1 February 2008

GI News—February 2008


In this issue of GI News

  • Debunking the carrot myth
  • The blood-glucose-reducing pucker power of vinegar
  • The Low GI Family Cookbook hits the stands
  • Are chia seeds a magic food?
  • Exercise builds brain health
  • What’s on the menu when it comes to food for love?
We have the power to change the shape of things to come says Dr David Ludwig in his column this month. With time for physical education classes for our kids being gobbled up by other academic demands, he shares the story of how one inspirational teacher, Patty Nolan of Warren Point Elementary School in Fair Lawn New Jersey, took matters into her own hands and made a real difference to the children and families of her community. Also this month our chef Kate Hemphill has more fabulous fare including a Mango, passion fruit and lime fruit salad that your editor has made several times this summer already and Hermin Halim sorts fact from fiction in the GI or GL question.

Good eating, good health and good reading.


GI News Editor: Philippa Sandall
Web Design and Management: Scott Dickinson, PhD

Food for Thought

Debunking the carrot myth
Raw or cooked, carrots are good for you and they won’t send your blood glucose on a roller coaster ride. End of story. Why? Well, not only are they a low GI food (41), they have very few carbs. In fact, to get a hefty portion of carbs from carrots you’d have to crunch through at least 5 cups or 750 g (about 1½ lb) at a sitting – a pretty awesome achievement even for carrot lovers.


How did the high GI carrot myth happen. Well, they were first tested way back in the early days (1981) – only five people were included in the study, the variation among them was huge, the reference food was tested only once and the result was a high GI. And it was that early high GI result for healthy foods like carrots (along with watermelon) that became the stick to beat the whole GI concept with for years – and to this day for the anti-GI stalwarts.

By the 1990s, international standardised procedures producing really reliable results for GI testing were clearly established and the SUGiRS team decided to retest carrots. This time, ten people were included and the reference food was tested twice as per the standardised methodology for GI testing. The result was a mean GI value of 41 with a very narrow variation. Although this later and clearly more accurate value for carrots was published in the International Tables of GI Values (2001), the word just didn’t seem to get around. To this day, GI opponents still clobber us and the GI concept with the old value for carrots. Lesson: you can’t win ’em all. Lesson two: ‘A food’s GI value was never meant to offer the only criterion by which it is judged as fit to eat’ says Jennie Brand-Miller in The New Glucose Revolution. It’s a useful tool from the nutrition tool box to help you choose more of those smart carbs when creating a healthy eating plan.

So if carrots don’t have many carbs, how many did you make your volunteers crunch to get the GI value,’ a reader asked us recently? When we test any food, we calculate how much food we need to provide 50 grams of digestible carbohydrate (fibre’s not counted in this). If this represents an unreasonably large amount of food for anyone to eat, we scale down everything by half and test a 25 gram carbohydrate portion. In fact, MOST fruits and vegetables and some dairy products have been tested this way. In the case of carrots, our volunteers ended up eating about 350 g cooked carrots (3–4 large carrots). It was a big portion but manageable! In the case of raw carrot juice (GI 43), they drank 350 ml or just under 1½ cups (easy!). So what’s the take-home message? Well, because all fruits and vegetables are valuable additions to the diet, don’t dwell on their GI. With the exception of potatoes which are carb rich and have a high GI for the most part, tuck in to your heart’s content to make sure you get those 2 serves of fruit and 5 of veggies every day along with the fabulous fibre these healthful foods provide.

For a carrot recipe with the right amount of crunch for this piece we turned to Julie Daniluk, Toronto’s Big Carrot’s chief in-store nutritionist. You don’t need to peel the veggies and fruit, just wash and scrub them well before grating or chopping. Julie tells us that you ‘can make it ahead of time and store in the fridge if you prefer to give the flavours time to blend.’ She also recommends adding a clove of fresh chopped garlic as a booster.

Julie Daniluk’s Carrot and Beetroot Salad
Serves 4 as a side salad


2 cups roughly chopped romaine (cos) lettuce or your favourite salad greens
1 crisp green apple, washed but not peeled
2 medium carrots, scrubbed (or peeled) and grated
1 medium beetroot, scrubbed (or peeled) and grated
50 g (2 oz) natural almonds, halved or roughly chopped
2 tablespoons (30 ml) lemon juice
2 tablespoons (30 ml) olive oil

  1. Line a large serving platter with the lettuce or salad greens. Chop the apple into 1 cm (½ inch) cubes and brush with lemon juice to prevent browning.
  2. Combine the grated carrots, beetroot, chopped almonds and apple in a bowl and toss with the olive oil. Assemble this bright red and orange root veggie salad on top of the greens and enjoy.

