Clin Nutr 1992;56:1034-6.
2. Callegaro M da D, et. al. Comparison of the nutritional value between brown rice and white rice. Arq Castroenterol. 1996;33(4):225-31.
3. Schalk J van R, et. al. Effects of various dietary staples on esophageal carcinogenesis induced in rats by subcutaneously administered N-nitrosomethylbenzylamine. J. of National Cancer Inst. 1985;75:561-566.
4. Miyoshi H, et. al. Effects of brown rice on apparent digestibility and balance of nutrients in young men on low protein diets. J. Nutr. Sci. Vitaminol. 1987;33:207-218.
5. Bradbury HJ, et. al. Digestibility of proteins of the histological components of cooked and raw rice. British J. of Nutr. 1984;52:507-513.
6. Benno Y, et. al. Effect of rice fiber on human fecal microflora. Microbiol. Immunol. 1989;33(5):435-40.
In general, rice is a good source of B vitamins, such as thiamin and niacin, and also provides iron, phosphorus, and magnesium. Although rice is lower in protein than other cereal grains, its protein quality is good because it contains relatively high levels of the amino acid lysine.
Unfortunately, this important food source is usually eaten in most parts of the world in its least nourishing form – that is, milled and polished to remove the bran and germ, which contain valuable nutrients. In the United States, white rice – as this refined form is called – is enriched with two B vitamins – thiamin and niacin – and iron. But in many countries where it constitutes the bulk of the diet, enrichment is not a common practice.
When rice is milled and polished the bran portion of the grain is removed. Like oat bran, rice bran is enjoying a reputation as a cholesterol fighter. Researchers at the USDA have found that rice bran lowers blood cholesterol in animals just as much as oat bran. But nutritionists are interested in more than the fiber content of rice.
Because of the composition of the rice kernel and the way it is milled, the processed bran ends up containing rice germ, which is rich in oil. Scientists in Japan and India have found that this highly unsaturated oil also has a substantial cholesterol-lowering effect. Although brown rice is exceedingly nutritious, it is not a concentrated source of oil.
Brown rice has had only its husk removed during milling. With the bran intact, it retains more fiber, folacin, iron, riboflavin, potassium, phosphorus, zinc, and trace minerals such as copper and manganese, than other types of rice. Moreover, brown rice is the only form of the grain that contains vitamin E.
Although it is known that brown rice has a higher nutritional value when compared to the milled and polished rice (white rice) before consumption, researchers still investigate the nutritional value to humans after consumption of these two forms of rice. Scientific research has taken its investigation into many different areas of the nutritional value of brown compared to "white" rice. These include, 1) Glycemic index, 2) nutrient value, 3) disease prevention, 4) Vitamin B12 levels, 5) digestibility of proteins, and 6) effect of rice fiber in the intestinal tract. The reader is invited to review each of the following areas of research and references to further understand the impact and nutritional value that the natural unprocessed rice compared to processed rice has on the human body.
Glycemic Index
The relative rate at which glucose appears in the blood after the ingestion of various sources of carbohydrate is measured by the glycemic index of a food compared with white bread with a glycemic index of 100. This value is especially important to persons with diabetes.
Rice has given a wide range of results in glycemic index (GI) studies around the world. The GI of white rice has ranged from as low as 54 to as high as 121. In a study by Miller JB, et. al., the glycemic index and the insulin response of various foods were tested and compared. While the GI of the white and brown rice were similar the insulin response for brown rice was significantly lower than for white rice. These findings in this study also raise questions about the value of the GI alone without knowledge of the insulin response to foods. (1)
Nutritional Value
Cereals are considered an important source of nutrients both in human and animal nourishment. Because of the concern that nutrients are removed in the processing of rice, various studies have been conducted to determine the actual bioavailability of the nutrients after consumption. In a study by Calegare M da D and Tirapequi J, experimental data did not provide evidence that the brown rice diet was better than the diet based on white rice in relation to nutrients. However, in a study by Rensburg SJ, et. al., the effects of various dietary staples on esophageal carcinogenesis was investigated. (2, 3)
Rensburg noted that epidemiological studies associated large differences of esophageal cancer risk with the nature of the staple diet. It was apparent that a greater geographic variation for the incidence of esophageal carcinoma than for any other cancers would provide clues to causation.
