GI News—February 2013

• Jamie’s low GI 15-minute pesto spaghetti with lemon steamed fish;  
• Not all refined carbs are high GI; 
• Cooking food ups calorie counts;  
• Why iodine deficiency is such a big problem;  
• Cooking helped to make us human; 
• Why it's time to redefine ‘wholegrains’. 

With another series of MasterChef hitting screens, we thought we would take a look at what’s so good about cooking and how it helped to make us who we are. As Prof Richard Wrangham writes in We Are What We ate: ‘To this day, cooking continues in every known human society. We are biologically adapted to cook food. It’s part of who we are and affects us in every way you can imagine: biologically, anatomically, socially.’

Good cooking, good eating, good health and good reading.

Editor: Philippa Sandall
Web management and design: Alan Barclay, PhD
Contact email (for questions or permission to reproduce stories from this newsletter): info@gisymbol.com for technical problems or faults please contact smb.ginewstech@sydney.edu.au

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Food for Thought

Prof Richard Wrangham on why cooked food provides a lot more energy than eating the same food raw. 


Photograph: Stephanie Mitchell/Harvard News Office

‘Whether we are talking about plants or meat, eating cooked food provides more calories than eating the same food raw. And that means that the calorie counts we’ve grown so used to consulting are routinely wrong. Yet there were signs that cooking did affect the calorie counts of some foods. Starches, for instance, like those in wheat, barley, potatoes, and so on, are composed mostly of two sugar-based molecules, amylopectin and amylose, which, when raw, are tightly packed and inaccessible to digestive enzymes. Studies have found that cooking gelatinizes starch, which means that amylopectin and amylose are released and exposed to enzymes. Thus, cooked starches yield more energy than raw ones.

Rachel Carmody’s mouse study found that when the food was cooked the mice gained more weight (or lost less weight) than when it was raw. Over 40 days, two groups of mice were fed a series of diets that consisted of either meat or sweet potatoes prepared in four ways – raw and whole, raw and pounded, cooked and whole, and cooked and pounded. Over the course of each diet, the researchers tracked changes in the body mass of the mice, controlling for how much they ate and ran on an exercise wheel. The results clearly showed that cooked meat delivered more energy to the mice than raw meat. The same was true for sweet potatoes. In both foods, the energy gains from cooking were greater than those from pounding, and cooking increased the energy gained from pre-pounded foods. Preference tests also revealed that hungry mice strongly preferred cooked foods suggesting that the energetic benefits of a cooked diet were obvious to the subjects (i.e. the mice) themselves.

We suspect that there are two major reasons for cooked beef providing more calories than raw beef. In cooked beef, the muscle proteins, like the carbs in cooked starch, have opened up and allowed digestive enzymes to attack their amino acid chains. Cooking also does this for collagen, a protein that makes meat difficult to chew because it forms the connective tissue wrapped around muscle fibers. However, we do not know the exact mechanisms. What we do know, though, is that the mice had a spontaneous preference for eating cooked meat over raw meat, and their choice made sense, given that they fared better on it.



Mechanism aside, though, what the experiments indicated was some serious discrepancies in how calorie counts are measured. The USA uses the Atwater Convention for assessing calories in food, a century-old system that treats food as being composed of a certain number of components, each of which has a fixed calorie value – such as 4 kcals for a gram of protein, 4 kcals for a gram of carbs, 9 kcals for fats … The system gives a good approximation for foods that are highly digestible and demand very little work by the digestive system, such as candy bars. It is convenient because it produces standardized numbers that everyone can agree on.

But the Atwater Convention has two big flaws. First, it pays no attention to the extent to which food has been processed. For example, it treats grain as the same calorie value whether it is eaten whole or as highly milled flour. But smaller particles are less work to digest, and therefore provide more net energy. Second, it treats foods as equally digestible (meaning, having the same proportion digested) regardless of processing. But cooked foods, as we’ve seen, are more digestible than raw foods.

The bottom line: the more highly processed our foods, the more calories we get out of them. If you want to gain weight, make sure you eat highly processed and well-cooked meals. If you want to lose weight, do the opposite. You can eat the same number of measured calories, but if the foods vary in how finely they have been ground or whether they have been cooked, the calorie counts will not tell you what you want to know.’