News Briefs

Lower GI diet cuts inflammation even in well-controlled diabetes
One hundred and sixty two adults with well-managed diabetes took part in a Canadian study reported in AJCN (January 2008) to see if a low GI diet could offer any additional benefits. The authors found that the best measure of blood glucose control (glycated hemoglobin or A1c) showed no further improvement but C-reative protein levels (CRP – a protein produced in the liver and reportedly a good predictor of the onset of cardiovascular disease) was 30% less in those on a lower GI diet compared with those on two other healthy diets. That spells less inflammation and therefore lower risk of all diseases with an inflammatory component, including heart disease and osteoarthritis.


The researchers set out to compare the effects of changing carb quality (its GI) and carb quantity in managing type 2 diabetes. At the outset of the year-long trial, all the participants already had optimal glycemic control by diet alone (HbA1C 6.0–7.0). After 12 months, the researchers report that while long-term HbA1C was not affected by either the quality or quantity of carb in the diets, two hour post-meal glucose levels and CRP were significantly reduced in those on the lower GI diet.

GI Group: This study is one of the best of its kind, but what a pity the authors recruited subjects who were so well controlled that further improvements were unlikely. If we want to nit-pick, we could say that what the authors called 'the low GI diet' is not really a low GI diet at all. Its GI of 55 is not much lower than what the average person in the developed world eats right now (i.e. the average diet has a GI of 54–58, glucose = 100). What we now know from observational/cohort studies is that the GI of the diet of the people in the lowest quintile (20% of the population) is about 40–45. Similarly, the randomised controlled trials that have shown positive affects of low GI diets on the management of existing diabetes also have an average GI of around 45. Therefore, you need to lower the average GI of the diet to these levels to see a reduction in the risk of chronic diseases like diabetes and heart disease, and to see significant improvements in their management. It’s achievable. How?

Substitute low for high GI foods in your everyday meals and snacks, especially in the breads and cereals you choose. Breakfast in particular is your opportunity to go for gold by selecting a low GI breakfast cereal. Don't assume that adding milk to crispy flakes makes it a low GI meal. If you don’t eat breakfast cereal, make sure you choose a low GI bread for your toast, and of course low GI breads are a must for those sandwiches at lunch.

6 healthy habits made easy
Should you be eating more of this or doing more of that for your long-term health and wellbeing? Japanese researchers have come up with a handy way to remember 6 key health habits to reduce your risk of metabolic syndrome. Just think ‘none of 1, less of 2, more of 3.’


The researchers tested these 6 healthy habits with over 18,000 people who attended the Health Science Centre at Jikei University in Tokyo and found that those who practised more of these 6 health habits had less risk factors of metabolic syndrome (high blood pressure, high blood glucose, high blood fats and abdominal obesity). Here are the stats: 7% of those practising all 6 habits had no metabolic syndrome symptoms; of the people who did not practise any of the healthy habits, 20% had metabolic syndrome symptoms.
Obesity Research and Clinical Practice, Vol 1, Issue 2, May 2007.

Seeds of success
Salba® (the trade name of a variety of white chia seeds cultivated through selective plant breeding) may help regulate blood pressure and other risk factors for heart disease in people with diabetes report Canadian researchers in November 2007 Diabetes Care. Dr Vladamir Vuksan and a team at Toronto’s St Michael's Hospital in a single blind cross-over study assigned 20 otherwise healthy adults with well controlled diabetes to supplement their diet with Salba (or wheat bran as the control) for 12 weeks while maintaining their standard diabetes treatments. The Salba seeds were ground into flour and served in bread made by the team or sprinkled on food. Their total intake was approximately 37 grams or 3–4 tablespoons of Salba a day. Compared with the control, the Salba reduced systolic blood pressure, on average, by 6 points mmHg, reduced low grade body inflammation (as measured by C-reactive protein) and made blood thinner and less prone to clotting. There were no changes in body weight.


