Bring Your Own Rice!
When my grandparents came to babysit me, they always brought their own rice. As a member of an Asian family, rice was a staple to our diet; but my parents’ rice was not good enough for my grandparents. They ate brown rice only, because brown rice is, according to my grandfather, “much MUCH healthier.”
I have some concerns about my grandfather’s statement.
First, how do we define “healthy” in this context?
Second, does a simple swap between different types of rice make a difference?
Looking at experimental data that is published comparing brown and white rice, one of the best studies was a prospective cohort study carried out in 2010 (Sun et al., 2010).
How did this study define “healthy?”
The 2010 study assessed the effect of brown and white rice on risk for Type 2 Diabetes.
Does a simple swap make a difference?
According to this study, yes. Results indicate that replacing 50 grams/day of cooked white rice with brown rice is associated with a 16% lower risk of Type 2 Diabetes. This may be because white rice has a higher glycemic index (GI), meaning it produces a higher glucose response compared to a given amount of brown rice. The higher GI may be due to white rice by how white rice is produced; the outer bran and germ portions of brown rice is removed, thus stripping it of many nutrients such as vitamins and fiber.
How Did They Measure This? Intake of white and brown rice was measured using Food Frequency Questionnaires. These questionnaires were measured at baseline and every 4 years from 1986-2000. Participants checked a box whether they ate white or brown rice in <1 serving/ month, 1-3 servings/ month, 1 serving/ week, 2-4 servings/ week, and >5 servings per week.
The strengths of this study: The Study Population and Study Length.
There was a very large study population size used: 39, 765 men and 157, 463 women from three cohorts. The population also hosted a large range of ages - from 26-87 years. Additionally, the study was conducted for 14 years.
However, we must be cautious with the interpretation and take this study with a grain of salt (or, maybe, a grain of rice).
A potential weakness of the study: All subjects used were health professionals which could factor into their overall health. Healthcare professionals are generally more active than the majority of the population (Chan et al., 2018). Their background in physiology and nutrition may also factor into better eating habits, and this population is unlikely to represent the average person.
So, is my grandfather right?
Other studies, such as a prospective cohort study with Chinese women (Villegas et al., 2007), also suggest that brown rice is better for reducing the risk of Type 2 Diabetes, supporting my grandfather. Other support for grandpa includes a cohort study that concluded that glucose and insulin were lower after brown rice ingestion compared with white rice (Shimabukuro et al., 2014). This study found that eating brown rice would improve not only insulin resistance but total cholesterol levels and endothelial function.
However, other studies have found no difference between white and brown rice consumption. One of these studies includes an experimental study conducted in Shanghai (Zhang et al., 2011). After measuring metabolic risk factors such as body mass index (BMI), blood pressure, and glucose concentrations, investigators found no substantial improvement in diabetes and other metabolic diseases in their 202 participants. However, this study was only conducted for 16 weeks, so it may be that longer-term use of brown rice is needed to observe the beneficial effects.
Many studies suggest that there may be something in brown rice that may be healthier; however, more studies with large study populations are needed to understand the benefits of brown rice. In the meantime, I will join my grandfather in eating brown rice with my dinner.
Written by Joanne Newens and edited by Aldrin Gomes
Sun, Q., Spiegelman, D., Van Dam, R. M., Holmes, M. D., Malik, V. S., Willett, W. C., & Hu, F. B. (2010, June 14). White rice, brown rice, and risk of type 2 diabetes in US men and women. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/20548009
Chan, L., McNaughton, H., & Weatherall, M. (2018, March 11). Are physical activity levels of health care professionals consistent with activity guidelines? A prospective cohort study in New Zealand. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5851104/
Villegas, R., Liu S, Gao YT, Yang G, Li H, Zheng W, Shu XO. Prospective study of dietary carbohydrates, glycemic index, glycemic load, and incidence of type 2 diabetes mellitus in middle-aged Chinese women. Arch Intern Med. 2007 Nov 26;167(21):2310–2316.
Shimabukuro, M., Higa, M., Kinjo, R., Yamakawa, K., Tanaka, H., Kozuka, C., Yabiku, K., Taira, Shin-Ichiro, T., Sata, M., Masuzaki, H. (2014, January 28). Effects of the brown rice diet on visceral obesity and endothelial function: The BRAVO study. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/23930929
Zhang, G., Pan, A., Zong, G., Yu, Z., Wu, H., Chen, X., Li, H., Hong, B., Malik, V., Willett, W., Spiegelman, D., Hu, F., Lin, X. (2011, September). Substituting white rice with brown rice for 16 weeks does not substantially affect metabolic risk factors in middle-aged Chinese men and women with diabetes or a high risk for diabetes. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/21795429