2 April 2006

GI News—April 2006

collage

In This Issue:

  • Food for Thought
    —Potato Lovers Look Back to a Healthy Future
  • GI News Briefs
    —Memorable Meals
    —Men are Different
    —A Heart-healthy Diet
    —Devaluing the Value of GI
  • GI Values Updates
    —How do you know if it’s low, medium or high GI?
  • Low GI Food of the Month
    —Wild About Blueberries
  • Low GI Recipe of the Month
    —Lemon Semolina Pudding with Berry Coulis
  • Success Stories
    —Jeanne: ‘I lost over 100 pounds using a combination of good eating habits and low GI foods.’
    —Anne’s Story: Battling hypoglycemia
  • Books, DVDs, Websites: What’s New?
    —The Spanish language edition of The New Glucose Revolution
    —The Korean language edition of The New Glucose Revolution
    —Translate GI News and www.glycemicindex.com to another language
  • Feedback—Your FAQs Answered
    —How relevant is the GI for athletes in terms of carbohydrate metabolism?
    —I have recently been diagnosed with celiac disease (gluten sensitivity) on top of diabetes. It's extremely hard to find both low GI and wheat-free foods. Any suggestions?
    —I am a type 1 diabetic and enjoy an occasional beer or dry wine. What’s the real deal on the GI of alcoholic beverages?
quote

If you have posted a question in our newsletter, be assured that the GI Group will answer this as soon as possible. We welcome your views about our articles and other reader’s suggestions. Please POST your comments on the site.

If you want to send a story in GI news to a colleague or friend, simply click on the MAIL ICON mail next to 'Comments' at the end of the story you wish to share.

To receive our free e-newsletter each month, click the SUBSCRIBE link in the right-hand column. Your email address will be kept strictly confidential and you can unsubscribe at any time.

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

Food for Thought

Potato Lovers Look Back to a Healthy Future
There’s a ‘modest positive association between the consumption of potatoes and the risk of type 2 diabetes in women’ write the authors in a prospective study reported in the February 2006 issue of the American Journal of Clinical Nutrition. ‘This association was more pronounced when potatoes were substituted for whole grains.’ The Harvard investigators conducted a prospective study of 84,555 women, aged 34 to 59 years with no history of chronic disease, who were enrolled in the Nurses' Health Study. The women completed a validated food frequency questionnaire and they were followed up for 20 years with repeated dietary assessments. During the study, 4,496 participants were diagnosed as having type 2 diabetes. After adjustment for age and dietary and non-dietary factors the researchers found that those with the highest potato intake (around one serving a day) had a modestly elevated risk of developing type 2 diabetes (about 20% higher). The link was strongest among obese women, who are already at increased risk of the disease, suggesting that heavy potato consumption may pose a particular problem for them, the researchers point out. ‘These data support a potential benefit from limiting the consumption of these foods in reducing the risk of type 2 diabetes,’ conclude the authors. ‘Substitution of these sources of carbohydrate with lower glycemic, high-fibre forms of carbohydrates such as whole grains should be encouraged.’

potatoes

Cutting back on potatoes is something many people on a low GI diet find hard to do. So what’s the answer?
First of all, there’s no need to say ‘no’ to potatoes altogether just because they may have a high GI. They are fat free (when you don’t fry them), nutrient rich and filling. Not every food you eat has to have a low GI. So enjoy them but in moderation.

Secondly, look for the lower GI varieties of potato or serve them in a way that reduces the glycemic response. University of Toronto researchers found that the GI of potatoes ranged from 56 to 89 depending on variety and cooking method (Journal of the American Dietetic Association). Precooking and reheating potatoes or consuming cold cooked potatoes (such as potato salad) reduced the glycemic response. The highest GI values were found in potatoes that were freshly cooked and in instant mashed potatoes. Margareta Leeman and her colleagues at the University of Lund in Sweden found that preparing potatoes the day before and serving them cold as potato salad with a vinegary vinaigrette dressing can lower the GI (European Journal of Clinical Nutrition). In Low GI Eating Made Easy, dietitian Kaye Foster-Powell suggests steaming small new potatoes (with their skin for added nutrients), or bake a jacket potato and add a tasty topping based on low GI beans, chickpeas or corn kernels.