‘Salba seems to possess important cardio-protective properties in type 2 diabetes by reducing conventional and emerging heart disease risk factors that are associated with diabetes’ said Dr Vladimir Vuksan, research-scientist at the Keenan Research Centre of the Li Ka Shing Knowledge Institute of St. Michael's Hospital and professor in the faculty of medicine, University of Toronto. ‘It is an exceptionally rich source of vegetable protein, calcium, magnesium and iron, with antioxidant levels higher than in some berries. Simple addition of Salba to one’s diet not only helps patients reach their target treatment goal but also allows patients to take their health into their own hands to improve their diet and health outcomes.’ While the study found no ill effects, Vuksan cautions that, because of Salba's ability to thin blood, anyone on anticoagulants, blood thinners other blood pressure medications should consult with their doctors before taking it.

You can eat the seeds raw or use ground seeds in baked goods such as breads, cakes and biscuits or made into a porridge. Soaked seeds make a rather gelatinous drink – Mexico’s chia fresca is chia seeds soaked in fruit juice. A number of websites have recipes. But remember, cooking with Salba or chia doesn’t necessarily make a recipe a healthy one. And a word of caution before you rush out and invest in a kilo of chia, it’s just a supplement not a magic bullet. You still have to stick with those healthy lifestyle habits described in the previous piece ('6 healthy habits made easy') including eating better (and probably less) and exercising more.

Chia seeds (Salvia hispanica), once a staple food of the Aztecs (along with corn and beans), are the seeds of an annual ‘herb’ from the mint family. Chia is grown commercially today for it is seriously rich in omega-3 seeds – they are currently the highest known plant source of this essential fatty acid. They also have heaps of dietary fibre (mostly insoluble), some protein and virtually no carbs. They are gluten free. GI News readers may be more familiar with chia than they think – those are chia sprouts growing on popular ‘Chia Pets’.
Diabetes Care 30: 2804-2810 and the St. Michael’s Hospital press release & backgrounder.

Cooking boosts nutrients
Steaming broccoli increases its levels of cancer-fighting compounds say scientists from the Universities and Parma and Naples writing in the Journal of Agricultural and Food Chemistry (December 26, 2007).


Looking at the effects of boiling, steaming, and frying on the phytochemical content (polyphenols, carotenoids, glucosinolates and ascorbic acid) of carrots, zucchini (courgettes) and broccoli, they found an overall increase in antioxidant levels after cooking. Boiling and steaming preserved antioxidant compounds better, especially carotenoids in all the veggies and ascorbic acid in carrots and zucchini. Steamed veggies maintained their texture better than boiled ones. There was a higher loss of antioxidants in the fried veggies. ‘Our findings defy the notion that processed vegetables offer lower nutritional quality and also suggest that for each vegetable a preferred cooking method to preserve the nutritional qualities,’ say Nicoletta Pellegrini and colleagues. Download the PDF article.

What's New?

Norene’s Healthy Kitchen
Eat your way to good health with Norene Gilletz (Whitecap). The 600 recipes in the book are heart healthy and suitable for people with diabetes or wanting to lose weight. What’s special about this book compared with so many that come across the editor’s desk is that the recipes are extremely well written with clear guidelines about equipment and cooking times. Nothing is left to chance. There’s also a terrific introductory section covering the glycemic index, quick meal planning tips for people with diabetes, shaking the salt habit, how to grill it right, food safety and cooking/baking substitutions. There are chef’s secrets and variations with many of the recipes and all have a nutritional analysis. Norene Gilletz is a leading authority on kosher cooking, an IACP Certified Culinary Professional and freelance food writer. Her motto is ‘food that’s good for you should taste good.’ We completely agree!


Culinary Solutions Gourmania Inc, Toronto, Canada – ph: (1) 416-226-2466; fax: (1) 416-226-2512

The Low GI Family Cookbook

By Kaye Foster-Powell, Anneka Manning, Jennie Brand-Miller and Philippa Sandall (Hachette Australia).
The US/Canadian edition will be available March 2008.

