29th March 2021, Dr Chee L Khoo
463 million adults are living with diabetes globally, and this number is estimated to rise to 700 million by 2045. Interestingly, 60% of them live in Asia. By 2030, without intervention, both China and India combined will have almost half a billion of people with diabetics. While lifestyle issues and epigenetics play significant roles in the ever increasing prevalence of type 2 diabetes (T2D), white rice feature prominently in the Asian diet. White rice, an important staple food in Asian countries for thousands of years, has been shown to have a high glycaemic index. Is there an association between consumption of white rice and a higher risk of T2D?
Now, we are not talking about white rice in patients with known T2D. We are talking about the association between white rice consumption and the risk of developing T2D. White rice has a high glyacemic index, which is higher than that of whole grains such as brown rice, whole wheat, and barley. In addition, white rice loses multiple beneficial nutrients during the refining process, such as fibre and magnesium, which have been shown to be associated with lower T2D risks (1). In addition, people with a higher rice intake may have lower intakes of other foods.
A few prospective studies in different populations have assessed the association between white rice intake and T2D risk, but the results are inconsistent (2–10]:
- Golozar A et al (Iran) – In two prospective population-based cohort studies comparing rice intake in rural and urban areas in Iran, they observed an association between white rice intake and T2DM only in urban areas. While we detected a significant doubling of incidence of diabetes in those with white rice intake more than 250 grams/day in TLGS, in Tehran, we did not observe a significant association in the GCS, in Golestan. The observed association in TLGS was more pronounced in men.
- Hodge AM (Australia) – High dietary GI and intake of white bread and starch were associated with increased risk of type 2 diabetes, while risk was lower with higher intake of sugars, magnesium, and total carbohydrate. These associations were weakened after adjustment for measures of obesity. Intake of fiber was not associated with diabetes.
- Nanri A et al. (Japan) – Elevated intake of white rice is associated with an increased risk of type 2 diabetes in Japanese women. The finding that is suggestive of a positive association of rice intake in physically inactive men deserves further investigation.
- Seah J et al (Singapore) – Higher rice consumption was not substantially associated with a higher risk of T2D in this Chinese population. Recommendations to reduce high white rice consumption in Asian populations for the prevention of T2D may only be effective if substitute foods are considered carefully.
- Soriguer et al (Spain) – A negative association was found between white rice intake in the way it is consumed in Southern Spain, and the 6 years incidence of diabetes.
- Sun Q et al (US) – higher intake of white rice (≥5 servings per week vs <1 per month) was associated with a higher risk of type 2 diabetes. In contrast, high brown rice intake (≥2 servings per week vs <1 per month) was associated with a lower risk of type 2 diabetes.
- Villegas R et al (Shanghai) – Dietary carbohydrate intake and consumption of rice were positively associated with risk of developing type 2 diabetes mellitus.
- Bhavadharini B et al (multiple countries) – Higher consumption of white rice is associated with an increased risk of incident diabetes with the strongest association being observed in South Asia, while in other regions, a modest, nonsignificant association was seen.
Three meta-analyses published in 2012, 2013, and 2015 looked at this association and reached inconsistent results (11-13). A most recent meta-analysis included more studies since 2015 and concluded that a positive association exist between rice intake and incident T2D in Asian populations was found, especially among women (14).
As you can see, the association is not that clear cut. People with a higher rice intake may have lower intakes of other foods. A prospective study has found that participants with a high rice consumption have a different dietary pattern than others with a low rice consumption, as exemplified by lower intakes of foods linked with a lower risk of T2D (6). The mechanism behind the observed sex interaction is not clear yet. Perhaps, men may have a higher muscle content than women, which can metabolise a proportion of glucose and counterbalance the increased glucose levels caused by the intake of white rice. Why do we see a stronger association in Asian countries but less so in European countries?
To further complicate the issue, a large-scale prospective study has shown that the substitution of white rice with noodles, red meat, or poultry is associated with a higher T2D risk while replacing it with whole-grain bread is associated with a lower T2D risk (6).
The potential association between the consumption of white rice and the risk of developing T2D has massive public health implications. T2D can be preventable by diet and lifestyle modification and reducing white rice consumption can be helpful with that effort. However, when decreasing the consumption of white rice, one should pay attention to the replacement food.
- Schulze MB, Schulz M, Heidemann C, Schienkiewitz A, Hoffmann K, Boeing H. Fiber and magnesium intake and incidence of type 2 diabetes: a prospective study and metaanalysis. Arch Intern Med 2007;167:956–65.