Third, remember that potatoes are a relative newcomer to the Western dinner plate. Athough the Spanish brought them back to Europe from South America in the mid-sixteenth century, people tended to regard them with suspicion and fit only for animals. They didn’t become a regular part of the European diet until the late eighteenth century. And it wasn’t until the nineteenth century that we really developed a taste for them replacing traditional wholegrain staples such as wheat, barley, rye and oats, which have much lower GI. So look back to a healthy future and add variety to your meals by enjoying wholegrains, legumes, pasta, noodles, basmati rice on a regular basis and potatoes occasionally. You’ll reduce the overall GI and GL of your diet and your risk of chronic disease.

GI News Briefs

Memorable Meals
In recent years, a number of studies have shown that older people with type 2 diabetes have significantly greater risk of performing poorly in cognitive function tests such as recalling word lists. University of Toronto researchers say that a low-GI meal generally results in better verbal memory in the post-meal period, particularly in those who experience the greatest food-induced elevations in blood glucose levels, compared with a high-GI meal.

pasta

They reported their findings of a study involving 21 older adults (10 males, 11 females) with type 2 diabetes in the March 2006 issue of Diabetologia. Both the GI of the carbohydrate meal and individual differences in response to the meal contributed to the variation in consequent memory recall, they write. The scientists had set up the study to determine whether minimising the increase in blood glucose by eating a low GI meal (50 g pasta) rather than a high GI meal (50 g bread) would affect cognitive performance in the post-meal period. They found that:

  • Bread consumption, relative to pasta, resulted in both a higher area under the curve and worse delayed verbal memory (paragraph and word list recall) performance;
  • Performance following bread consumption was poorer than that following pasta on measures of working memory, executive function and auditory selective attention;
  • Sustained attention showed no sensitivity to type of carbohydrate food consumed.
Diabetologia, March 2006 (email: carol.greenwood@utoronto.ca)

Men Are Different
Men with cardiovascular disease may be at considerably increased risk for death even when their blood sugar level remains in the ‘normal’ range, suggests a new study by a team of scientists at UCLA and Cedars-Sinai Medical Centre in Los Angeles published in the American Journal of Epidemiology. Using extensive data from the Framingham study collected between 1948 and 1978, the scientists statistically analysed the connection between glucose (blood sugar) levels and death in patients with cardiovascular disease. ‘While our results show that glucose is a strong independent predictor of mortality,’ writes lead author Dr Sidney Port, ‘they also unequivocally show that the mortality/glucose relations are quantitatively different for men and women. Indeed for men risk rises very rapidly through the normal range and is flat thereafter. For women, risk is unrelated to glucose in the normal range, then rises quickly through the impaired range and at a much slower rate thereafter.’ The findings suggest that: ‘although 5.55 mmol/liter (= 100 mg/liter, normal) may be a useful mortality risk division (albeit with different implications for men and women), 6.99 mmol/litre (= 126 mg/litre, diabetic) is not, especially for men.
American Journal of Epidemiology, vol 163, No. 4

A Heart-healthy Diet
Foods based on soybeans have a beneficial role in our defence against heart disease.

heart
photo: New England Journal of Medicine

There are three attributes of soybeans with the potential to reduce heart disease risk:
  1. soy protein
  2. anti-oxidant substances called isoflavones
  3. low GI carbohydrate
In a new study published in Nutrition, lead author Dan Lukaczer reports that postmenopausal women on a low GI diet (incorporating 30 grams of soy protein and 4 grams of phytosterols a day) showed a ‘significantly greater improvement’ in CVD risk factors compared with women on the AHA Step 1 diet. Scientists from the Functional Medicine Research Center of Mutagenics Inc., the company that manufactures the fortified soy beverage used in the study, carried out the 12-week study. The average age of the women in the study was 55, and all were clinically obese and at higher risk of CVD. Both groups started with high levels of total cholesterol, low-density lipoprotein (bad) cholesterol and triacylglycerols. The scientists collected 3-day diet records from the women at weeks 2, 4, 8 and 12. At the end of the program the low GI group showed statistically significant decreases in total cholesterol, low-density lipoprotein cholesterol and triglycerols say the authors. In addition, high-density lipoprotein (good) cholesterol rose significantly in the low GI group group, but not the AHA Step 1 diet group.
Nutrition (Vol 22, pp104–113)

Evaluating the value of GI …

‘The present results call into question the utility of GI and GL to reflect glycemic response to food adequately, when used in the context of usual diet’ write Elizabeth Mayer-Davis and her co-authors reporting their study in the British Journal of Nutrition. Using the glucose tolerance and insulin sensitivity data for 813 adults who participated in the Insulin Resistance Atherosclerosis Study, the researchers set out to evaluate the correlation of GI and GL with measures of glycaemia based on the responses the participants had given to that study’s food frequency questionnaire. They assigned mean GI values based on published data. Despite acknowledging the limitations of their study, their major finding was that ‘no statistically significant association was observed for GI in relation to fasting glucose, postprandial glucose, incremental postprandial glucose or A1c either at baseline [the start date] or at the follow-up examination.’
British Journal of Nutrition (2006), 95, 397-405