Parents know that the benefits of healthy eating are enormous, but getting their kids to actually eat healthy foods can be another challenge altogether! Whether you have a toddler or teenager, this book has been written to make it easier for anyone to combine (deliciously) the essentials of healthy eating with the proven benefits of low GI carbs. It’s about parents and children cooking together, eating together and developing healthy eating habits for life say the authors in the introduction. There are over 100 easy-to-prepare recipes for breakfast, lunch, snacks, main meals and sides, desserts and sweet treats packed with healthy, low GI ingredients that the whole family will love.

But that’s not all. The comprehensive introductory section includes 7-day menu plans for pre-schoolers, school age kids and teens, plus tips on raising food-smart kids, everyday healthy eating guidelines, making mealtimes happier, the problem with drinking those kilojoules, treats and takeaways, fuelling active kids, coping with food allergies and intolerances, handling fussy eaters, filling hollow legs and what to do if your child is overweight, or underweight.


Flax, fiber and GI
If you want to learn more about the science and marketing behind GI products as well as the impact that fibre-rich flax has on lowering the GI of products, register for a free Webinar on 28 February HERE.

Get started on one of those six healthy habits mentioned above with FebFast, an Australian community education and awareness campaign that invites people to do something good for their own bodies, and someone else's by sacrificing their alcohol intake for up to one month, during February. Participants are sponsored by friends and family, with funds distributed to organisations that support young people struggling with substance use. Don't be deterred if you are reading this on Feb 2, 3 or 10, the FebFast Team say you can join up anytime. For more information, check out www.febfast.com.au

Are you a young adult living at home
If you are a young adult in your 20s or 30s, still living in the family home (and possibly you don't know much about cooking and less about nutrition), Freehand TV would love to hear from you. They are producing a new TV show for SBS in Australia and looking for families with adult kids that aren't in any rush to move out of the family home. If you're interested in taking part or would like some more information, please email your story and contact details to: casting@freehandtv.com.au OR call Caroline on 02 8514 5431

Food of the Month

Vinegar: More than pucker power
Several research findings over the last decade have shown that having a realistic amount of vinegar or lemon juice in the form of a salad dressing with a mixed meal has significant blood glucose-lowering effects. In fact, as little as 4 teaspoons of vinegar in a vinaigrette dressing (4 teaspoons vinegar + 2 teaspoons oil) with an average meal lowered blood glucose by as much as 30%. We know from our own GI Group research shows that lemon juice is just as powerful. ‘The effect appears to be related to the acidity,’ says Prof Jennie Brand-Miller ‘because some other organic acids (like lactic acid and propionic acid) also have a blood glucose-lowering effect, but the degree of reduction varies with the type of acid.’ How does it do it? Essentially, the acidity puts the brake on stomach emptying, slowing the delivery of food to the small intestine. Digestion of the carbohydrate in the food is therefore slowed and the final result is that blood-glucose levels are significantly lower. Animal studies are also showing that acid may increase the storage of glycogen (the form that blood glucose is stored for future energy needs) in the skeletal muscles and liver, providing fuel for later use.


According to a small preliminary study recently published in Diabetes Care (2007; 30 (11): 2814-2815) downing a couple of tablespoons of apple cider vinegar before bed may help to reduce high fasting blood glucose levels the following morning, in people with type 2 diabetes. Researchers from Arizona State University, gave 11 people with type 2 diabetes, 2 tablespoons of apple cider vinegar as a late night snack with cheese and compared the results with a pre-bed cheese and water snack. They found a small average reduction of 0.26 mmol/L (a 4% decrease) in fasting blood glucose levels with the cheese and vinegar snack compared to a 0.15 mmol/L (2%) reduction for cheese and water. ‘Finding ways to help those with type 2 diabetes maintain acceptable blood glucose through foods and diet patterns is far more appealing for many to manage their condition,’ said Dr Carol Johnston, Department of Nutrition chair. ‘Vinegar is widely available, it is affordable, and it is appealing as a remedy, but much more work is required to determine whether vinegar is a useful adjunct therapy for individuals with diabetes,’ the researchers conclude.

Swedish researchers from Lund University have found another benefit of pucker power – vinegar may also help dieters eat less and reduce cravings brought on by sugar spikes after meals. The more vinegar consumed (up to 2–3 tablespoons before a meal), the more satisfied people felt.

'I have read that the only benefits to be derived from vinegar are if it is "mother vinegar" or raw and unprocessed. Do apple cider vinegar and red wine vinegar have the same effects? '
Yes they do. So will balsamic vinegar and white wine vinegar, lemon juice, lime juice, some salad dressings and even pickled vegetables.

