Low GI benefits for young people with type 1 diabetes
‘A low GI diet may reduce glucose excursions and improve glycemic control in children with type 1 diabetes,’ says Dr Tonja Nansel from the US National Institute of Child Health and Human Development, commenting on her pilot study published in Diabetes Care in April. She also made the point that ‘this effect was observed despite the fact that the children used basal-bolus insulin regimens, in which their insulin dose was specifically matched to the amount of carbohydrate consumed’.
‘In fact’, she said, ‘when you account for the differences in carbohydrate consumed due to treating low blood glucose and the differences in the amount of insulin taken due to treating high blood glucose, the children actually had a greater number of carbs per unit of insulin when they ate the low GI diet – and they still showed better blood glucose levels’.
The study recorded blood glucose responses to low and high GI meals in 20 young people (aged 7–16) with type 1 diabetes using continuous blood-glucose monitoring. The study was carried out over five days in both a structured clinical setting and in the home environment. In their findings, the researchers report that the low GI diet resulted in significantly lower average daytime blood glucose. They noted that the fact that blood glucose levels were not different during the night time supports the understanding that a low GI diet affects blood glucose levels primarily by decreasing the rise in blood glucose that happens after eating. More mild hypos had to be treated on the low GI diet suggesting that there needs to be attention to safety in any major dietary changes and that a lower GI diet may reduce insulin requirements.
Dr Nansel explained that the benefits of improved blood glucose control for children with diabetes are substantial. ‘Many young people with diabetes and their families say that one of their biggest frustrations in managing diabetes is dealing with high blood glucose levels. The more the blood glucose is out of range, the more children are at risk for long-term health complications. Seeing a reading on their blood glucose meter that is considered “too high” can be a source of worry, and can even spark parent-child conflict. A way of eating that decreases these high blood glucose fluctuations could both improve long-term health for children with diabetes, and perhaps even decrease some of the stress of living with diabetes.’
Dr Tonja Nansel’s primary research interests are in the management of type 1 diabetes in children and their families, and in developing programs to promote healthful eating among families. To find out more about this study and her findings (including what the children actually ate, low GI foods such as brown basmati rice and black bean brownies), check out her presentation of the study’s findings at the 2007 ADA meeting.
– Diabetes Care, Volume 31, Number 4, April 2008
Dr Tonja Nansel
Bitter melons and blood glucose
Many plants have traditionally been used to treat type 2 diabetes. Indeed, along with diet, plant preparations formed the basis of treatment until the introduction of insulin in 1922. One fruit long associated with treating diabetes is bitter melon. Writing in Phytomedicine Raman Lau reported back in 1996 that ‘Unripe fruits, seeds and aerial parts of bitter melon (Momordica charantia) have been used in various parts of the world to treat diabetes.’
A team from Australia’s Garvan Institute of Medical Research along with the Shanghai Institute of Materia Medica, reported in March Chemistry and Biology that they have uncovered bitter melon's therapeutic properties – four bioactive compounds that all appear to activate the enzyme AMPK, a protein that regulates the body's metabolism and affects glucose uptake. Exercise also activates AMPK in muscle, which in turn mediates the movement of glucose transporters to the cell surface, a very important step in the uptake of glucose from the circulation into tissues in the body. This is a major reason that exercise is recommended as part of the normal treatment program for someone with type 2 diabetes.
‘We can now understand at a molecular level why bitter melon works as a treatment for type 2 diabetes,’ said Prof David James, director of the diabetes and obesity program at the Garvan. ‘By isolating the compounds we believe to be therapeutic, we can investigate how they work together in our cells.’ Garvan scientists involved in the project, Drs Jiming Ye and Nigel Turner, stress that while there are well known diabetes drugs on the market that also activate AMPK, they can have side effects. ‘The advantage of bitter melon is that there are no known side effects. Practitioners of Chinese medicine have used it for hundreds of years to good effect,’ said Dr Ye.
– Chemistry and Biology, Vol 15(3), 263-273, 21 March
What are they and how do you use them?
