1 April 2012

News Briefs

Rice and diabetes risk.
A meta-analysis and systematic review in the BMJ reports that higher white rice intake is associated with a significantly elevated risk of type 2 diabetes, especially among Asian populations. The researchers conclude: ‘The recent transition in nutrition characterised by dramatically decreased physical activity levels and much improved security and variety of food has led to increased prevalence of obesity and insulin resistance in Asian countries. Although rice has been a staple food in Asian populations for thousands of years, this transition may render Asian populations more susceptible to the adverse effects of high intakes of white rice, as well as other sources of refined carbohydrates such as pastries, white bread, and sugar sweetened beverages.’ Not surprisingly, this study made the headlines and was reviewed by NHS Choices. You can read their full review HERE.

One key piece of information is missing from the study. We don’t know the varieties of rice consumed. The GI of rice (brown or white) depends on its amylose content– a kind of starch that resists gelatinisation. When you cook rice, 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. Greater gelatinisation of starch means a higher GI. However, the more amylose in the rice, the less gelatinisation and the lower the GI. In fact, the GI values of rices SUGiRS has tested range from 53 (Doongara Clever Rice) up to 89 (jasmine rice). That's quite a big difference in glycemic impact!

We recommend you choose the lower GI varieties of rice with a higher amylose content such as basmati (GI 58), Doongara Clever Rice (GI 53) and the Uncle Ben’s Ready Rice range (GI 46–51). 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 low GI 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.

Looking beyond counting carbs.
It’s well established that low GI diets improve glycemic control in diabetes and may decrease the risk of developing type 2 diabetes. However, there is still some controversy about its relevance for the rest of us out here in the real world because of concerns that it is difficult to choose low GI foods, that values are imprecise, and that it doesn't predict the glycemic response to normal mixed meals due to the high day-to-day variation of glycemic responses and the confounding effects of fat and protein. A recent study in the Journal of Nutrition however, supports the notion that one should perhaps look beyond simply the grams of sugar or total carbohydrates in your diet to determine the actual glycemic risk of foods. The Canadian research team including Profs Tom Wolever and Arya Sharma found that the GI is a significant and more important determinant of individual glycemic responses elicited by self-selected breakfast meals, than just the intake of carbohydrates. The effects of fat, protein, dietary fibre, age, sex, and the participants' BMI were not significant determinants of glycemic response.

Quit the sit.
Overweight office workers, drivers and call centre staff who sit for long periods could improve their health by simply breaking up their sitting time with frequent activity breaks according to new research by Australia’s Baker IDI Heart and Diabetes Institute, published in Diabetes Care.

Dr David Dunstan
Associate Professor David Dunstan walks the talk and quits the sit: he stands at his desk!

Lead researcher, Associate Professor David Dunstan explains: ‘When we sit, we have muscle “dis-use” – our muscles are essentially “sleeping”. When we’re up and moving, we’re contracting muscles and it appears that these frequent contractions throughout the day are beneficial for helping to regulate the body’s metabolic processes. The evidence that sitting is hazardous to health is now quite compelling. But for the vast majority of us who work in desk-bound sedentary jobs, our choice to sit appears largely out of our control. This prompted me to ask the question: How ridiculous is it that people now sit longer than they sleep and what, if anything, can be done about sitting for long periods?

In response, my research group set about identifying how frequently, and at what activity intensity, one would need to break up sitting time in order to counteract its negative consequences. By examining spikes in participants’ BGLs after consuming a high-calorie meal, we discovered that glucose levels and insulin sensitivity improve by as much as 30% following frequent short breaks in sitting.

Our next step was to identify the frequency and intensity of activity required to break up sitting time. We found that the benefit of walking at a light intensity pace was almost identical to walking at a moderate intensity pace – suggesting that it was not so much the amount of effort put into the break that was critical. The simple act of standing up and moving was, itself, beneficial.

When you consider that around 60% of Australians are overweight or obese, it’s clear we need new approaches to obesity prevention and the workplace is an ideal place to start. Current Australian occupational health and safety guidelines recommend desk-bound employees take a break from their computer screen every 30 minutes or so to reduce eye strain. We’d like to see these guidelines extended to encourage workers to take frequent breaks that involve some kind of physical movement.’

Does eating red meat raise the risk of premature death?
NHS Choices reviewed the headline hitting study Red Meat Consumption and Mortality published in Archives of Internal Medicine and concludes: ‘This was a well-conducted study but it could not conclusively prove that red meat raises the risk of premature death, although the results are of key interest and the evidence is mounting on the issue. According to UK dietary surveys, 4 in 10 men and 1 in 10 women eat more than 90g (3oz) of red and processed meat a day. The Department of Health recommends that people eating more than 90g (3oz) of red and processed meat a day limit their intake to no more than 70g (2½oz) a day in cooked weight. That is about the size of a large beef burger … Red meat is a good source of protein and certain nutrients such as iron, some vitamins and zinc, but it is already recognised that it is likely to raise the risk of cancer especially bowel cancer.’ You can read the whole review HERE.

Excess Baggage.
GI News contributor Dr Joanna McMillan is the nutritionist for Channel Nine’s Excess Baggage. What’s different about this weight loss reality show is that Joanna hasn’t give the contestants a diet but has taught them how to eat well, listen to their bodies for hunger cues, time their food intake around their workouts and relax and enjoy good food.

Dr Joanna McMillan
Dr Joanna McMillan

‘I can’t tell you what happens in the end,’ she says, ‘you'll have to keep watching us online or on GO! to find out, but what I can tell you is that our contestants did amazingly well. Our psychologist Dr Tim Sharp worked with them on their psychological barriers to eating well and we both stressed the importance of mindful eating, while they upped the ante with their exercise in the hands of our trainer Christian. The results were revealed at our final check-ins last week and I have to admit to feeling very emotional seeing their progress as a whole. It reassured me that what we’re teaching works – and it works at the level of the mind and the body. They’re not only leaner, but they’re happier as a result of true lifestyle change.

My take-home message
? If you’re contemplating the latest fad diet, stop and think. Long term the best results come from learning how to eat well, improving your relationship with food and moving your body in the right way. You’ll know when you’re achieving it – that’s when you feel your inner mojo alive and well.’

Download Ideology not science.
Opponents of the nanny state show a more sophisticated understanding of the science than public health campaigners says public health academic Dr Michael Keane arguing that the Nanny State policy solutions designed by his colleagues have little sound basis in science. You can download the paper HERE.