Richard Wrangham is a professor in the Department of Human Evolutionary Biology at Harvard University and the author of the MUST-READ Catching Fire: How Cooking Made Us Human.

What’s New?

Why ‘whole grain’ is not always healthy. 
Current standards for classifying foods as ‘whole grain’ are inconsistent and, in some cases, misleading, according to a new study in Public Health Nutrition by Harvard School of Public Health researchers. One of the most widely used industry standards, the Whole Grain Stamp, actually identified grain products that were higher in both added refined sugars and calories than products without the Stamp. ‘Given the significant prevalence of refined grains, starches, and sugars in modern diets, identifying a unified criterion to identify higher quality carbohydrates is a key priority in public health,’ said first author Rebecca Mozaffarian. However, no single standard exists for defining any product as a ‘whole grain’.



For this study, Mozaffarian and colleagues assessed five different (US) industry and government guidelines for whole grain products:

• The Whole Grain Stamp, a packaging symbol for products containing at least 8 grams of whole grains per serving (created by the Whole Grain Council, a non-governmental organization supported by industry dues)
• Any whole grain as the first listed ingredient (recommended by the USDA’s MyPlate and the Food and Drug Administration's Consumer Health Information guide)
• Any whole grain as the first ingredient without added sugars in the first three ingredients (also recommended by USDA’s MyPlate)
• The word ‘whole’ before any grain anywhere in the ingredient list (recommended by USDA’s Dietary Guidelines for Americans 2010)
• The ‘10:1 ratio,’ a ratio of total carbohydrate to fiber of less than 10 to 1, which is approximately the ratio of carbohydrate to fiber in whole wheat flour (recommended by the American Heart Association’s 2020 Goals)

The researchers identified a total of 545 grain products in eight categories: breads, bagels, English muffins, cereals, crackers, cereal bars, granola bars, and chips. They collected nutrition content, ingredient lists, and the presence or absence of the Whole Grain Stamp on product packages from all of these products. They found that grain products with the Whole Grain Stamp, one of the most widely-used front-of-package symbols, were higher in fiber and lower in trans fats, but also contained significantly more sugar and calories compared to products without the Stamp. The three USDA recommended criteria also had mixed performance for identifying healthier grain products. Overall, the American Heart Association's standard (a ratio of total carbohydrate to fiber of around 10:1) proved to be the best indicator of overall healthfulness. Products meeting this ratio were higher in fiber and lower in trans fats, sugar, and sodium, without higher calories than products that did not meet the ratio.

cookingmattersaustralia – Getting kids cooking and eating healthily. 



In 2009 the Hunter Illawarra Kids Challenge Using Parent Support (HIKCUPS ) program, a parent-centred dietary modification and physical activity program for overweight and obese children and their families was merged with an after school cooking club already being run at a NSW Priority Action School in the Hunter/Central Coast region, Australia. This led to the creation of the Back to Basics Healthy Lifestyle Program – an evidence-based, family focused, healthy lifestyle program with an after-school cooking club for children that aims to:

• Increase children’s and their families dietary intake of fruit and vegetables 
• Increase children’s and their families awareness and familiarity of healthy eating, with a particular focus on fruits and vegetables 
• Increase children’s skills and confidence in selecting, preparing and cooking fruits and vegetables 
• Increase environmental support for easier access to fruits and vegetables for children and their families 
• Increase children’s self efficacy (belief in their abilities). 

The program, which has been developed by Professor Clare Collins and colleagues from the School of Health Sciences at University of Newcastle, involves five cooking sessions over one school term. The sessions begin with the children’s cooking activities then their parents attend for the final half hour. Finally, parents and children enjoy the prepared meal together. The program has been funded by Hunter Medical Research Institute (HMRI), Newcastle Permanent Charitable Foundation (for B2B development) and Medibank Community Fund (for program dissemination). For more information about the program or if you are interested in running this program at your school contact Clare and her team through the website.

Get the Scoop

The scoop on redefining wholegrains with Prof Jennie Brand-Miller. 



‘Consume more wholegrains is enshrined in dietary guidelines around the globe and has become something of a mantra by doctors, dietitians and nutritionists’ says Prof Jennie Brand-Miller. ‘But does the science stack up to scrutiny? When you see wholegrains on a pack, do you assume it’s the real McCoy? Has it got everything that the original had – all the micronutrients and characteristics that make wholegrains into health foods? Well, I think we are being hoodwinked. Wholegrain products might have started with the germ, the endosperm and the bran of the grain, but often the finished product has been cooked, flaked, toasted, puffed and popped beyond recognition. It’s a long, long way from the grain that came in nature’s packaging.