Low GI Recipes of the Month

Our chef Kate Hemphill develops deliciously simple recipes for GI News that showcase seasonal ingredients and make it easy for you to cook healthy, low GI meals and snacks. For more of Kate’s fabulous fare, check out: http://www.lovetocook.co.uk/. For now, prepare and share good food with family and friends.

Kate Hemphill

Mango, passion fruit and lime fruit salad
There’s no need to slave over a hot stove to wow family and friends. This dessert is absolutely delicious and truly made in minutes. Make sure your fruit is ripe and full of flavour. If it is a little under-ripe and the fruit salad tastes too tart you may need to add a little caster sugar. If you can’t get mango puree, substitute by pureeing a small can of mango pieces (without the juice) in the blender. As you only need a scant ½ cup, keep leftovers for your morning muesli.
Serves 2


2 medium ripe mangoes, peeled and cut into dice (about 2 cups mango dice)
2 ripe passion fruit


½ cup (125 ml) mango puree
pinch of ground ginger
1 lime, juiced

  • To make the dressing, combine the mango puree, ginger and lime juice in a small bowl.
  • Place the mango dice into a serving bowl. Scoop out the passionfruit pulp and seeds and add to the mango dice, then gently stir through the mango-lime dressing.
Per serve
700 kJ/167 calories; 3 g protein; 0.6 g fat (includes 0 g saturated fat); 33 g carbohydrate; 6 g fibre

Cider, onion and gruyère toast
Everybody loves ‘melts’, especially when the weather is cold and wet! This one is basically a de-constructed French onion soup. You can also add extra chicken stock to the soft onion mix to make a soup and serve with toasted sourdough slices topped with a little melted gruyère. To reduce the fat and keep the flavour, use half the quantity of cheese (125 g) and grate it. It's a good one to make ahead for quick meals on chilly days. The best way to cut the onions finely is to use a mandolin. Keep any leftover cooked onion in the fridge.

Makes 8 pieces (depending on the size of the bread)


1 kg brown onions, peeled and sliced finely
1 bay leaf
sprig of thyme
1/2 cup (125 ml) dry cider
1/3 cup (80 ml) reduced fat chicken stock
8 slices (250 g) gruyère cheese
8 slices sourdough bread
  • Place the onions, bay and thyme in a large saucepan over a very low heat and sweat for an hour, with a tight lid, stirring occasionally. The onions must be completely soft with no bite in them, but do not allow them to burn.
  • Remove lid and herbs and increase heat. Add the cider and stock and stir until alcohol has evaporated and mixture has reduced with little liquid left.
  • Lightly toast sourdough bread, pile with onions and top with a slice of cheese (or sprinkle over grated cheese). Place under a pre-heated grill until the cheese is bubbling.
Per slice (250 g cheese)
1120 kJ/266 calories; 14 g protein; 11 g fat (includes 6 g saturated fat); 24 g carbohydrate; 3.5 g fibre

Per slice (125 g cheese)
849 kJ/202 calories; 10 g protein; 6 g fat (includes 3 g saturated fat); 24 g carbohydrate; 3.5 g fibre

Busting Food Myths with Nicole Senior

Myth: Some foods are aphrodisiacs.

Nicole Senior

Fact: If aphrodisiac foods are those which get you in the mood for love (improve your libido), then the hype surrounding foods such as oysters may be more folklore and fun rather than scientific fact. Human desire is rather more psychological than nutritional. It is probably the care and devotion involved in sourcing, preparing and sharing special foods, and the sensuality of eating them that set the scene for love, rather than the nutrients they contain. However, if the spirit is willing, the equipment must also be in order and this is where food can help.

Physical problems in the bedroom are far more common in men, and erectile dysfunction (ED) is the most common culprit. Unfortunately, it occurs far too often. In a study of more than 31 000 men in the US (The Health Professionals Follow Up Study), moderate to severe erectile dysfunction was reported by 12% of men younger than 59 years; 22% of men aged 60 to 69 years; and 30% of men older than 69 years. So what can be done to avoid this distressing problem?