The conclusion from this study suggested that when a diet low in micronutrients is used habitually, whether in Africa, China, the Middle East, or in the United States, the risk for esophageal cancer is generally at least 20 to 25 male cases per 100,000 per year, as opposed to a risk some 50 times lower in equally deprived people not using primarily modern types of corn, wheat, or polished rice.
Protein Digestibility
Some studies have compared the digestibility of proteins with the consumption of white rice and brown rice. In a study by Miyoshi H, et. al., where there was a low protein intake, the brown rice did affect protein metabolism (4). However, in a study by Bradbury HJ, et al. it was concluded that the protein digestibility of cooked brown rice was approximately the same as that of cooked milled rice, hence it is advantageous for those for whom rice is a staple food to consume brown rather than milled rice. (5)
Microflora
Recently, there has been a great interest in dietary fiber as a possible protection against several colonic disorders including diverticular disease, cancer, and constipation. The fermentation of dietary fiber in human intestines is well established. Since brown rice contains higher contents of dietary fiber than the polished rice, it is of interest to determine what effects, if any, rice fiber exerts on the human fecal microflora.
The effects of brown rice, containing fourfold as much dietary fiber as polished rice, were determined in a study by Benno Y, et. al. It was determined that there was significantly increased numbers of beneficial bacteria (probiotics) during the brown rice intake, whereas the total counts of harmful bacteria during the intake of brown rice were lower than those before and after the intake .(6)
Dr. Khem Shahani, who has written over 200 papers on the beneficial bacteria, has repeatedly emphasized the importance of maintaining a balance of the beneficial bacteria in the intestinal tract. There are significant studies that should alert us to the dangers to our health of these harmful bacteria, when through our diet, drugs, and other means, these beneficial bacteria are depleted from our intestinal tract.
In Conclusion
When you weigh the differences of White rice to Brown rice the health benefits are extremely in the favor of brown rice for these reasons. When rice is milled and polished the bran portion of the grain is removed.
Researchers at the USDA have found that rice bran lowers blood cholesterol in animals just as much as oat bran. Moreover, brown rice is the only form of the grain that contains vitamin E.
Cancer risk is some 50 times lower in equally deprived people not using primarily modern types of corn, wheat, or polished rice.
Brown rice has a higher nutritional value when compared to the milled and polished rice (white rice). While the GI of the white and brown rice were similar the insulin response for brown rice was significantly lower than for white rice.
It was determined that there was significantly increased numbers of beneficial bacteria (probiotics) during the brown rice intake, whereas the total counts of harmful bacteria during the intake of brown rice were lower than those before and after the intake.
The bottom line is this: Whenever you take a natural food from nature and change its composition or strip nutrients from it, you will always have less human nutritional benefits. Just another lesson that Mother Nature knows best.
References:
1. Miller JB, et. al. Rice: a high or low glycemic food? Am J Clin Nutr 1992;56:1034-6.
2. Callegaro M da D, et. al. Comparison of the nutritional value between brown rice and white rice. Arq Castroenterol. 1996;33(4):225-31.
3. Schalk J van R, et. al. Effects of various dietary staples on esophageal carcinogenesis induced in rats by subcutaneously administered N-nitrosomethylbenzylamine. J. of National Cancer Inst. 1985;75:561-566.
4. Miyoshi H, et. al. Effects of brown rice on apparent digestibility and balance of nutrients in young men on low protein diets. J. Nutr. Sci. Vitaminol. 1987;33:207-218.
5. Bradbury HJ, et. al. Digestibility of proteins of the histological components of cooked and raw rice. British J. of Nutr. 1984;52:507-513.
6. Benno Y, et. al. Effect of rice fiber on human fecal microflora. Microbiol. Immunol. 1989;33(5):435-40.