GI Group: This study has attracted an amazing amount of headline-making media mileage and we have received a number of inquiries from GI News readers. Here is a brief summary of our key concerns with the design of this study and its findings.
  1. The food frequency questionnaire used for Insulin Resistance Atherosclerosis Study has a poor correlation (just 0.37) with other measures of carbohydrate intake. What this simply means is that it doesn’t provide truly reliable data on how much carbohydrate the volunteers ate. Without accurate information on an individual’s carb intake it is unlikely they can confidently assess its GI or to calculate GL. Assessing food intake from food frequency questionnaires (FFQ) is subject to error and bias (it’s human nature for people to under-report some foods and overestimate others). This is why researchers always compare the estimates of nutrient intake from FFQs with an independent method such as a dietary record. A good study will have a correlation value above 0.5.

  2. No FFQ has been validated as truly reflecting the GI of a diet. For example, one question reads: ‘How often do you eat dark bread (including whole wheat, rye, pumpernickel, other high-fiber bread)’. Obviously the GI values of these various breads can vary greatly, yet a single GI value was assigned to all responses to this question.

  3. The cross-sectional, rather than prospective, nature of the Insulin Resistance Atherosclerosis Study. A better study would take either normal individuals or people with impaired glucose tolerance (IGT) and track changes in glucose metabolism over time and try to relate those changes to differences in food quality (such as the Harvard Nurses' Studies).

GI Values Update

How do you know if it’s low, medium or high GI?
Living in the USA, where would you suggest I look for GI information on our food? Or are foodstuffs pretty comparable? Any US sites you would recommend?’

veggies

Low GI eating often means making a move back to staple foods – fruit, vegetables, legumes (home-cooked or canned beans, chickpeas and lentils), wholegrains (pearl barley, bulghur), pasta, noodles, dairy foods (milk, yoghurt) – which naturally have a low GI, so it doesn’t matter which brand you buy. The top 100 low GI foods are listed in Low GI Eating Made Easy (US edition: Marlowe & Company) along with ideas for including them in your meals. When it comes to carb-rich processed foods such as breakfast cereals, bread, bakery items (cookies, cakes, muffins etc), you do need to know the GI of different brands as it can range from low to high and there’s no easy way to make an educated guess. To find the GI of your favourite brands you can:

  • Look for an independently accredited GI symbol on the product
  • Check the nutritional label – some manufacturers now include GI (but you need to be sure that an accredited lab tested the food. (See our note below on when to be wary.)
  • Visit www.glycemicindex.com to search the database
  • Contact the manufacturer and ask (hound) them to have the food tested by an accredited lab.
GI testing – make sure an accredited lab tested the product
Not all claims are reliable. Why? Well, The GI rating of a food must be tested physiologically and only a few centres around the world currently provide such a testing service (see our list below). In fact the GI is defined by its internationally standardised method of testing in human subjects (we call this in vivo testing). You may hear about in vitro (test tube) methods, but these are simple short cuts, which may be useful for food manufacturers developing new products, but may not reflect the true GI of a food. Here’s a list of the accredited labs we know (in no particular order) that carry out GI testing following the internationally standardised method. Apologies to any we have left out – please send us your details so we can publish them in future editions of GI News.
Symbols to look for
When you see one of these symbols you will know that the food has been tested by an accredited lab.

The GI Symbol Program
This international symbol is a guarantee that the product meets strict nutritional criteria. Glycemic Index Limited is a non-profit company established to run the GI Symbol Program. Its members are: the University of Sydney, Diabetes Australia and the Juvenile Diabetes Research Foundation. For more information, visit www.gisymbol.com.

gi logo
International GI Symbol

Sainsbury's and Tesco
In the UK, Sainsburys and Tesco are testing and labelling foods low and medium Gi across a range of products.

sainsbury
Sainsbury's

tesco
Tesco

When you need to be wary
Sometimes a GI value may be too low to be true. If a manufacturer is promoting a carb-rich processed food with an ultra low GI, be wary before you buy. Processed foods such as breakfast cereals and breads and bakery products are very unlikely to have a very low GI. In fact, if the GI is less than say 50, we suggest that you ask the manufacturer for the name of the lab that tested it and the method that was used.

