Rice is a staple food in most populations in the world.
More than 3.5 billion people around the world eat rice daily and is especially prevalent in Asia, Latin America, and parts of Africa.
Fact: There are more than 120,000 different varieties of rice worldwide (categorised by their length, color, and subspecies).
120,000
known varieties of rice worldwideAnd not all rice varieties are the same in nutritional content, as they can differ significantly.
According to the US National Institutes of Health, studies show a wide variation in anthocyanin, antioxidant, and phenolic compounds across different rice types.
Clinical data is out: white rice intake can significantly increase the "glycaemic load" of consumers and bring some adverse health effects.
White rice, heart disease and diabetes
Some studies indicate that there may be an association between white rice intake and metabolic diseases, including cardiovascular disease (CVD) risks and type 2 diabetes mellitus (T2DM), studies show.
A systematic review of 14 studies which reviewed the correlation between rice intake and CVD saw some of the risk factors it poses.
The “meta-analysis”, published in the PMC PubMed Central in February 2015, found a significant association between white rice consumption and several risk factors of CVD – including type 2 diabetes and metabolic syndrome.
Asians at risk
The impact rice has on your body depends on the type of rice you eat, as well as quantity and frequency.
While “moderate” consumption as part of a balanced diet does not necessarily increase the risk, researchers said high daily intake of white rice has been linked to a higher risk of type 2 diabetes, especially in Asian populations where rice is a dietary staple.
Asians are particularly at risk, according to the study – Chinese and Japanese populations had much higher white rice consumption levels than did Western populations – with an average intake level of three to four servings/day vs one to two servings/week.
Harvard study
A 2012 Harvard study conducted by the Department of Nutrition, titled “White rice consumption and risk of type 2 diabetes: meta-analysis and systematic review” also found that higher consumption of white rice is associated with a significantly increased risk of type 2 diabetes, especially in Asian (Chinese and Japanese) populations.
The research, published in the peer-reviewed BMJ, poured through clinical data of 13,284 incident cases of type 2 diabetes among 352,384 participants with follow-up periods ranging from 4 to 22 years.
The pooled relative risk was 1.55 (with a 95 per cent confidence interval 1.20 to 2.01) comparing the highest with the lowest category of white rice intake in Asian populations, “whereas the corresponding relative risk was 1.12 (0.94 to 1.33) in Western populations (P for interaction=0.038)”.
In the total population, the dose-response meta-analysis indicated that for each serving per day increment of white rice intake, the relative risk of type 2 diabetes was “1.11 (1.08 to 1.14) (P for linear trend<0.001)”.
Association with T2DM
This means: The analysis found a statistically significant association between white rice consumption and an increased risk of type 2 diabetes.
Specifically, every extra daily serving of white rice is linked to an 11 per cent rise in the risk of developing type 2 diabetes.
While the “meta-analyses” showed mixed results regarding the association between rice consumption and chronic diseases, researchers said the risks are also influenced by lifestyle factors, overall dietary patterns, and the type of rice consumed, they pointed out.
The “linear trend” indicates that the relationship between white rice intake and diabetes risk increases consistently (linearly) with each additional serving.
White rice vs brown rice
Here's the thing about white rice: it is considered a refined grain because it doesn’t have any bran. It doesn’t pack a lot of macro- and micro-nutrients other than carbohydrates. Researchers point out that eating too much of it might starve your body of important nutrients.
That’s because all rice is carbohydrate-rich and can fill you up quickly, which could leave little room for proteins and fat.
Some studies have found that brown rice consumption is associated with a lower risk of type 2 diabetes. Other studies have found that replacing white rice with brown rice improved HDL-C and reduced DBP in middle-aged Chinese men and women.
Eating brown rice daily also means getting more iron, magnesium, and B vitamins, which are vital for a strong immune system.
Whole grains: The US dietary guidelines recommend consuming at least 3-ounce equivalents of whole grains per day. Whole grain rice contains the pericarp, aleurone, and germ, and plays a role in preventing cardiovascular risk factor.
Brown rice (BR), in particular, has gained popularity for its nutritional advantages over white rice.
Moreover, replacing white with brown rice (50 grams/day) reduced T2DM risk by 16 per cent, and substituting beans for white rice reduced the odds of metabolic syndrome by 35 per cent, according a 2010 research published in the JAMA Internal Medicine (Sun Q, et al. “White rice, brown rice, and risk of type 2 diabetes in US men and women”).
The conclusion made by Sun's team came following a 16-week randomised trial of replacing white with brown rice in middle-aged Chinese men and women with or at high risk for T2DM, which improved HDL-C and reduced diastolic blood pressure (DBP) in the brown rice group.
What it measures: The GI compares how a food's carbohydrates increase blood sugar levels to a reference food, usually glucose, which has a GI of 100.
How it's used: The GI can help you manage your diabetes or follow a low-glycemic diet.
Glycaemic index
Data from the international Prospective Urban and Rural Epidemiological Study (PURE; 138,926 individuals in 628 communities, 17 countries) suggested that “whole grain and cereal fiber consumption, while decreasing total and high-glycaemic index (GI) carbohydrate, are helpful strategies to prevent T2DM and CVD in the general population”.
Furthermore, low-glycemic index diets improve glycemic control and serum lipids in RCTs of participants with T2DM with major implications for CHD risk reduction in this vulnerable segment of the population whose numbers are increasing rapidly globally.
Debate over white rice
The debate rages on. A 2023 study published in the journal “Critical Reviews in Food Science and Nutrition” stated that the quality of evidence implicating white rice in adverse health outcomes remains unclear.
To evaluate the association between white rice consumption and the risk of cardiometabolic and cancer outcomes, a team led by
Honghao Lai of the Evidence-Based Social Science Research Center, School of Public Health, Lanzhou University in China conducted a systematic review and dose-response meta-analysis of the relevant publications.
Twenty-three articles including 28 unique prospective cohorts with 1,527,198 participants proved eligible after a comprehensive search in four databases.
For the risk of type 2 diabetes mellitus (T2DM), the pooled RR was 1.18 (16 more per 1,000 persons) for comparing the highest with the lowest category of white rice intake, with moderate certainty evidence.
Females presented a higher risk (23 more per 1,000 persons) in subgroup analysis.
The researchers, however, found that every additional 150 grams of white rice intake per day was associated with a 6 per cent greater risk of T2DM (5 more per 1,000 persons) with a linear positive trend.
“We found no significant associations between white rice intake and risk of cardiovascular diseases (CVD), CVD mortality, cancer, and metabolic syndrome.”
The researchers concluded that there was a “moderate-certainty evidence” showing that white rice intake was associated with T2DM risk, with a linear positive trend.
However, they stated there’s a “low to very low certainty of evidence” suggesting that no substantial associations were found between white rice intake and other cardio-metabolic and cancer outcomes. The Lanzhou researchers stated that more cohorts are needed to strengthen their evidence.
Takeaways
- The key when it comes to consuming rice (especially white rice): moderation.
- Making brown rice a part of your daily diet may mean you are consuming greater amounts of fibre, which helps lower your overall cholesterol levels and makes you feel fuller and longer.
- Choosing whole grain rice options and incorporating them into a varied diet may help maximise health benefits and reduce potential risks.