The blood vessels ‘down south’ become blocked just as they do in the heart because of atherosclerosis. Erectile dysfunction is an early warning sign of high cholesterol and cardiovascular disease. It is also much more likely in men with the metabolic syndrome and diabetes. Young men take note: maintaining a healthy weight, lowering LDL (bad) blood cholesterol levels, maintaining ideal blood pressures and NOT smoking are important ways to look after your blood vessels and keep you loving for longer. And the same principles apply to reducing the problem once it occurs. Studies show that lifestyle changes such as lowering LDL (bad) cholesterol, losing weight, and exercising can enhance sexual function by up to 70%!

So, a heart-friendly diet and lifestyle can keep your heart beating strongly in more ways than one. So what’s on the menu when it comes to food for love?

  • Colour his world with plenty of different types of vegetables and fruits
  • Make him whole again with plenty of wholegrains like oats, wholewheat breads, pasta and breakfast cereals, barley and brown rice
  • Feed him like a Greek God with Mediterranean fare such as legumes, fish, fruit and nuts
  • Grease his wheels by replacing butter, cream, pastries and fast foods with healthy oils and trans-free margarine spreads based on sunflower, canola, soybean and olive oils.
  • Give him longer lasting energy with lower GI foods such as reduced-fat milk and yoghurt, grainy breads, pasta, legumes and fruits.
It’s official: men who ‘eat to beat cholesterol’ and exercise more have better sex. Oh, and gentlemen: surveys of women suggest if you help with the housework she’ll be more receptive to your amorous advances so don’t forget to help with the washing up!

Click on the cover to purchase

Dietitian Nicole Senior is author of Eat to Beat Cholesterol available online at: http://www.eattobeatcholesterol.com.au/

Dr David’s Tips for Raising Healthy Kids

We have the power to choose the shape of things to come
Here’s how Patty Nolan made a difference. Patty works at Warren Point Elementary School in Fair Lawn New Jersey. Noticing a rapid increase in the number of overweight kids, she launched a novel health and fitness program along with school nurse Kathy Szabo. Since the program began in 2003, it has been incorporated into the curriculum of every elementary school in the district and has won a state award. Here’s Patty’s inspirational story.


‘My main focus was to get the community moving. The plan we came up with had three different layers. First find activities most kids would like. Second get parents involved – kids are more likely to be active if they see their parents moving. Third put together a large event that involved the whole community. I started by getting the kids involved at lunchtime. Every lunch period, every day of the week, a different fitness activity takes place.

  • On Moving Mondays, I run laps around school grounds with the kids cheering them on. The math teachers encourage children to log their miles and add up their results.
  • Tournament Tuesdays have competitive games between teams; 85% of the students participate, and final winners earn awards at lunch.
  • On Walkin’ & Wheelin’ Wednesdays, kids and parents walk, rollerblade or bike to school. Once kids do this 15 times, they get on the health and fitness honor roll.
  • On thirsty Thursdays, everyone brings a water bottle to school and learns the benefits of staying hydrated.
  • On Fat-free Fridays, healthy eating is encouraged, and the school doesn’t sell ice-cream or unhealthy snacks during lunch.
Since the program started the kids have been really excited about competing in tournaments, running laps and promoting healthy eating. Just about every student in the school has participated. And with the parents signing permission slips, they’re aware of the revolution going on in the lunch hour. The first year we also held a fitness expo for the school community. Another event that has continued annually is the run/walk involving families through the community.

Year after year the response to the program has been overwhelmingly great. It’s rewarding to hear the comments from the kids who ask me if they can still run on Mondays even if it is raining. Parents tell me they are walking more, watching what they eat and losing weight. The kids are starting to eat better, to get more exercise, and to do it as a family.’

Dr David Ludwig

– Dr David Ludwig is Director of the Optimal Weight for Life (OWL) program at Children’s Hospital Boston and author of Ending the Food Fight

Move It & Lose It with Prof Trim

Exercise builds brain health
In a recent review that would take slightly more space to do it justice than the paragraph devoted to it here, University of California-Irvine brain researchers have concluded that exercise is not just good for the body, but can also be good for the brain. It does this by allowing the production of growth factors which allow for neurogenesis in the part of the brain (hippocampus) associated with learning and feelings of well-being.

