GI News - March 2021

 

GI News is published by the University of Sydney, School of Life and Environmental Sciences and the Charles Perkins Centre, and delivered to the mailboxes of our 97,000 subscribers. Our goal is to help people choose the high-quality carbs that are digested at a rate that our bodies can comfortably accommodate and to share the latest scientific findings on food and diet with a particular focus on carbohydrates, dietary fibres, blood glucose and the glycemic index.

Publisher: Professor Jennie Brand-Miller, AM, PhD, FAIFST, FNSA, PhD
Editor: Alan Barclay, PhD, APD
Contact GI News: glycemic.index@gmail.com

Sydney University Glycemic Index Research Service
Manager: Roslyn Muirhead, PhD, APD, AN
Contact: sugirs.manager@sydney.edu.au

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FOOD FOR THOUGHT

THE FIRST COMPENDIUM OF GI VALUES OF NON-WESTERN FOODS 

Evaluating the quality of carbohydrate in the diet could be considered more important than ever. Markers of quality such as wholegrains, fibre content and sugars are routinely included on food labels and in national food composition tables. But another marker of carbohydrate quality, the glycemic index (GI), is rarely available from these sources. Instead, informed consumers, researchers and health professionals must rely on multiple sources including papers published in the scientific literature, online databases and books such as The Shoppers Guide to GI Values. In the lucky country (Australia!) and New Zealand, GI claims are permitted on the labels of healthier foods, and a not-for-profit food endorsement charity, the GI Foundation, also promotes healthy low GI foods at the point of sale. 

The first GI values of 62 common foods using a standardized methodology were published 4 decades ago by David Jenkins, Tom Wolever and others at the University of Toronto. Since then, the University of Sydney has played an important role of compiling and updating reliable, international tables of GI values. The tables have been instrumental in improving the quality of research examining the relation between dietary glycemic potential and health. Indeed, they are among the most cited papers in the field. In 1995, there were 565 entries in the edition published in the American Journal of Clinical Nutrition. By 2002 there were 750 foods, and by 2008 there were 2487 in the third edition published in Diabetes Care. And I am pleased to say that after a long gestation, the 2021 edition with international authorship and over 4000 foods, is currently under review. 

In the meantime, our colleagues in Singapore, led by Professor Jeya Henry have published the first compendium of 940 non-Western foods, citing over 150 papers. The table includes data from Malaysia, Thailand, Indonesia, Philippines, Japan, Korea, China, Taiwan, Hong Kong, India, Sri Lanka, Emirates, Oman, Saudi Arabia, Lebanon, as well as Singapore. This is an important milestone because the vast majority of published GI values are of Western origin, notably European, Australian and North American. We know that GI values are altered by the degree of cooking and processing and this will vary from country-to-country. Moreover, in Asian countries, carbohydrate foods provide a much greater proportion of dietary energy – around 60%. Hence, the potential to reduce postprandial glycaemia by substituting high GI foods for lower GI counterparts is also magnified. Singapore has the distinction of being the only country with two GI testing services using the ISO methodology. And recently, the China National Research Institute of Food and Fermentation Industries has offered a commercial GI testing service after extensive training at the University of Sydney. In collaboration with Sydney, CNRIFFI has also translated the online 2008 International Tables of GI and glycemic load into Chinese. We hope these wonderful developments will translate into healthier carbohydrate food offerings throughout Asia, the Middle East and beyond. 

Read more: 

• The Shoppers Guide to GI Values 
• Sydney University’s searchable on-line GI database 
• Henry and colleagues. A glycaemic index compendium of non-western foods. 

      
Professor Jennie Brand-Miller holds a Personal Chair in Human Nutrition in the Charles Perkins Centre and the School of Life and Environmental Sciences, at the University of Sydney. She is recognised around the world for her work on carbohydrates and the glycemic index (or GI) of foods, with over 300 scientific publications. Her books about the glycemic index have been bestsellers and made the GI a household word.

WHAT’S NEW?

