News Briefs

Bread: This for that #1
The simple change from regular white bread to a low GI bread could reduce the risk of type 2 diabetes according to Australian researchers from the Cancer Council of Victoria. The study published in Diabetes Care looked at the diets and health records of more than 36,000 men and women in Australia for four years and found white bread was the food most strongly related to diabetes incidence—participants who ate the most white bread (more than 17 slices per week) had the highest risk of type 2 diabetes.

A small Swedish cross-over study of seven women with impaired glucose tolerance and a history of gestational diabetes published in the European Journal of Clinical Nutrition highlights the immediate value of making the ‘this for that’ switch. For the study, the women were given either a low GI bread that was specially baked and was rich in fibre or a high GI, low fibre bread during consecutive 3-week periods separated by a 3-week washout period. The results were unanimous. All the women reduced their post-meal insulin responses after eating low GI, high fibre bread compared with eating the high GI, low fibre bread.

Bread: This for that #2
‘A lack of satisfying, filling foods is a hurdle for many people when trying to maintain a balanced, healthy diet,’ says Prof. Jennie Brand-Miller. ‘We found that your daily bread choice can play a role in satisfying hunger and decreasing food intake at a subsequent meal.’ Researchers in the Human Nutrition Unit at Sydney University carried out the lab-based [unpublished] study for George Weston Foods from January–March 2008.

French toast with grainy bread

Twenty healthy weight (BMI 18–25) volunteers aged 18–45 were randomly asked to breakfast on either two slices of Burgen Wholemeal & Seeds bread (GI 39) or two slices of standard white sandwich bread (GI 70) with margarine and jam and a glass of water and rank their feelings of fullness. They also had to list their subsequent meal’s food intake. The volunteers stated that they felt fuller for longer after the low GI bread breakfast and, on average, reduced their intake at the next meal by 500 kilojoules (120 cals) and 4 g of fat compared with the standard white bread breakfast. They also had a lower glycemic response to the low GI bread brekkie, which may have contributed to keeping hunger pangs at bay. The low GI bread was also a good source of fibre and provided some protein which may have also helped to provide the greater satiety response.

Does gluten cause your gut symptoms?
At the Nutrition Society of Australia conference in December 2009, PhD candidate Jessica Biesiekierski reported on her initial study that found for the first time, evidence that gluten itself may trigger gut symptoms such as bloating, wind and pain and also fatigue in individuals who do not have coeliac disease. To understand how and why, Jessica is currently recruiting for a follow up study. Details follow.

Jessica Biesiekierski
Jessica Biesiekierski

Volunteers are required for an Australian trial investigating gluten intolerance in people who do NOT have coeliac disease. The research team is seeking participants living in Melbourne (Australia) who:
The research will be conducted by the Department of Gastroenterology, Box Hill Hospital. The study will involve consuming gluten at two different levels for 7 days each (all food will be provided – and Jessica has hired a pastry chef to make sure the food is fabulously tasty), completing bowel symptom and food diaries, a blood sample and collecting faecal samples. All information is kept strictly confidential. To find out more information about this new research study, contact:

Email:Jessica.Biesiekierski@med.monash.edu.au
Tel: (03) 9094 9530 or 0422 176 052


Relieving stress on insulin-producing cells may prevent diabetes
Cells in your body are constantly churning out poisonous forms of oxygen (oxidants) and mopping them up with a countervailing force of proteins and chemicals (anti-oxidants). This balancing act of oxidative stress is particularly likely to go haywire in beta cells, the insulin-producing cells that malfunction and then start to die off in Type 2 diabetes.

Writing in The FASEB Journal, scientists at Joslin Diabetes Center report on a study (in mice) that found that a relatively little-studied enzyme plays a central role in defending beta cells against oxidants, but is damaged by the high levels of blood glucose produced in diabetes.

Dr Robert C Stanton
Dr Robert C Stanton

‘The research showed that an essential antioxidant called NADPH, on which all cellular antioxidants ultimately depend, can regulate the growth and death of beta cells,’ says Joslin Principal Investigator Robert Stanton, M.D. The researchers went on to demonstrate that increases in the level of blood glucose cause a decrease in NADPH that ends up killing beta cells – and that increasing the level of this antioxidant guards against this effect, at least in mouse beta cells. Stanton says the discovery raises hopes of finding drugs that protect the enzyme, and thus the beta cells and their insulin production. Such drugs could help to stem the tide against type 2 diabetes, which now afflicts more than a quarter of a billion people worldwide.

Coffee, tea and diabetes risk
Drinking three to four cups of regular or decaffeinated coffee and tea may reduce the risk of developing diabetes by 25% says a new review and meta-analysis of the data from prospective studies published in Archives of Internal Medicine. The reviewers, led by Dr Rachel Huxley from the University of Sydney, Australia found that for each additional daily cup of coffee was associated with a 7% reduction in the excess risk of diabetes.

Dr Rachel Huxley
Dr Rachel Huxley

Huxley and her co-workers reviewed data of over 500,000 individuals with over 21,000 cases of type-2 diabetes from prospective studies. Eighteen studies looked at coffee, six studies also included information about decaffeinated coffee, and seven studies reported on tea consumption. In addition to risk-lowering effects of additional regular coffee consumption, three to four cups of decaffeinated coffee were associated with a 33% lower risk of diabetes, compared to drinking no decaf. Tea drinkers also benefited, with three to four cups associated with a one-fifth lower risk. Huxley and her co-workers noted that because of risk reductions associated with decaffeinated coffee, the effects were unlikely to be due solely to caffeine. Other compounds in coffee and tea, such as magnesium, antioxidant lignans or chlorogenic acids, may be involved.

cappuccino

Comment: Professor Lars Rydén (spokesperson for the European Society of Cardiology), who is a diabetes specialist, says: ‘This is a cautiously and carefully conducted meta-analysis which means authors have carefully conducted studies although each are too small to give an answer to the question although they indicate a positive correlation between the consumption of coffee and a decreasing occurrence of diabetes. So the principle is that if you drink coffee whether it is decaffeinated or not, you have less chance of developing diabetes. The data has been strengthened by bringing several studies together.

There are sometimes claims that coffee may do harm, that it may increase the propensity to cardiovascular disease, but there is no evidence for this. The message is that people may drink coffee safely. Coffee from this point of view may actually be of benefit, as well as reducing the risk of getting diabetes – although the reduction is small (around 7%).’

‘Coffee helps, but other things are even more important. Those who are overweight should reduce their bodyweight by 5–10% – not too much – and include physical activity such as a brisk walk for 30 minutes a day. Then those people who are at risk of developing diabetes will reduce this risk by 40–50%.’