Dr Garry Egger aka Prof Trim

Growth factors are molecules that promote the health of specific cells; they are produced by cells other than the ones they nourish. Nerve growth factors (neurotrophins) play vital roles in nourishing and supporting nerve cells. A growth factor called BDNF (for brain-derived neurotrophic factor) increases significantly in the brains of animals that run voluntarily. Researchers have found that laboratory animals that voluntarily run on an exercise wheel show increases in the generation and survival of new neurons (brain cells) in the hippocampus This increased neurogenesis is associated with improved learning. ‘You're literally building the structure of the brain, just by moving your feet.’ says lead writer Carl W. Cotman, PhD.

Not only does regular exercise promote neurogenesis, it also:

  • Improves concentration and attention
  • Reduces loss of gray matter
  • Strengthens synapses (in animals, running also increases the strength of synaptic connections), and
  • Enhances blood flow
Trends in Neurosciences (2007) Exercise builds brain health: key roles of growth factor cascades and inflammation Trends in Neurosciences 30 (2007) 9, 464–472

– Click for more information on Professor Trim.

Your Questions Answered

What’s the difference between GI, GL and ‘low glycemic’? Which should I use and does it really matter?
We are often asked this question. Hermin Halim who recently graduated MNutriDiet from the University of Sydney sorts out the confusion.

Hermin Halim

Many people’s lives have been better off with the low GI diet as the success stories published in GI News show month after month where we see people achieving weight loss, better blood sugar control, better overall health, better stamina, and so on. What makes GI stand out is that no real counting is needed (such as calorie counting) – by choosing a low GI food rather than a higher GI food, you see a lower and steadier rise in blood glucose while eating the same amount of food. Looks straightforward, but still, quite a few people find it confusing.

So what is GI all about? Principally, GI is based on the quality (the characteristics) of carbohydrate in food; that is, how quickly or slowly the blood glucose will rise with the consumption of this food. It is worked out from the increase in blood glucose after eating 50 g carbohydrate portion of the food, compared with 50 g pure glucose – the form of sugar that is present in our blood.

Yet some people are still quite resistant to GI – they say that they find it confusing and complicated, and point to ‘healthy’ foods with a high GI like watermelon. Well yes, watermelon does have a high GI, but this shouldn’t discourage anyone from eating it, because a typical serving size (a 120 g/4 oz wedge) only contains 6 g available carbohydrate so will have very little impact on your blood glucose levels. In fact, to get 50 g carbohydrate from watermelon, you would need to eat 1 kg watermelon – and that’s a lot!.


And this is where what’s called GL (glycemic load) come into the picture because it takes into account both the GI (carbohydrate quality) and the amount of carbohydrate in the portion size. Sounds more practical than GI, doesn’t it? But it’s not that easy. This is because there are two routes to a low GL – a food can either have a low GI or be low in carbs (like watermelon). So although watermelon has a high GI, its GL or glycemic impact is low because it has so little carbohydrate. So it won’t spike those blood glucose levels.

So why bother about GI if eventually you have to calculate both the total carbohydrate content and the GL? This is where one of the strongest objections to GI (and the best support for GL) came from. The proponents of GL even back it up with some ‘compelling’ evidence on the benefits of low GL diet in weight loss, heart disease, diabetes, obesity, and certain cancers. And interestingly, the food doesn’t have to be low GI. Low carbohydrate, high protein diet was also effective in all these, even diabetes, so why should we have more carbohydrate? After all, people tend to prefer meat, chicken, cheese, and egg more than the tasteless grains and cereals. This adds fuel to the already heated controversy. So how do GI experts react to this?

Prof Jennie Brand-Miller makes the point that while there are lots of ways to lower the GL, ‘at present it is not clear that all will be equally beneficial.’ It is true that one could lower the GL by lowering the carbohydrate content, but is it achievable? Professor Brand-Miller points out two main flaws of low-carb diet. Firstly, that it may not be healthy because of its high saturated fat content – and this fat increases the risk of heart disease, so probably would cancel out the reported benefits of low carbohydrate diet anyway. Secondly it is not feasible as this involves limiting even moderate sources of carbohydrate (such as fruit and dairy products) which contain lots of important nutrients.