LOW GLYCEMIC INDEX DIETS IMPROVE HEALTH OF SOUTH INDIANS WITH DIABETES 

Traditional Indian diets are rich in dietary fibre and wholegrains, which generally have a lower GI than more refined grains. However, similar to many other countries, there has been a transition to more refined grains over the last few decades. This may be one factor contributing to the increasing prevalence of type 2 diabetes in the Indian population. 

With this in mind, researchers from the Amrita Institute of Medical Sciences and Research Centre in India have recently published two papers exploring the role of glycemic index in South Indian diets, showing several benefits of choosing low GI foods. 

In the first paper published in Nutrients, they reported on the findings of a randomised controlled trial investigating the effect of a low GI diet on blood glucose levels and body composition in people with type 2 diabetes in South India. A total of 40 people aged 35-65 years were recruited and randomised to follow either a low GI diet plan or their usual diet (the control group) for 6 months. Dietary advice was reinforced by the study dietitian throughout the study period. Compared to the control group, people in the low GI diet group had significantly greater reductions in weight, body mass index (BMI) and body fat levels, including abdominal fat. They also had significantly greater reductions in HbA1c (a measure of average blood glucose levels over the past 2-3 months). 

The second paper published in the International Journal of Environmental Research and Public Health reported on the findings from 80 subjects from the same study, this time looking at cardiovascular (heart and blood vessel) risk factors. Again, the researchers found greater reductions in weight and HbA1c levels in the low GI diet group compared to the control group. They also found greater reductions in insulin levels, insulin resistance, triglycerides (blood fats), C-reactive protein (CRP) and apolipoprotein B (ApoB). ApoB is the main protein found in LDL-cholesterol and high levels are associated with an increased risk of heart disease. CRP is a marker of inflammation in the body and is also associated with heart disease risk as it can indicate inflammation in the blood vessels to the heart. 

Taken together, the findings of these two studies suggest that switching to a low GI diet can help with weight loss, improve blood glucose levels and insulin sensitivity and improve cardiovascular risk factors in South Indian people with type 2 diabetes. 

The low GI diet in these studies included foods with a low GI that are traditionally used in South Indian cuisine. These included red rice, barley and whole wheat flour puttu, rolled or steel-cut oats, Rose Matta rice, broken wheat, green gram, and wholewheat flour roti. 

Read more: 

• Pavithran and colleagues. The Effect of a Low GI Diet on Truncal Fat Mass and Glycated Hemoglobin in South Indians with Type 2 Diabetes-A Single Centre Randomized Prospective Study. Nutrients. 2020. 
• Pavithran and colleagues. South Indian Cuisine with Low Glycemic Index Ingredients Reduces Cardiovascular Risk Factors in Subjects with Type 2 Diabetes. Int J Environ Res Public Health. 2020.

    
Kate Marsh is an is an Advanced Accredited Practising Dietitian, Credentialled Diabetes Educator and health and medical writer with a particular interest in plant-based eating and the dietary management of diabetes and polycystic ovary syndrome (PCOS).    
Contact: Via her website www.drkatemarsh.com.au.

DIABETES CARE

DIABETES IN SOUTH-EAST ASIA 

In 2019, there were an estimated 88 million people in South-East Asia living with diabetes and the number of people with diabetes is projected to increase to 153 million by 2045 unless successful preventative measures are implemented. There is mounting evidence that Asians have higher postprandial (after-meal) blood glucose levels and poorer insulin sensitivity than Caucasians for the same foods, which puts them at increased risk of developing type 2 diabetes. Improved prevention and management of diabetes are therefore now public health priorities in South-East Asian countries such as India, Malaysia, Singapore and Thailand. 

South-East Asians consume approximately 60% of their total energy intake from carbohydrates compared with 42% for Caucasians living in the region. Rice and noodles are the main carbohydrate staples in the South-East Asian diet, and studies have shown that consumption of rice and noodles has been linked to hyperglycemia and risk of developing type 2 diabetes. In addition to rice and noodles, the traditional Asian diet is heavily represented by foods derived from cereals, flours, and other starches such as rice porridge, steamed buns (bao), and glutinous rice cakes (kuehs). 