Low GI Food of the Month

Wild About Wild Blueberries
Make blueberries an everyday health habit. As one of today’s superfoods, they are bursting with nutrition and flavour while being very low in kilojoules/calories. They are popular for eating fresh or using in pancakes and smoothies, muffins, jams, as a snack and in many other dishes and desserts.

blueberries

But like us, you probably didn’t know that not all blueberries are the same. Most blueberries you buy in the supermarket or fresh produce store will be cultivated highbush blueberries (Vaccinium corymbosum L). In the US, it’s also possible to buy frozen wild blueberries (V. angustifolium), all year long (GI 53 tested by Glycemic Index Laboratories, Inc). Wild blueberries are smaller, about one-third the size of cultivated and have a more intense blueberry flavor and they retain their shape well in cooking. Wild blueberries are also significantly higher in anti-oxidant activity than their cultivated cousins. In fact, they are richer in anti-oxidants compared with more than 20 other fruits (Journal of Agricultural and Food Chemistry, 2004, 52: 4026-4037) including cranberries, strawberries, plums, and raspberries. The blue pigment in blueberries called anthocyanins is responsible for most of the antioxidant activity. Blue is good for you!

Wild blueberries are one of three berries native to North America – the others are cranberry and Concord grapes. They thrive in the northern climate of Maine, Atlantic Canada and Quebec where the growers manage the traditional fields and ‘barrens’ to encourage the crop to grow in a sustainable fashion. Although they are may be harvested in a traditional way (with hand-held berry rakes), they are sorted, cleaned and processed using state-of-the-art-technology to preserve their flavor, quality and anti-oxidant qualities. Frozen wild blueberries are shipped world wide Japan, Europe, Korea, Middle East, and Australia. Fresh wild blueberries are only available during the short season locally in Maine and Canada. (Wild blueberries have never been hybridized so don’t ship well in the fresh state or hold up in stores for any length of time.)

Try these quick and easy serving suggestions for fresh and frozen wild blueberries:

  • Combine blueberries with a little caster sugar and a tablespoon or two of balsamic vinegar or a little white wine or orange juice. Let the flavours develop for 30 minutes or so at room temperature then serve on their own or with low-fat ice-cream
  • Make blueberry smoothies with low fat milk, soy milk or yoghurt for breakfast or a meal in a glass when you are on the run.) If you use frozen fruit you don’t need ice cubes.
  • Add 1/2 cup to your morning cereal or yoghurt or yogurt
  • Toss them into pancake or waffle batter
  • Sprinkle them into your garden salad or fruit salad
For a selection of tasty wild blueberry recipes go to www.wildblueberries.com

Low GI Recipe of the Month

Lemon Semolina Pudding with Berry Coulis
Lisa Lintner’s Lemon Semolina Pudding with Berry Coulis from The New Glucose Revolution Life Plan.

dessert
Photo: Jennifer Soo

Serves 6

2 cups (500 ml/17 fl oz) low fat (semi skimmed/1%) milk
½ cup (100 g/3½ oz) fine semolina
¼ cup (60 g/2¼ oz) sugar
1 teaspoon vanilla extract
1 large lemon (zest only)
1 egg, lightly beaten
300 g (10½ oz) blackberries, strawberries, or raspberries or a mixture
2 tablespoons icing (confectioner’s) sugar
½ cup (125 ml/4 fl oz) white wine or apple juice

  1. Preheat the oven to 350°C. Lightly oil six ½-cup (125 ml/4 fl oz) soufflĂ© dishes. Line the base of each dish with baking paper.
  2. Pour the milk, semolina and sugar in a saucepan and bring to a boil, stirring constantly. Reduce the heat and stir for 1 more minute.
  3. Remove from the heat and stir in the vanilla extract and lemon zest.
  4. Cover the surface of the mixture with plastic wrap to prevent a skin forming, and cool. When cooled, stir in the beaten egg.
  5. Spoon the mixture into the prepared dishes and place them into a baking pan with enough boiling water to reach halfway up the sides of the dishes. Cover loosely with a large sheet of foil. Carefully slide the pan into the oven and poach the puddings for 15 minutes, until set. Remove the puddings from the pan of water. Run a knife around the puddings, turn out onto serving plates and remove the piece of baking paper.
  6. Meanwhile, puree most of the berries with the icing (confectioner’s) sugar. (Reserve some whole berries for decoration if desired). Thin the coulis with white wine or apple juice.
  7. Pour the coulis around the puddings, and decorate with slivers of lemon peel or whole berries (optional).
Nutritional analysis per serving
814 kJ (195 Cal), 3 g fat, 8 g protein, 35 g carbohydrate, 2 g fibre, low GI