Bitter melon also called bitter gourd and balsam pear is a cousin of squash, watermelon and cucumber. Native to the tropics, it’s widely cultivated in Asia for its ‘bubble-wrap’ textured, green, immature fruit (12–30 cm long) that's stuffed, pickled, and sliced into various dishes, hot and cold. Like eggplant, it needs to be ‘degorged’ or salted first to take away the bitterness (this involves slicing it, salting the slices, then allowing them to drain in a colander or on a paper towel for 20 minutes or so before rinsing or blotting and patting dry). The young leaves and tips are also edible.
Our invaluable resource for all Asian food matters is Charmaine Solomon. She prefers her bitter melon fried to a golden brown as in her Fried Bitter Gourd Salad (see our recipes this month) rather than raw and sliced thinly in a salad, her jazz musician husband Reuben’s favourite way. Check out Charmaine’s Encyclopedia of Asian Food for recipes. There are also two or three recipes in The Okinawa Diet Plan as ‘goya’, its local name is popular in Okinawan cuisine. You’ll find bitter melons in season in Asian produce markets and larger fruit and vegetable markets.
The tai chi factor
Two separate small but encouraging studies by researchers in Taiwan and Australia published online in the British Journal of Sports Medicine in April report that simple tai chi exercises may help in managing type 2 diabetes. In the Taiwan study, Dr Kuender Yang and colleagues at Chang Gung Memorial Hospital matched 30 middle-aged and older adults with type 2 diabetes with a diabetes-free, age-matched ‘control’. The participants were given a program of 37 standardised tai chi movements which they practised in 60 minutes training sessions three times a week – and were encouraged to continue at home. After 12 weeks, the ‘control’ group had no significant changes in any diabetes related parameters. The participants with type 2 diabetes, however, had a significant decline in their HbA1c level (a measure of long-term blood glucose control) and increased levels of anti-inflammatory interleukin-12 (which boosts immune response), while their T cell activity (a sign of health) also increased.
In the Australian study, Dr Xin Liu and colleagues at the University of Queensland designed a special tai chi/qigong program for 11 adults with elevated blood glucose. The participants exercised for 90 minutes, three times a week and were encouraged to practise at home (most did). After 12 weeks of regular exercise, the participants showed significant improvement in BMI, waist circumference and blood pressure. There was also a small improvement in HbA1c, fasting insulin and insulin resistance.
– British Journal of Sports Medicine: Taiwan study
– British Journal of Sports Medicine: Australian study
Star foods: Selecting a winning team of foods for great health
By Dr Joanna McMillan Price and Judy Davie
‘What you eat has the power to influence the way you look, how you feel, how much energy you have, your ability to perform mental tasks, your ability to exercise, and your general state of happiness – and that’s before we even start talking about lowering the risk of chronic disease,’ say Joanna and Judy. In Star Foods, this gorgeous and dynamic duo help you create your own winning team of star performing foods to maximise your chances of achieving and maintaining good health. There are more than 60 deliciously healthy recipes including the following great tasting, quick meal packed with nutritional goodies.
Sardine, avocado and capsicum grill
- Brush the sardines with olive oil and a sprinkle of lemon juice. Heat a grill pan and cook sardines for 3–4 minutes on one side only.
- Spread each slice of toast with avocado and sprinkle capers over the top. Season with black pepper and a little more lemon juice.
- Lay the rocket over the avocado. Top with sardines and sliced capsicum and serve.
1472 kJ/ 350 calories; 15 g protein; 21 g fat (includes 5 g saturated fat); 23 g carbohydrate; 3.8 g fibre
Ride up the corporate ladder
May is National Bike Month in the US. The League of American Bicyclists is promoting Bike-to-Work Week from May 12-16 and Bike-to-Work Day on Friday, May 16 (check their website for details). Our New York publisher packs his bike before his toothbrush and rides everywhere, even on one notable occasion across Sydney in peak hour, from recollection in the pouring rain, to visit Sydney University’s GI testing centre. Here are 10 top reasons to ride to work:
- Stay healthy.
- Save time, and get your daily dose of exercise.
- Help save the environment.
- Savour the great outdoors.
- Parking is a breeze.
- Enjoy the satisfaction of sailing past stationary cars.
- Meet fellow commuters at lights and bike racks.
- Save money.
- Make the most of roads, bike tracks and shared pedestrian pathways to cross town.
- Dream up new ventures.