The challenge many people living in South-East Asia face with regard to managing their carbohydrate consumption is that high-carbohydrate foods are not just sustenance, but are an important part of South-East Asian culture. Foods such as rice are part of the region’s cultural identity, meal, and habits, and individuals may choose to compromise health over food. Therefore, an effective approach toward managing diabetes in South-East Asia would be to improve carbohydrate quality in addition to reducing carbohydrate quantity. In other words, reducing the glycemic load of the South-East Asian diet. 

Glycemic load can be reduced by substituting lower GI options for regular high GI varieties. From a food perspective, it is possible to modify the food composition and structure through ingredients and processing to reduce the amount of carbohydrate, limit the rate of digestion by controlling enzymatic activity/accessibility, or slow down the rate of glucose absorption. Specific examples of what can be done are discussed next in PERSPECTIVES. 

Read more: 

• IDF DIABETES ATLAS Ninth edition 2019  

Alan Barclay, PhD is a consultant dietitian and chef (Cert III). He worked for Diabetes Australia (NSW) from 1998–2014 . He is author/co-author of more than 30 scientific publications, and author/co-author of  The good Carbs Cookbook (Murdoch Books), Reversing Diabetes (Murdoch Books), The Low GI Diet: Managing Type 2 Diabetes (Hachette Australia) and The Ultimate Guide to Sugars and Sweeteners (The Experiment, New York).
Contact: You can follow him on Twitter, LinkedIn or check out his website.

PERSPECTIVES: Dr ALAN BARCLAY

LOWERING THE GLYEMIC IMPACT OF SOUTH-EAST ASIAN DIETS 

Food is not merely a collection of nutrients, and neither is it medicine – it’s so much more than that. From the day we are born to the day we die, food not only nourishes us, but it provides pleasure, social interaction and anchors us to our family, community, culture and point in time. Food should not only be good for us — it should also be enjoyable, affordable and environmentally sustainable. 

Rather than trying to change the cultural food identity of people living in South-East Asia, by reducing the amount of carbohydrate they traditionally eat down to Western levels of consumption, we can work with both individuals and the food industry to improve the regions eating habits, and the food supply, to help reduce the risk of developing type 2 diabetes. 

There are a wide range of opportunities and strategies available to reduce the glycemic impact of carbohydrates, whether eaten as a food or in the context of a meal, for both food manufacturers and consumers. Singaporean researchers May Wee and Jeya Henry recently published a comprehensive set of recommendations, which include: 

Using alternative ingredients 

Rice - The common recommendation for a lower GI alternative to white rice (average GI = 78) is brown rice (average GI = 65). There are also white rice varieties that have a lower GI such as Basmati rice (GI = 50). Alternatively, grains with a lower GI than white rice can be used instead, like barley (GI= 29), buckwheat (GI=50), oat (GI= 58), and sorghum (GI=54). 

Flour - A large variety of Asian foods, snacks, and desserts are made from rice, glutinous rice, and wheat flours, and have a high GI. One strategy to reduce the glycemic impact of these traditional flour-based products is to use alternative flours extracted from seeds, grains, nuts, fruits, or tubers of other plants that have a lower GI. For example, buckwheat flour is commonly used in Japan and Korea to make buckwheat noodles (soba; GI = 56). 

Using functional ingredients 

Dietary fibres – Using viscous dietary fibres like agar, alginate, β-glucan, guar gum, konjac, psyllium and xanthan gum will lower the glycemic impact of foods. They can be relatively easily added to foods by food industry. Psyllium can be purchased in supermarkets and some specialty stores and can be added to foods by consumers. 

Changing processing methods and parameters for the food 

Without using alternative ingredients or adding functional ingredients, it is possible to manipulate the structure of the starch-containing food and its subsequent digestibility via processing methods and conditions. 