A low GI diet, on the other hand, is healthy and is in line with the Guide for Healthy Eating in Australia (and the Healthy Eating Pyramid elsewhere) which suggests that our everyday eating should be based on grains – high carbohydrate, low fat, nutritious foods – and with them, fruit, vegetables, low-fat dairy, and protein foods that are low in saturated fats (including nuts and legumes). With the low GI diet, you’ll be eating the five food groups in the balanced amount without missing out on nutrients. You’ll also find it easier to follow, as it’s close to your usual eating pattern. For a diet to be easy to be effective in the first place, it has to be easy to stick to. That’s why Professor Brand-Miller concludes, ‘the GI appears to be more effective’.


Your Success Stories

‘This is such the right way to go! I am a completely different person now.’ – Adriana
I have tried everything in the past – you mention it and I have done it from high protein regimens to eating pineapple + tuna every day or simply starving. I did not understand what was happening in my body and what was making me eat so much of the wrong types of food. The low glycemic concept came to me around two years ago and my life changed since. I forgot what is like to be in the yo-yo cycle, what is like to crave for food, being moody or having regular headaches when I am hungry. I now have excellent control of what I eat and I am a healthy weight. There are two reasons for this: I am not longer addicted to the high GI carbohydrates and I do not have to rely on my will to make this one work. This is the best way to start a healthy life style, achieve a healthy weight, keep it forever and prevent many chronic diseases proven to be related to overweight and obesity. Eating mostly low GI and doing regular exercise was the way to go for me. Give yourself a chance to experience this amazing way of living!


‘I love it and can see myself eating this way for years to come.’ – Jade
I was a 16-year-old rather heavy athlete. I couldn’t get the right times and I was a rather unhealthy eater. One day my parents brought home a recipe book from a diabetic friend who was on the low GI diet and had accidentally ordered two copies. They paid no real attention to it using it less frequently than other books that we had. One day I was looking in the cupboard where it was kept and read the first few pages about losing weight the healthy way (not too fast) and the benefits of eating low GI with sport. I read everything I could and then got a copy of the other book that explained the whole concept. And that was the start of a new me. I stuck to it from day one and I have amazing results from it. I leaned up, lost a lot of excess weight and did really well in my cross-country season this year (2007) just from losing the extra weight. My parents don’t try to eat lower GI as I do, but they do help me in buying me whatever I need and have said repeatedly how proud they are of me, sticking to something and putting my whole heart into it. And not quitting. At times I didn’t eat what they would eat or I would take food from home instead of eating the higher GI foods that would be served at parties and functions. I run or work out and look forward to having my favourite snack that is higher GI, and it motivates me even more to work harder. And I love it and can see myself eating this way for years to come. I am 18 now and try to get all my friends to stop being as ignorant as I was about their food choices because they are such easy choices to change.

success story

GI Symbol News with Alan Barclay

First formulated meal replacement product for the GI Symbol Program

The recent Cochrane review of six randomised controlled trials comparing low GI and low GL diets with other diets for overweight and obesity (reported in August 2007 GI News) determined that low GI diets were more effective at reducing total body weight and perhaps more importantly body fat, compared with conventional energy (Calorie/kilojoule) restricted diets over a 6-month period.

USANA Nutrimeal® balanced nutritional drink mixes combine the benefits of both energy restriction and low GI (23) to facilitate optimal weight loss when consumed as directed as a snack or meal replacement. High in fibre (8 g per serve), USANA Nutrimeal is the first formulated meal replacement product to join the GI Symbol Program. For more information see this page.

Alan Barclay

Alan Barclay, CEO, Glycemic Index Ltd
Phone: +61 2 9785 1037
Fax: +61 2 9785 1037
Email: awbarclay@optusnet.com.au
Web http://www.gisymbol.com.au/

The Latest GI Values

Where can I get more information on GI testing?
North America
Dr Alexandra Jenkins
Glycemic Index Laboratories
36 Lombard Street, Suite 100
Toronto, Ontario M5C 2X3 Canada
Phone +1 416 861 0506
Email info@gilabs.com
Web http://www.gilabs.com/

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 http://www.glycemicindex.com/

New Zealand
Dr Tracy Perry
The Glycemic Research Group, Dept of Human Nutrition
University of Otago
PO Box 56 Dunedin New Zealand
Phone +64 3 479 7508
Email tracy.perry@stonebow.otago.ac.nz
Web glycemicindex.otago.ac.nz

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