White and Brown Rice
- More than 80 years after Christian Eijkman was awarded the Nobel price for demonstrating the dangers of white rice, it continues to be used in large quantities worldwide. However, the focus has shifted from beriberi to diabetes, affecting millions of people especially the rice loving populations like south Indians.
- Polished rice was served to army officers while cheap unpolished brown rice was given to the enlisted servicemen and chickens. A cook inadvertently gave the polished rice to chickens which resulted in the beriberi epidemic 3 weeks later and was cured when another cook tried to save money by feeding the chickens with unpolished rice. Christian Eijkman was awarded Nobel prize in 1929 for identifying white rice as the cause and brown rice as the cure of beriberi, which was killing millions and millions of chickens in 1889.
- Eijkman did experiments on prisoners and produced and cured beriberi by alternatively feeding them polished rice and unpolished rice. Casimir Funk later identified thiamin as the factor in unpolished rice that protected against beriberi.
- Rice has been the staple food in Asian countries for millennia. By the 20th century, advances in grain processing technology made large scale production of refined grains possible. During the refining process of brown rice, almost all the bran and some of the germ of the intact rice grains are removed to produce white rice that primarily consists of starchy endosperm.1
- Other consequences of refining include loss of fiber, vitamins especially thiamin, magnesium and other minerals, phytoestrogens, and phytic acid; many of which have protective effect on diabetes.1
- The commercial milling process produce disruptions in the physical and botanical structure of rice resulting in higher glycemic index (the blood sugar spike following a meal) for white rice. The glycemic index is 64 for white rice compared to 55 for brown rice. A higher dietary glycemic index is consistently associated with diabetes.1
- Brown rice is unrefined whole grain and is produced by removing the outermost layers containing the germ and bran, which are rich in nutrients including dietary fiber, vitamins, minerals, and other unmeasured dietary constituents.
- Brown rice consumption may impart beneficial effects on diabetes by virtue of its high content of multiple nutrients such as fiber, vitamins, and minerals that are lost during refining and milling processes, whereas white rice consumption has many detrimental effects.1
- Consuming whole grains, especially substitution of brown rice for white can reduce the risk of diabetes, according to an analysis of nearly 200,000 adults enrolled in three prospective cohorts in the US.1
- White rice consumption is associated with the risk of developing diabetes in diverse populations.1-4 Replacing 50 g/day of white rice in the diet with the same amount of brown rice is estimated to lower the risk of diabetes by 16% whereas replacing it with whole grains as a group is estimated to reduce the risk of diabetes by 36%.1
- White rice accounts for 54% of daily energy consumption in China compared to <2% in the US. Among Chinese, white rice represents 70% of the glycemic load, among whom consumption of 300 g/d of white rice (2 serving/d) compared to <200 g/d is associated with 78% higher risk of diabetes. 5
- White rice may account for more than 60% of the energy consumption in South India where the consumption is nearly double that of the Chinese and 12 to 20 times higher than in the USA. For example people in the highest quartile consumed about 516 g/d of rice compared with 320 g/d by those in the lowest quartile.3
- As the amount of rice consumption increased, the consumption of other food items, like fruits and vegetables, legumes, and dairy products become less and less. For instance, in the lowest quartile that consumed less rice, the intake of fruits was about 300 g/d, while fruit consumption in the highest quartile was 233 g/d. The same trend was observed in the case of other food items.
- The carbohydrate derived from polished white rice is 66% of the total carbohydrate intake. Both glycemic load and white rice was associated with 4-5-fold increase in the risk of diabetes in South India.3
- Rice consumption in the US has increased 4-fold from 5 to 20 lbs per year between 1930 and 2010; white rice accounts for 70% of rice consumption. This corresponds to 25 g/d of rice and 18 g/d of white rice. Yet, only 1-2% of Americans consume 5 or more servings of rice per week (107 g/d).
- Given the increased risk of white rice, replacement of one serving of (150 g of cooked) white rice with same amount of brown rice can reduce the risk of diabetes by 48%, whereas the same replacement with whole grains as a group can reduce the risk by 108%.1
- The high consumption of white rice is also very common in Korea where most of the people, including diabetic subjects, consume a large bowl (380mL) of rice. Switching to a small bowl (200mL) was associated with significant reduction in energy intake, carbohydrate intake, and resulted in lower blood sugar levels. This appears to be a sensible and readily applicable strategy for all rice eating populations to reduce the consumption of rice, especially those with diabetes.4
- Most people who habitually consume white rice are unaware of the harmful effects of white rice and the health benefits of brown rice. With proper education, encouragement, and possibly better pricing, many people could be persuaded to switch to brown rice with all its health benefits.6
1. What is the glycemic index of rice?
Glycemic index of rice varieties have ranged from as low as 48 for the Australian Doongara white rice variety to 109 for Thailand Jasmine polished white long grain rice.7 Three commonly used polished raw rice (non-parboiled) varieties in South India, exhibited high glycemic indices (>70) values (Surti Kolam-77; followed by Sona Masuri-72; and Ponni (70). Fiber -rich accompaniments such as pulses and legumes and green leafy vegetables could possibly help to lower the overall meal of rice.
2. What is the glycemic load of rice?
Rice being a staple food is consumed in considerably large quantities in South Asia accounting for as high as 50-60% of the daily calories, resulting in high glycemic load. Most South Indians consume four to five cups of rice for lunch and dinner and even breakfast. Such high glycemic load and glycemic index staple diets may further aggravate the features of the Asian Indian Phenotype. Awareness about the nutritive properties of brown rice was poor and was cited as a major barrier to its acceptance.8
1. Sun Q, Spiegelman D, van Dam RM, et al. White rice, brown rice, and risk of type 2 diabetes in US men and women. Arch Intern Med. Jun 14 2010;170(11):961-969.
2. Nanri A, Mizoue T, Noda M, et al. Rice intake and type 2 diabetes in Japanese men and women: the Japan Public Health Center-based Prospective Study. Am J Clin Nutr. Dec 2010;92(6):1468-1477.
3. Mohan V, Radhika G, Sathya RM, Tamil SR, Ganesan A, Sudha V. Dietary carbohydrates, glycaemic load, food groups and newly detected type 2 diabetes among urban Asian Indian population in Chennai, India (Chennai Urban Rural Epidemiology Study 59). The British journal of nutrition. Jul 9 2009:1-9.
4. Ahn HJ, Han KA, Kwon HR, Min KW. The Small Rice Bowl-Based Meal Plan was Effective at Reducing Dietary Energy Intake, Body Weight, and Blood Glucose Levels in Korean Women with Type 2 Diabetes Mellitus. Korean Diabetes J. Dec 2010;34(6):340-349.
5. Villegas R, Liu S, Gao YT, et al. Prospective study of dietary carbohydrates, glycemic index, glycemic load, and incidence of type 2 diabetes mellitus in middle-aged Chinese women. Arch Intern Med. Nov 26 2007;167(21):2310-2316.
6. Zhang G, Malik VS, Pan A, et al. Substituting brown rice for white rice to lower diabetes risk: a focus-group study in Chinese adults. J Am Diet Assoc. Aug 2010;110(8):1216-1221.
7. Atkinson FS, Foster-Powell K, Brand-Miller JC. International tables of glycemic index and glycemic load values: 2008. Diabetes Care. Dec 2008;31(12):2281-2283.
8. Kumar S, Mohanraj R, Sudha V, et al. Perceptions about varieties of brown rice: a qualitative study from Southern India. J Am Diet Assoc. Oct 2011;111(10):1517-1522.