The main parameters that affect the GI of starchy carbohydrates are cooking temperature/time, amount of water, and cooling temperature/time (storage conditions). All of these can be modified to influence their digestibility and therefore the GI. For example: 

1. Do not overcook grain’s – serve them when they are al dente, like pasta; 
2. Par boil rice and other grains in a minimal amount of water; 
3. Cook then cool higher GI starchy foods like rice and potatoes before eating. Serve either cold or reheat. 

These simple changes will result in lower postprandial (after meal) blood glucose. 

Of course, there is no one-size-fits-all strategy. Ultimately, the effectiveness of the strategy will depend on how well the new textural and sensorial qualities of the food are accepted by people, whether glycemic impact can be covertly reduced for minimal dietary habit change, how compatible the strategy is with an existing food product, and how economically or technologically feasible it is to apply the strategy. 

Read more: 

• Wee and Henry. Reducing the glycemic impact of carbohydrates on foods and meals: Strategies for the food industry and consumers with special focus on Asia

Alan Barclay, PhD is a consultant dietitian and chef (Cert III). He worked for Diabetes Australia (NSW) from 1998–2014 . He is author/co-author of nearly 40 scientific publications, and author/co-author of  The good Carbs Cookbook (Murdoch Books), Reversing Diabetes (Murdoch Books), The Low GI Diet: Managing Type 2 Diabetes (Hachette Australia) and The Ultimate Guide to Sugars and Sweeteners (The Experiment, New York).
Contact: You can follow him on Twitter, LinkedIn or check out his website.

YOUR GI SHOPPING GUIDE

NON-WESTERN BREADS 

One food that unites many cultures across the world is bread. Traditionally made fresh every day, bread represents a carbohydrate-rich staple to fuel the brain and body. In keeping with this month’s focus on non-western foods, we take a look at the GI of some different varieties of bread and the cereal grains they are made from. 

   

Arepa
base cereal: corn, GI 55
A flat, round, unleavened patty originating from Columbia and Venezuela. They are made from pre-cooked ground cornmeal flour. 

Serving: 1 arepa (98g/3 ½ oz)
 

Bagel
base cereal: wheat, GI 70
A ring-shaped, yeasted wheat dough that originated in Poland. The dough is boiled before baking to give a dense, chewy texture. 

Serving: 1 bagel (55g/2oz)

Chapatti / Roti
Base flour: chickpea GI 28
Base flour: millet GI 57 average
Base flour: barley GI 43 average
Base flour: wheat GI 60 average
Base flour: maize GI 63 average

An unleavened flatbread made from flour, salt and water. Most often made with wheat flour, the GI is lower if barley or gram flour is used. It is a staple throughout the Indian subcontinent, East Africa and the Arabian Peninsula. 

Serving: 1 wheat flour chapatti (42g/1½ oz)

Lompe
base flour: wheat (spelt) + potato (pre-cooked and cooled), GI 63 

A soft, Norwegian flatbread, made with boiled potatoes, flour and salt and cooked on a dry griddle. 

Serving: 1 lompe (42g/1½ oz)

Naan
Base flour: wheat GI 71
Dry-baked, leavened flatbread; dough may include yoghurt and ghee or oil 

Serving: ½ large naan (80g/6oz)

Paratha
Base flour: wheat GI 53
Base flour: chickpea GI 40 

A fried, unleavened flatbread, made flaky by layering the dough with oil or ghee. Typically made with wheat flour, it is native to the Indian subcontinent. 

Serving: 1 paratha (130g/4½oz)

Pita bread
Base cereal: wheat flour, GI 65 

A yeast-leavened, flat bread, typically made with white or whole wheat flour, originating in the Middle East. 

Serving: 1 large pita (60g/2oz)

Tortilla
Base cereal - white corn, GI 50 

Thin, flat unleavened flatbread, originally made with cornmeal but now also made with wheat flour. Serving: 1 tortilla (40g/1⅓oz)

Youtiao
Base cereal: wheat, GI 55 

Deep-fried bread stick, commonly eaten in China and other South east Asian cuisines. 