It’s true that many scientific studies have found that consuming more wholegrains (brown bread, brown rice, brown pasta) is associated with lower risk of cardiovascular disease. For example, the Nurses’ Health Study reported that women who ate wholegrains every day – generally wholegrain breakfast cereals, brown rice and wholewheat bread – were 30% less likely to develop heart disease than women eating merely one serving a week. Unfortunately, studies like this don’t prove that wholegrains are responsible for the good health outcomes. It’s highly likely that people who choose to eat wholegrain foods are unique human beings and health conscious in all sorts of ways. They don’t smoke, they try to be physically active, they eat less red meat and more fruit and vegetables. Of course, good studies will statistically “adjust” for these confounders, as they are called. But I have a niggling feeling that not all the confounders may have been accounted for. Perhaps the person who chooses brown rice over white rice looks after their health in ways that are not yet recorded by researchers eg they eat more slowly, they breathe deeply and they get less stressed.

There are clinical trials in which wholegrains were consumed as one component of a healthy eating pattern (less saturated fat and salt, more fruit, vegies and fibre) but we can’t conclude that the presence of wholegrains were essential for the good outcome. I mention this because there are very few clinical trials that have directly compared a “brown” diet with a “white” diet that was otherwise identical. In the largest clinical trial of its sort to date, UK researchers found that when they provided 316 overweight men and women with a range of wholegrain foods and asked them to substitute them “like for like” for refined grain foods in their typical diet over a 16 week period, there was not even a hint of difference in heart risk (cholesterol, triglycerides, insulin sensitivity and a range of common inflammatory markers) between those who substituted wholegrain foods into their diet, and those who didn’t (the control group). Rather than substitute wholegrains for refined grains, the people actually ate the wholegrains as well as the refined grains, and the authors postulated that this may be the way that the average person interprets dietary guidelines that simply advise people to eat more wholegrains (and not cut back on refined grains). This study should have sounded a note of caution about health claims for wholegrain-rich foods and cardiovascular health ... but it still hasn’t.

More recently, an editorial in a scientific journal extolled the virtues of wholegrains and the dangers of refined grains. Yet the editorial was actually prompted by a new study that found that replacing saturated fat with carbohydrates with high-glycemic index (GI) values was associated with increased future risk of myocardial infarction in a cohort of Danish men and women. In contrast, replacing saturated fat with carbohydrates with low GI values appeared to be protective. The editorialist, however, equated high GI carbohydrates with refined carbohydrates and sugar. Unfortunately, this is unscientific, wishful thinking. The reality is that for most cereal products today, both the “white” version and the “brown” version have a high GI. Nor is it correct to imply that low GI carbohydrates are less processed and refined. Nearly all kinds of white pasta have a low GI, as do some varieties of white rice, canned legumes, fruit juices, dairy products (sweetened or otherwise), and many confectionery items containing refined sugars. Thus many low GI foods are “processed” products. Nonetheless, low GI and low glycemic load diets have been associated with good health outcomes in scores of observational studies and clinical trials. What’s more, the “health bias” that accompanies diet rich in wholegrain foods is absent because the GI is still a term that means little to many.

For all these reasons, I’d like to suggest that we re-define wholegrains as “foods that not only contain the germ, the endosperm and the bran, but also the GI characteristics of the original grain.” At least then, we might see some real benefits of eating wholegrains. In the meantime, here are some of my favourite low GI wholegrain foods that are easy to find in your supermarket:

• Bulgur 
• Pearl barley 
• Low GI brown rice – there are even speedy 2-minute microwave options including brown basmati 
• Wholemeal/wholewheat spaghetti and pasta shapes.’

In the GI News Kitchen

American dietitian and author of Good Carbs, Bad Carbs, Johanna Burani, shares favourite recipes with a low or moderate GI from her Italian kitchen. For more information, check out Johanna's website. The photographs are by Sergio Burani. His food, travel and wine photography website is photosbysergio.com.



