News Briefs

For better blood glucose, it’s the GI not the colour of rice that counts
Consuming more white rice appears to be associated with a higher risk for developing type 2 diabetes, whereas consuming more brown rice may be associated with a lower risk for the disease, according to a report from researchers at Harvard University published in Archives of Internal Medicine. The NHS Choices Behind the Headlines review of this study makes the point that: 'Despite the quality of the study, the results don't actually prove that eating white or brown rice directly raises or lowers the risk of type 2 diabetes,' as cohort studies like this can draw associations but cannot prove causation. They go on to say that the researchers' conclusions are in line with general recommendations that people should include more wholegrains in their diet because they are thought to have a number of health benefits.

GI Group: While choosing brown rather than white rice may help reduce your risk of getting diabetes (along with being active and eating a healthy balanced diet), it's the GI of the rice that matters. The Harvard researchers said that the average GI for white rice was 64 and for brown rice it was 55. The higher GI of the white rice, and the loss of fiber, vitamins, magnesium and other minerals, lignans, phytoestrogens, and phytic acid, in the refining process are the likely factors for the increased diabetes risk.

However, neither colour nor size are a good guide to the GI of rice. Its amylose content is what counts. Amylose is a kind of starch that resists gelatinisation. Although both white and brown rice are grain foods, when you cook them, millions of microscopic cracks in the grains let water penetrate right to the middle of the grain, allowing the starch granules to swell and become fully ‘gelatinised’, thus very easy to digest. It’s true that popular white rices like jasmine have a high GI. But brown rice often has a surprisingly high GI too. This is because the insoluble fibre around brown rice is not viscous and it’s micro-thin. It’s easy for enzymes to attack the starch in rice because the milling operation has resulted in thousands of minute channels that allow water to hydrate the grain and gelatinise the starch during cooking. Greater gelatinisation of starch means higher GI. Finally, don’t forget that a healthy low GI diet is associated with a lower risk of diabetes than either eating brown rice, or wholegrains in general.

The bottom line: For better blood glucose, opt for the lower GI varieties with a higher amylose content such as Basmati, Doongara Clever Rice, Moolgiri medium grain or the Uncle Ben’s Ready Rice brown rice pouch range. These high-amylose rices stay firm and separate when cooked. But you still need to keep portions moderate, even when you choose a low GI rice as eating too much can have a marked effect on your blood glucose. Here’s our tip: a cup of cooked rice combined with plenty of mixed vegetables can turn into three cups of a rice-based meal that suits any adult’s daily diet.

Better blood glucose for kids with type 2
The incidence of type 2 diabetes and impaired glucose tolerance in young people is sweeping the world at an alarming rate. In Australia for example, nearly 1 in 10 young people with diabetes now has type 2. Twenty years ago it was almost unheard of in this age group. Managing type 2 involves helping the kids normalise their blood glucose levels, reduce their blood fats and blood cholesterol and prevent the progression or development of complications.

Lauren Gellar
Lauren Gellar M.S., M.ED., CHES

A small cross-over pilot study published in the Journal of Pediatrics has found that the average mean daytime blood glucose was significantly lower when the kids ate a low GI diet (GI 40) compared with the day they ate a higher GI diet (GI 64).

For the study, 12 obese young people aged between 7 and 16 with type 2 diabetes or impaired glucose tolerance were served a full day of high GI and a full day of low GI meals (matched for carbs, protein and fat content) in a supervised clinic setting. Participants demonstrated significantly lower mean daytime blood glucose and a trend toward lower variability, suggesting a clinically relevant impact of reducing glycemic index.

In their conclusion, the authors, Lauren Gellar and Dr Tonja Nansel write: ‘Our findings are of particular importance given that children who develop disorders of glucose metabolism are likely to be a particularly high-risk group. Thus the ability to demonstrate substantial differences in blood glucose with a dietary change lasting a single day suggests that a low GI diet is a promising approach for achieving improved health outcomes.’ For reprints of this study contact Dr Tonja Nansel

Resistance exercise better than aerobic for blood glucose
Ten weeks of resistance exercise (3 sessions a week of typically around 35 minutes) were associated with significantly better glycemic control in adults with type 2 diabetes compared with aerobic treadmill exercise although the average energy expenditure for both exercise groups was similar according to a study published in Diabetology and Metabolic Syndrome.

Before each session, participants in both groups performed warm up exercises, consisting of stretching exercises for the major muscle groups and there were no differences between the groups concerning their perceived exertion,’ write the authors. ‘The resistance training group followed an individually monitored progressive resistance training program using multiple-station universal weight machines. Seven exercises were used for resistance training that encompassed knee and hip flexion/extension, shoulder flexion/extension, adduction/abduction, elbow flexion/extension and a chest press. Three sets of 8–10 repetitions were performed for all exercises,’ they report.

If you take metformin, get your B12 checked
If you have diabetes and have been taking metformin (brand names such as Glucophage, Glucophage XR, Fortamet, Riomet, Glumetza, and others) for years, ask your doctor to check the level of vitamin B12 in your blood. A recent study published in the British Medical Journal reports that metformin may lead to a B12 deficiency. We need minute amounts of this vitamin (also known as cyanocobalamin or cobalamin) a day for the production of red blood cells and to maintain healthy nerves and a healthy brain.

‘Our data provide a strong case for routine assessment of vitamin B-12 levels during long term treatment with metformin,’ concludes Coen Stehouwer. The 4-year study tracked 390 people with type 2 diabetes and found that the 196 participants taking metformin had a 19% reduction in their vitamin B12 levels compared with the 194 participants who had taken a placebo, who had almost no B12 change. The reduced levels of vitamin B12 in the metformin group also persisted and became more apparent over time, they said.

Where do you get it? Most of us get plenty of vitamin B12 from our diet as red meat, milk, cheese, eggs, fish, shellfish and fortified breakfast cereals and enriched soy or rice milk. You can also take a supplement. What about mushrooms? Dietitian Glenn Cardwell writes: ‘To accurately establish the levels of B12 in mushrooms, scientists at the University of Western Sydney checked mushroom samples from the major mushroom growing centres around Australia in 2009. Writing in the Journal of Agricultural and Food Chemistry they report that there is a modest amount of B12 in mushrooms, closer to 5% of daily needs in a serve (three button mushrooms). It is the same type of B12 as found in meats and seafood, so it is the type of B12 that the body finds very easy to use.