Serving: 1 bread stick (70g/2½oz)

Read more: 

• Foster-Powell and colleagues. American Journal of Clinical Nutrition. In Press. 2021 

Kaye Foster-Powell is an Accredited Practising Dietitian who has worked with people with diabetes for 30 years. She was co-author of the original series of international, best-selling books on the glycemic index. She conducts a specialized private practice for people with diabetes in the Blue Mountains, west of Sydney, Australia.  
Contact: Via her website.

GOOD CARBS FOOD FACTS

When I first saw a dosa being brought to a neighbouring table at an Indian restaurant, I was both surprised and intrigued by its appearance and how it would be eaten. It is certainly a spectacular food, but it’s also fun to eat. You simply break pieces off and use it to scoop up mouthfuls of chutney. 

Dosa originated from Southern India and is a crepe-style very thin pancake made with a fermented batter usually made from rice and lentils (dal), although a variety of grains and legumes may be used including millet and chickpeas. Whole rice and lentils are mixed with water and pureed in a blender/food processor before allowing them to ferment for a day or so in a warm place to grow the natural yeasts and develop the flavour. Some recipes call for fenugreek seeds that add flavour but are also thought to improve digestion. Cheat recipes call for pre-ground rice and lentil flour, even wholewheat flour, and adding lemon juice instead of fermenting the batter. 

Crispness is the name of the game when it comes to cooking dosa, because crispness makes for a stronger scoop. The batter is cooked in an oiled, heavy-based flat pan on moderate heat allowing the dosa to cook and brown gradually. They can then be shaped while still warm and will retain this shape when cool, such as long tube rolls, or like a lampshade (lifted up and fanned out from the middle). However, there is variation in the texture also. Restaurants serve ‘paper dosa’ (like the ones I saw) that are stiff, whereas home cooks generally produce a spongier, softer version. 

Traditionally they are consumed as a breakfast dish, although the rise of Indian street food around the world has blurred the timing and it is consumed at any time of day. 

The nutritional content depends on the ingredients of the batter, and this varies across India and throughout the Indian diaspora. Incorporating legumes with the grains ramps up the overall nutritional value, and using wholegrains increases the fibre content. The ingredients also impact the glycemic index (GI). A new publication has revealed GI values for may traditional non-Western foods, finding GI ratings for dosa are high, moderate or low depending on the ingredients. There may be additional gut health benefits of dosa from the probiotic effect of the fermented batter. 

There’s an art to making dosa at home and practice makes perfect. If you’re not lucky enough to have a dosa expert in your family, do what I do and order it in an Indian restaurant. In fact, there are entire restaurants devoted to this specialty dish. While we can’t travel freely right now, we can support our local restaurants and take a culinary journey instead.   

Source: USDA, 2021 

 
    
Nicole Senior is an Accredited Practising Dietitian, author, consultant, cook and food enthusiast who strives to make sense of nutrition science and delights in making healthy food delicious.    
Contact: You can follow her on Twitter, Facebook, Pinterest, Instagram or check out her website.

THE GOOD CARBS KITCHEN

SOUTH INDIAN PRAWN AND COCONUT CURRY
0:35 Prep • 4 Serves • Main • Every day 

INGREDIENTS
1 medium red onion, chopped
2 garlic cloves, chopped
3cm piece ginger, peeled, chopped
2 long green chillies, chopped, plus extra, to serve
1/2 teaspoon ground turmeric
2 teaspoons ground cumin
2 teaspoons sunflower oil
400g potatoes, peeled, chopped
2 large carrots, cut into rounds
1/2 cup reduced-fat coconut milk
500g peeled green prawns, tails intact
1 large zucchini, halved, thinly sliced
100g baby spinach
2 cups steamed brown basmati rice, to serve 

METHOD
Place onion, garlic, ginger, chilli, turmeric and cumin in a food processor and blitz until a paste. 