Tiziana’s roasted peppers.  
Tiziana is my amazing sister-in-law. I won’t divulge her age but suffice it to say that, if she lived here in the US, her Medicare card would long be rumpled and weather beaten. Her body is riddled with arthritis but you’d never know it. She keeps a pristine house, helps in her husband’s fresh produce store, watches grandchildren, family and stray pets and cooks fabulous meals in a flash. We spent some time visiting Tiziana and her husband, William, recently in their northern Italian home. The recipe below is just one of the scrumptious dishes she served us. Buon appetito! Serves approximately 6 (5 strips per person)

4 large peppers (yellow, orange or red not green)
1/3 cup water
¼ tsp salt
1–2 cloves garlic, finely minced
1½ tbsp extra virgin olive oil (1 Australian tbsp)
4 tsp seasoned breadcrumbs
1 tbsp finely chopped fresh parsley



Preheat oven to 400ºF (200ºC).
Wash and dry the peppers. Cut off tops, remove seeds and internal membranes. Slice into eighths. Place pepper strips in a 9in x11in (23 cm x 28 cm) roasting pan.
Briskly whisk together water, salt, garlic and oil in a small bowl and spoon over peppers. Top with breadcrumbs. Roast for 25–30 minutes. Remove from oven, sprinkle over the parsley and serve hot.

Per serve
315kJ/75 calories; 2g protein; 5g fat (includes less than 1g saturated fat); 47g available carbs; 1g fibre

Here's how you can cut back on the food bills and enjoy fresh-tasting, easily prepared, seasonal, satisfying and delicious low or moderate GI meals that don’t compromise on quality and flavour one little bit with our Money Saving Meals including these delicious fish cakes from FISHline, Sydney Fish Market's free consumer advisory service.

Sweet potato fish cakes with dill sauce. 
Fish cakes are a great way to use up leftovers.  Substitute redfish, silver warehou, pink ling, jackass morwong or one of the dories if you can't buy ribaldo or ask for the day’s best buy that will make good fish cakes. Makes 12 patties.

450g (1lb) orange-fleshed sweet potato
600g (1lb 5oz) ribaldo fillets, skin off
 ⅔ cup chopped flat-leaf parsley
2 spring onions, thinly sliced
few drops Tabasco
 ½ cup plain flour
2 eggs, lightly beaten
2 cups fresh breadcrumbs (made with stale bread)
½ cup olive oil
3 cups baby rocket, to serve (or more rocket to taste)
1 tbsp lemon juice, to serve

Dill sauce
1 cup natural yoghurt
 ½ cup whole-egg mayonnaise
¼ cup lemon juice
2 tbsp chopped dill



Peel and dice sweet potato and steam until tender. Mash until smooth.
Cut fish into large chunks, pulse in a food processor, in 2 batches if necessary, until coarsely chopped. Combine well with sweet potato, parsley, shallots and Tabasco and season to taste with salt and pepper.
Wet hands and divide mixture into 12 patties. Flatten slightly and lightly dust with flour, dip in beaten egg and then in breadcrumbs. Place on a plate, cover and refrigerate for 30 minutes. Meanwhile make the dill sauce: whisk all ingredients together.
Heat a frying pan over medium heat, add ¾ of the oil and, when hot, add fish cakes and cook each side for about 3 minutes, until golden and cooked through. Drain on paper towel.
Toss rocket with remaining oil, lemon juice, salt and pepper and mound in the centre of plates, place fish cakes on top and drizzle with dill sauce. Pass the remaining sauce separately.

Visit the FISHline for more seafood recipes, advice on seafood purchasing, storage and cooking, species information and answers to frequently asked seafood questions.

Per pattie
1330 kJ/320 calories; 16g protein; 16g fat (includes 3g saturated fat); 27g available carbs; 2.5g fibre; 300mg sodium

Jamie’s 15 Minute Meals. 
The cover describes the recipes in this book as ‘delicious,’ ‘nutritious’ and ‘super-fast’. And they are. We particularly like the fact that many are also low. Check out www.jamieoliver.com for more information.

