1 March 2021

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. 

Soba

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. 

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Dr Alan Barclay
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.