It Is Hard To Ignore The Link Between White Rice and Type 2 Diabetes

There is a growing Type 2 Diabetes (T2D) epidemic in Asia and increasing levels of the condition in Africa, the Middle East and Pacific island countries. The growth of T2D cases is linked to high rates of white rice consumption.

Studies have linked white rice consumption with high glycemic (High-GL) indexes. Asia has the highest per capita rice consumption followed by Africa, the Middle East and Pacific island nations. Incidents of T2D are on the rise in all with the common link a diet of white rice, the food staple often served three times daily.

Is white rice truly the cause or could there be other explanations?

Studies of causal variants for T2D point to factors such as body fat to body mass ratios. In the United States, 34 million Americans have diabetes with more than 90% having T2D. T2D usually develops in adults over 45. It is linked to inactivity and obesity. It is also linked to diet and lifestyle choices. Exercise and dieting are seen as preventatives.

T2D can run in families? Is this genetics at work or is the cause epigenetic such as shared lifestyles and eating habits?

Scientists say it could be both pointing to 13 genes associated with T2D. Some of these impair insulin production. Some regulate glucose. Some regulate fat cell differentiation. The one most associated with T2D is TCF7L2 (Transcription Factor 7-Like 2), a protein-coding gene that is consistently replicated across diverse population groups.

TCF7L2 influences sulfonylurea, an oral hypoglycemic agent that affects the production of the incretin hormone GLP-1, the Glucagon-like peptide-1 which influences insulin secretion from the pancreas and inhibits glucagon release to lower blood sugar levels after meals. You may recently have become familiar with GLP-1 since it is the highly touted active ingredient in Ozempic and other semaglutide drugs that are all the rage these days for those trying to lose weight.

What role does genetics play in the occurrence of T2D? Besides lacking a key protein or a misfiring gene, a person with one parent with T2D is 40% at risk over his or her lifetime of getting it. Where both parents have T2D, the lifetime risk rises to 70%. If your sibling has T2D, you are three times more likely at risk.

Big white rice eaters in Asia, Africa, the Middle East and the Pacific island nations, however, because of their fondness for this staple in their diets is seen as the biggest trigger in the growing T2D epidemic with 537 million in 2021 reported to be suffering from the disease.

A solution to this white rice dietary intake is a replacement, a Low-GI rice. GI refers to the glycemic index, a scale used to measure sugar levels in carbohydrate-containing foods. The scale goes from 0 to 100 with anything low below 55. High is above 70. The GI rating comes from measuring blood glucose levels after a person consumes food with 50 grams of carbohydrates following a 12-hour fast. Foods with high GI levels release glucose quickly causing blood sugar spikes. Foods with low GI levels break down slowly during digestion and produce lower GIs.

A recent study in Trends in Plant Science reviewed the potential of replacing existing white rice varieties with Low-GI rice. It noted if 25% of the population were to switch to a Low-GI rice variety, T2D rates in Asia and elsewhere could fall dramatically.

Another study published in the British Medical Journal noted that a large bowl of white rice eaten daily increased the risk of T2D by 10%. Consuming 5 or more servings of white rice per week raised that risk by 17%.

The work by those doing rice research at the Max Planck Institute in Germany has focused on developing Low-GI rice strains. Testing 380 seed samples has led to identifying a strain with a GI as low as 25 compared to 70 to 72 in most other rice varieties. Getting this new Low-GI rice to rice eaters, however, comes with challenges.

Consider the story of the effort to introduce fortified golden rice into Asian and African diets. Golden rice is a variety that is fortified with vitamin A. Vitamin A deficiency causes blindness in children and is the leading cause of preventable childhood blindness. It affects one-third of children between the ages of 6 and 59 months globally. The highest rates are in sub-Saharan Africa at 48% and South Asia at 44%. Vitamin A-rich golden rice if introduced into the diet once a day would eliminate the child blindness risk, yet the countries of these regions have largely been resistant to introducing it.

That’s why the Max Planck scientists face an uphill battle. They need their rice to be the same colour and texture as white rice. So far, however, the first-generation Low-GI rice may be the same colour but it is firmer than commonly eaten white rice. The scientists are in a race to improve their Low-GI rice’s texture noting that battling T2D makes the effort worthwhile. The Max Planck researchers are not stopping at white rice. They are also looking at other starchy staples such as wheat and tubers (potatoes, yams, sweet potatoes, and cassava) to develop Low-GI strains to improve global health through diet.