Pesto spaghetti/lemon-steamed fish. 
Serves 4

200g (7oz) large scallops
400g (14oz) white fish fillets, scaled and pin-boned
olive oil
1 lemon
½ a dried red chilli

Pasta
320g (11oz) dried spaghetti
200g (7oz) green beans
200g (7oz) purple sprouting broccoli

Pesto
75g (2½oz) blanched almonds
1 big bunch of fresh basil
1 clove of garlic
 tbsp extra virgin olive oil (1½ Australian tbsp)
50g (1½oz) Parmesan cheese
1 lemon


Photography © David Loftus, 2012

 Ingredients out • Kettle boiled •Wok or large pan, medium heat • Large lidded pan, medium heat • Food processor (bowl blade) •Two 25cm (10in) bamboo steamers 

Score the scallops on one side in deep criss-crosses • Pour 2.5cm (1in) of boiling water into the wok or large pan • Pour the rest of the water into the other pan, add the spaghetti and a pinch of salt and cook according to packet instructions • Put the almonds into the processor, rip in most of the basil leaves and squash in the unpeeled garlic through a garlic crusher • Add the extra virgin olive oil, Parmesan and the juice from ½ a lemon, blitz until smooth, then season to taste and check the balance of flavours – it should be clean and refreshing
Line the beans up and cut off the stalks, then add to the pasta pan • Put one of the steamers into the wok and add the trimmed broccoli, then put the second steamer on top • Rub the fish and scallops with a pinch of salt and pepper and lay in the second steamer • Drizzle with 1 tablespoon of olive oil, finely grate over the zest of a lemon and squeeze over half the juice, then crumble over the chilli and put the steamer lid on until cooked through
Drain the pasta and beans, reserving a cupful of the starchy cooking water, then return them to the pan • Spoon in the pesto from the processor and toss together, loosening with splashes of the cooking water until silky • Squeeze in lemon juice to taste, then pour into a serving bowl with the broccoli • Sprinkle over the remaining basil leaves and serve alongside the steamer basket of fish.

Per serve 
3080 kJ/735 calories; 47g protein; 32g fat (includes 7.2g saturated fat); 59g available carbs; 10.5g fibre; 510 mg sodium.


Jamie’s 15 Minute Meals is published by Michael Joseph, Penguin and is available in good bookshops and online.

We Are What We Ate

How cooking helped to make us human. 



‘You are what you eat.’ Can these pithy words explain the evolution of the human species? Yes, says Richard Wrangham of Harvard University, who argues in his book, Catching Fire, that the invention of cooking – even more than agriculture, the eating of meat, or the advent of tools – is what led to the rise of humanity. In it, he makes the case that the ability to harness fire and cook food allowed the brain to grow and the digestive tract to shrink, giving rise to our ancestor Homo erectus some 1.8 million years ago. ‘It’s hard to imagine the leap to Homo erectus without cooking’s nutritional benefits,’ says Richard Wrangham. ‘Cooking is the signature feature of the human diet, and indeed, of human life – but we have no idea why. ‘It’s the development that underpins many other changes that have made humans so distinct from other species.’

Drawing on a wide body of research, he makes the case that cooking makes eating faster and easier, and wrings more caloric benefit from food. Moreover, he writes, cooking is vitally important to supporting the outsize human brain, which consumes a quarter of the body’s energy. By freeing humans from having to spend half the day chewing tough raw food — as most of our primate relatives do – cooking allowed early humans to devote themselves to more productive activities, ultimately allowing the development of tools, agriculture, and social networks. Cooked food is also softer, meaning the body uses less energy digesting what it takes in.

Since physical remnants of fire tend to degrade rapidly, archaeological evidence of fire and cooking dates back only about 800,000 years. Wrangham looked to biological evidence, which shows that around 1.8 million years ago, Homo erectus arose with larger brains and bodies and smaller guts, jaws, and teeth – changes consistent with the switch to a more tender and energetically rich diet of cooked food. ‘Cooking is what makes the human diet ‘human,’ and the most logical explanation for the advances in brain and body size over our ape ancestors,’ Wrangham says. ‘It’s hard to imagine the leap to Homo erectus without cooking’s nutritional benefits.’

While others have posited that meat-eating enabled the rise of Homo erectus some 1.8 million years ago, Wrangham says those theories don’t mesh with that species’ smaller jaws and teeth. Instead, he claims meat enabled the shift from australopithecines to Homo habilis – a species about the size of a chimp, but with a bigger brain – more than half a million years earlier. Wrangham says the adoption of cooking had profound impacts on human families and relationships, making hearth and home central to humanity and driving humans into paired mating and perhaps even traditional male-female household roles.

