Is Rice Good For Diabetics?

Some rice grainsRice has received some negative publicity lately regarding its effects on the development of diabetes. A large study, published this March in the British Medical Journal, found that regular eaters of white rice were significanty more likely to develop type-2 diabetes than people who rarely consume the food. The study found that the risk of developing diabetes was 55% higher for Asian populations and 12% higher for western populations in those who consume 3 to 4 servings of white rice a day compared to those who rarely consumed white rice.

The results are controversial however because most countries that consume large amounts of rice actually have a very low diabetes incidence, suggesting that if white rice consumption is a risk factor for diabetes, it is much less important than other established risk factors such as a sedentary lifestyle and obesity.

Brown rice consumption on the other hand generally shows an inverse association with diabetes risk. For example, a Harvard study, published in 2010, found that two servings of brown rice a week cut the risk of developing type-2 diabetes by about 11%. The differing results between brown and white rice are likely due to the lower GI, and more favourable nutrient profile of brown rice.

When compared to potatoes, white rice has a similar GI, but lower amounts of magnesium and fiber, two components that are beneficial for diabetic patients. 100 grams of cooked white rice has no dietary fiber and only 8mg of magnesium compared to 1.8g of fiber and 20mg of magnesium in the same amount of boiled potatoes. In contrast, brown rice has 1.8g of fiber and an impressive 43mg of magnesium.

This doesn’t necessarily mean that white rice should be avoided altogether however regular eaters of white rice should ensure that they get adequate amounts of magnesium and dietary fiber from other sources.

The GI of rice normally fals between 55 and 75 making it a high GI food. Diabetics should therefore be aware that consuming a large amount of rice will have a significant effect on blood sugar levels. The impact on blood sugar levels can be reduced by combining rice with high fiber, low GI foods such as beans, green vegetables, avocados, or nuts,

The GI of rice varies depending on the degree of processing, grain size, cooking time amd amylose content. The average GI values for selected rices are shown below.

  • Jasmine: 109
  • White (Short Grain):74
  • White (Long Grain):60
  • Brown (Short Grain): 64
  • Brown (Long Grain): 55
  • Wild: 56
  • Basmati: 56

Brown rice generally has a lower GI than white rice because the high fiber bran and germ components of the rice grain are still intact. Long grain rice has a lower GI than short grain rice because long grain rice has a smaller surface area relative to volume for digestive enzymes to work on, which results in a slower digestion speed. Cooking time also influences the GI of rice, in general overcooked rice has a higher GI than slightly undercooked rice.

Wild rice is generally sold as a whole grain and has more protein and less carbohydrate than regular brown rice however it is more expensive than regular rice due to lower yields and harvesting difficulties.

The GI of a rice variety depends on the relative proportions of the two components of starch, amylose and amylopectin. Amylose is a more densely packed structure that amylopectin and therefore takes longer to digest. Rice generally has anywhere from 0-25% amylose. Diabetics should generally stick to high-amylose varieties of rice as they will have a reduced effect on blood sugar levels. Any rice labelled glutinous, sticky, waxy, mochi, or sweet, is likely to contain very low amounts of amylose and will therefore have a higher GI than rice varieties with a higher amylose content. Basmati rice has one of the highest amylose contents of any variety of rice and is a great option from diabetics. Basmati rice is generally eaten as a white rice, although brown basmati rice can be found in some speciality stores.