Heat oil in a large heavy-based saucepan over medium heat. Add the curry paste and cook, stirring, for 2–3 minutes, or until fragrant. Add potatoes, carrots and 1 cup of water, and bring to the boil. Reduce heat to low and simmer, covered, for 15 minutes, or until potato is nicely tender. 

Add coconut milk, prawns and zucchini, and simmer, uncovered, for 5 minutes. Stir through the spinach until just wilted. Serve with steamed rice and garnish with extra green chilli. 

NUTRITION
Per serve 1730kJ/414 calories; 33g protein; 7g fat (includes 3g saturated fat; saturated : unsaturated fat ratio 0.75); 50g available carbohydrate (includes 9g sugars and 41g starch); 7g fibre; 470mg sodium 

RECIPE AND IMAGE
Courtesy of Australian Healthy Food Guide magazine. 

For more healthy recipe inspiration and expert advice, visit healthyfoodguide.com.au 

CHINESE STYLE BEEF JERKY
0:30–1:00 hr Prep • 0:10 Cook • 12 Servings • Gluten free • Lactose free • Main meal 

INGREDIENTS
Preparation ingredients
1 kilogram of fresh lean beef (e.g., chuck steak, trimmed)
3 large pieces of ginger
2 tablespoons of cooking wine or Chinese rice wine
600ml rice bran oil for wok frying 

Flavouring ingredients
20 g fresh ginger, grated. Alternatively, use ginger powder
2.5 g five-spice powder
10 g salt
3 g Chinese pepper powder
40 ml soy sauce (gluten-free if needs)
1 teaspoon cooking wine
3 g chicken powder
6 g cumin powder
1 tablespoon sesame oil
25 g sugar 

Accompaniments
6 Cups lower GI white rice
12 Cups fresh Asian greens
3 Tablespoons of Oyster sauce 

Sprinkle white sesame seeds for decoration. 

METHOD
Preparation
Add the beef to a pot of cold water, and simmer for 1 hour with all the preparation ingredients. For a quicker recipe, you can use a pressure cooker and cook for ~20 min or until tender. Take the cooked beef out, and cool slightly. Cut the beef into 1 cm x 1 cm x 5 cm pieces. 

Cooking
Fry the beef in a fry pan or wok over the medium heat until brown (~ 3 minutes). Drain the beef from the oil. 

Use another pan or wok. Stir-fry the beef on a low heat with all the flavoring ingredients until they are all mixed (1-2 minutes). 

Steam or boil the rice. 

Steam or boil the Asian greens. 

Serve with white sesame seeds. 

TIPS

• Try plant-based meat for extra protein. Pre-cook the plant-based meat and mix with the rice in the pan for 1-2 minutes. 
• For quick and easy meal, you can use pre-cooked rice instead of raw rice and grains.
  

DID YOU KNOW?
This is a popular Chinese main meal or snack. For a quick and healthier version, you may try to use an air-frier. 

TOO MANY LEFTOVERS?
This can be chilled in the fridge for ~5 days. 

NUTRITION
Per serve 2470 kJ/590 calories; 29.6g protein; 21.2g fat (includes 6.5g saturated fat; saturated: unsaturated fat ratio 0.4); 65g available carbohydrate (includes 6.0g sugars and 59g starch); 7.2g fibre; 892mg sodium; 892mg potassium; sodium: potassium ratio 1.0


Shannon Shanshan Lin is an is an Accredited Practising Dietitian and Credentialled Diabetes Educator with a particular research interest in culturally and linguistically and indigenous populations. She has been actively involved in the various committees both national and internationally, including the Australian Diabetes Educators Association, Global Chinese Diabetes Association and Beijing Key Laboratory of Nutrition Intervention for Chronic Disease. Contact: You can contact her via Wechat (ID= shannon033)

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Nutritional analysis To analyse Australian foods, beverages, processed products and recipes, we use FoodWorks which contains the AusNut and Nuttab databases. If necessary, this is supplemented with data from www.calorieking.com.au or http://ndb.nal.usda.gov/ndb/search.

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