He writes that the advent of cooking permitted a new distribution of labor between men and women: Men entered into relationships to have someone to cook for them, freeing them up for socializing and other pursuits and bolstering their social standing. Women benefited from men’s protection, safeguarding their food from thieves. Homo sapiens remains the only species in which theft of food is uncommon even when it would be easy.

‘To this day, cooking continues in every known human society,’ Wrangham says. ‘We are biologically adapted to cook food. It’s part of who we are and affects us in every way you can imagine: biologically, anatomically, socially.’

Source: This article by Steve Bradt first appeared in Harvard Science and is reprinted in GI News with the kind permission of Professor Wrangham and Harvard Gazette.

GI Symbol News with Dr Alan Barclay

Dr Alan Barclay

Not all refined carbs are high GI.
Despite frequently being used interchangeably in the media and scientific reports ‘refined carbohydrate’ and ‘high GI’ are not the same thing. In fact using them as if they were may have adverse effects on some people’s health as some refined carb foods (like pasta) have a low GI and some ‘whole’ and unprocessed foods like most potatoes have a high one. Simply recommending we eat ‘less-refined foods’ is not enough to help people prevent and manage weight gain or type 2 diabetes.

While refining and/or processing may modify the overall GI of a food, it doesn’t necessarily mean the final product will have a higher GI – it all depends on the GI values of the sugars and starches in the actual foods and how the foods have been refined and/or processed. The following examples illustrate how.

Sugary foods The GI of sugars ranges from 15 for fructose to 105 for maltose – a seven-fold difference! Most fruit-based products (dried and canned fruit and fruit juices) and dairy foods have a low GI, because the predominant carbohydrate in these products (e.g., fructose and lactose/GI = 46) are low GI. On the other hand, most ‘foods/beverages’ like confectionery and soft drinks made primarily from table sugar (or sucrose/GI = 65) will have a medium GI – not a high GI as is often assumed. Of course, unlike fruit and dairy foods, soft drinks and confectionery are occasional TREATS (not everyday foods) even if the balance of sugars were changed to lower their GI, they would still remain treat foods. 

Starchy foods Unlike sugary foods, the type of starch contained in a food is not as strong a predictor of its GI for a variety of reasons. There are two main types of starch – amylose and amylopectin, with amylose having a lower GI than amylopectin. So a food with more amylose may have a lower GI than one higher in amylopectin, but this is not always the case. This is partly because the starches in unrefined grains like hulled barley, brown rice or wheat berries are encapsulated by the germ and bran, which when left intact can make the starch - regardless of type - very hard to digest. Of course, this is why we process them to provide us with more digestible forms (e.g. pearl barley, white rice and bulgur) or into flour. We have found that the milling method (e.g., stone grinding versus modern steel roller milling) generally has a more significant effect on the ultimate GI of grain foods. Traditionally stone ground flours retain much more of the germ and bran and have more coarsely ground endosperm (where the starch is found), so the starch is still much harder to digest than modern roller-milled grains. You can see an example of 'traditional' stone milling to make tortillas in this 10-minute movie Maiz made in around 1960 by Roger Sandall in Mexico.


Photo by Sheridan Rogers: www.sheridanrogers.com.au

Breads do not always have a high GI although the main ingredient (flour) is usually a highly refined starch. This is because other aspects of the bread making process affect the GI. Gluten matrices form in flour after it is mixed with water and kneaded into a dough – gluten encapsulates the starch molecules making them harder to digest. In addition, the organic acids that form when the dough rises can lower the pH of the final product – organic acids slow digestion and absorption of carbohydrates, further lowering their GI. This is why authentic sourdough breads made the traditional way (in which lactic acid and propionic acid are produced by the natural fermentation of the starches and sugars by the bacterial starter culture) have a much lower GI (54–58 ) than most sandwich breads (average 71) on supermarket shelves. Both use refined flour, but the method of processing has a significant effect on  their GI.

What do we recommend? Reduce your intake of carb-rich foods with ‘added refined sugars’ and ‘added refined starches’, particularly those with a high GI and join us in pushing for a dietary guideline for breads and cereals that looks something like this: ‘Eat plenty of cereals, breads and pastas — preferably wholegrain with a lower glycemic index’.  