- Golozar A, Khalili D, Etemadi A, Poustchi H, Fazeltabar A, Hosseini F, Kamangar F, Khoshnia M, Islami F, Hadaegh F, Brennan P, Boffetta P, Abnet CC, Dawsey SM, Azizi F, Malekzadeh R, Danaei G. White rice intake and incidence of type-2 diabetes: analysis of two prospective cohort studies from Iran. BMC Public Health 2017;17(1):133. https://doi.org/10.1186/s12889-016-3999-4.
- Hirata A, Ohnaka K, Tashiro N,Wang Z, Kohno M, Kiyohara C, et al. Effect modification of green tea on the association between rice intake and the risk of diabetes mellitus: a prospective study in Japanese men and women. Asia Pac J Clin Nutr 2017;26:545–55.
- Hodge AM, English DR, O’Dea K, Giles GG. Glycemic index and dietary fiber and the risk of type 2 diabetes. Diabetes Care 2004;27(11):2701–6. https://doi.org/10.2337/diacare.27.11.2701.
- Nanri A, Mizoue T, Noda M, Takahashi Y, Kato M, Inoue M, Tsugane S. Rice intake and type 2 diabetes in Japanese men and women: the Japan Public Health Center-based Prospective Study. Am J Clin Nutr 2010;92(6):1468–77. https://doi.org/10.3945/ajcn.2010.29512.
- Seah JYH, Koh W-P, Yuan J-M, van Dam RM. Rice intake and risk of type 2 diabetes: the Singapore Chinese Health Study. Eur J Nutr 2019;58(8):3349–60. https://doi.org/10.1007/s00394-018-1879-7.
- Soriguer F, Colomo N, Olveira G, Garcı´a-Fuentes E, Esteva I, Ruiz de Adana MS, Morcillo S, Porras N, Valde´s S, Rojo-Martı´nez G. White rice consumption and risk of type 2 diabetes. Clinical Nutrition 2013;32(3):481–4. https://doi.org/10.1016/j.clnu.2012.11.008.
- Sun Q, Spiegelman D, van Dam RM, Holmes MD, Malik VS, Willett WC, et al. White rice, brown rice, and risk of type 2 diabetes in US men and women. Arch Intern Med 2010;170:961–9.
- Villegas R, Liu S, Gao Y-T, 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;167 (21):2310. https://doi.org/10.1001/archinte.167.21.2310.
- Bhavadharini B, Mohan V, Dehghan M, Rangarajan S, Swaminathan S, Rosengren A, Wielgosz A, Avezum A, Lopez-Jaramillo P, Lanas F, Dans AL, Yeates K, Poirier P, Chifamba J, Alhabib KF, Mohammadifard N, Zaton´ ska K, Khatib R, Vural Keskinler M, Wei Li, Wang C, Liu X, Iqbal R, Yusuf R,Wentzel-Viljoen E, Yusufali A, Diaz R, Keat NK, Lakshmi PVM, Ismail N, Gupta R, Palileo-Villanueva LM, Sheridan P, Mente A, Yusuf S. White rice intake and incident diabetes: a study of 132,373 participants in 21 countries. Dia Care 2020;43(11):2643–50. https://doi.org/10.2337/dc19-2335.
- 4. Hu EA, Pan A, Malik V, Sun Q. White rice consumption and risk of type 2 diabetes: meta-analysis and systematic review. BMJ (Clinical research ed) 2012;344:e1454. https://doi.org/10.1136/bmj.e1454.
- Aune D, Norat T, Romundstad P, Vatten LJ. Whole grain and refined grain consumption and the risk of type 2 diabetes: a systematic review and dose–response meta-analysis of cohort studies. Eur J Epidemiol 2013;28(11):845–58. https://doi.org/10.1007/s10654-013-9852-5.
- Krittanawong C, Tunhasiriwet A, Zhang HongJu, Prokop LJ, Chirapongsathorn S, Sun T, Wang Z. Is white rice consumption a risk for metabolic and cardiovascular outcomes? A systematic review and meta-analysis. Heart Asia 2017;9(2)
- Ren G, Qi J, Zou Y. Association between intake of white rice and incident type 2 diabetes – An updated meta-analysis. Diabetes Res Clin Pract. 2021 Feb;172:108651. doi: 10.1016/j.diabres.2021.108651. Epub 2021 Jan 7. PMID: 33422584.