The GI Symbol, making healthy low GI choices easy choices



For more information about the GI Symbol Program
Dr Alan W Barclay, PhD
Chief Scientific Officer
Glycemic Index Foundation (Ltd)
Phone: +61 (0)2 9785 1037
Mob: +61 (0)416 111 046
Fax: +61 (0)2 9785 1037
Email: alan.barclay@gisymbol.com
Website: www.gisymbol.com

GI Update with Prof Jennie Brand-Miller

Prof Jennie Brand-Miller answers your questions. 



I read an article in the Sydney Morning Herald suggesting iodine deficiency could be why Australian children lag behind at school. Can you tell me more about iodine and how much we need and where we can get it naturally. 
Iodine is a naturally occurring mineral that is needed by the thyroid gland in order to synthesize thyroxine, an important hormone that regulates metabolism. In babies and young children, thyroid hormones play a key role in physical and mental development. A deficiency of iodine can lead to learning difficulties and affect physical development and hearing. The recommended dietary intake a day for iodine is 150 micrograms for most adults, but this increases to 220 micrograms during pregnancy and 270 micrograms while breast-feeding, as your baby will take the iodine it needs from you.

Iodine deficiency Because Australian and New Zealand soils are low in iodine, the National Health and Medical Research Council and the New Zealand Ministry of Health recommend that all women who are pregnant, breastfeeding or considering pregnancy, take an iodine supplement. However, it’s best to speak with your doctor before taking a supplement, especially if you have a pre-existing thyroid condition.

Though iodine deficiency is not typically a problem in the United States, as most table salt is enriched with iodine, the American Thyroid Association recommends that all women who are pregnant, breast-feeding, or considering pregnancy take an iodine supplement of 150 micrograms each day. Kelp and seaweed supplements are not recommended as they contain varying amounts of iodine and can even cause toxicity (too much iodine). Again, speak with your doctor first.

Best natural sources of iodine The best source of iodine in our diet is seafood. We also get iodine from other foods including milk and vegetables, but the amount varies depending on how these foods are grown and processed. In Australia and New Zealand, all salt used for making bread (apart from organic breads) must now be iodised, so bread has become a source of iodine. While we don’t recommend that you add salt to your food, if you use it in cooking (for example, when boiling rice or pasta), it’s best to buy iodized salt and use sparingly, particularly if you don’t regularly consume other iodine-rich foods. Another tip I learned lately was that iodized salt has a use-by date because it loses the iodine gradually to the air (vaporisation). If you use the large SAXA containers as I do, but only a little, it might be years before it’s empty. So check the use-by date … you may need to bin it if you have had it in the cupboard for a long while!

 

Four tips for increasing your iodine intake 
1. Include a few meals of fish or seafood each week (there are two fish recipes in this issue of GI News for starters to try).
2. A glass of milk or container of yogurt with cereal or as a snack will provide iodine as well as calcium and other nutrients.
3. If you use salt in cooking or on your meals, choose iodized salt rather than other types.
4. Sushi is a good way to get iodine, but for food safety reasons needs to be homemade (without raw fish) and eaten fresh. Nori (sushi wrappers) can also be chopped into salads and stir-fries for vegetarians or non-fish eaters, but avoid kelp, which can contain very large amounts of iodine.

This is an edited extract from my latest book (with Dr Kate Marsh and Prof Robert Moses), The Bump to Baby Low GI Eating Plan for Conception, Pregnancy and Beyond (Hachette Australia) which is available from good bookshops and online. You can also visit us HERE. We are delighted to let GI News readers know that a US edition is well on the way (we have just checked the page proofs). The publisher is Matthew Lore of The Experiment. Matthew has published many of our books in the past and we are absolutely delighted to be working with him on this. We will keep you posted re the publication date.



GI testing by an accredited laboratory
North America
Dr Alexandra Jenkins
Glycemic Index Laboratories
20 Victoria Street, Suite 300
Toronto, Ontario M5C 298 Canada
Phone +1 416 861 0506
Email info@gilabs.com
Web www.gilabs.com

Australia
Fiona Atkinson
Research Manager, Sydney University Glycemic Index Research Service (SUGiRS)
Human Nutrition Unit, School of Molecular and Microbial Biosciences
Sydney University
NSW 2006 Australia
Phone + 61 2 9351 6018
Fax: + 61 2 9351 6022
Email sugirs@mmb.usyd.edu.au
Web www.glycemicindex.com

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