Your Success Stories

Jeanne’s story – ‘I lost over 100 pounds using a combination of good eating habits and low GI foods’
After the birth of my eighth child instead of losing weight I started to gain. We were gaining nicely her and I. The problem was she was supposed to and I was suppose to snap back – isn't that the way it works? A few years earlier, I had started to snore, had reflux and I had a constant ache in my right side, which was gall bladder. I knew in my heart it was diet related as most illnesses are, but I did nothing about it.

When my daughter was about a year old I had had it. Weighing in over 270 pounds I decided to change the way I ate. I found that certain foods made me feel better and lose weight. I made the change. I don't call it a diet because I feel diets fail and I am not failing. I eat low glycemic carbs. But I eat lots of carbs. There you are, with the right foods you can eat what you want and feel satisfied and lose the weight. It speaks for itself. I also eat protein to build muscle mass and low fat dairy. I am now in good shape I feel I have a ton of energy. I am rid of reflux, no more pain in right side and best of all no fatigue. ‘I have lost over 100 pounds using a combination of good eating habits and low GI foods. It is not a diet because it doesn't fail. My skin tone is great and my general health has improved. I forgot to mention I am a person that will not eat white sugar. Sucrose, frutose, any ose is not for me.

Anne’s story – battling hypoglycemia
My life has always been controlled by my hypo attacks. I never go anywhere without a ‘fix’ in my pocket, be that an apple, a packet of chocolate nuts and raisins or a carton of juice. My story starts when I was an early teenager in 1957. I would be miles from home, roaming the countryside when I would gradually develop an inability to function properly, which manifested itself in weakness, perspiration and irritability. I was fortunate if an attack took place during autumn as I could find blackberries, crab apples or sloes to eat until the feeling passed. Instead of walking home I would have to sit and wait for a bus. I began to notice a pattern to these attacks. They nearly always took place in late afternoon. I had a long way to travel to and from my school involving a long walk, a ferry trip and a train journey. At the end of the school day I couldn’t wait to get home to have something to eat. My school life was totally disrupted by these attacks and I could never stay on at school and enjoy extra curricular activities or extra study. Concentration levels were poor and my school work suffered.

I was better able to control my eating patterns once I started working. When I became a working mother, however, with two children, shopping after work, etc. I found that once again my cravings during the late afternoon were almost unbearable. I resorted to sherry as soon as I reached home and this sustained me whilst I cooked a meal and attended to the usual chores. I found that alcohol, together with assorted savoury nibbles was the answer to giving me that vital boost when I was flagging. As far as I was concerned, I was just an oddity – no one I knew could sympathise or understand my problem and probably thought I was just greedy. I never seem to reach the stage of feeling full and can just go on eating and eating. I don’t. I stop when I realise that I should have eaten a sufficient amount but I don’t feel full. I think part of the problem is that I still tend to eat a ‘traditional’ meal of carbohydrates, protein and vegetables. When I am hungry I cannot face a salad, however varied and interesting. I have found that eating a small snack every two hours or so does stop me from reaching the stage where I lose the ability to be sensible. I should add that I do not have a sweet tooth and have always eaten sensibly, except when I am experiencing a sugar ‘attack’ and then I will eat anything to hand. I have brought up the subject with various GPs over the years.

I have discovered over the years that the foods I like most are my worst enemies. These include potatoes, bread, bananas, rice and alcohol. In the last month I have stopped drinking alcohol and limited my intake of potatoes and bread. I try to eat oat bread wherever possible and am following the low glycemic principle as far as possible. I know when I have eaten the wrong thing and, instead of turning to alcohol I eat a yoghurt or some apricots until I feel comfortable again.

Send Us Your Success Story!
success story

Books, DVDs, Websites: What’s New?

Los Todos Los Carbohidratos Engordan
The Spanish language edition of The New Glucose Revolution is published by Panorama Editorial. www.panoramaed.com.mx

spanish book

The New Glucose Revolution
The Korean language edition of The New Glucose Revolution is published by Aquarius Publishing Co.

korean book

For information on other translated editions visit www.glycemicindex.com then select ‘GI Books’ and the appropriate region

Translating GI News and www.glycemicindex.com
If you would prefer to read GI News or a page from glycemicindex.com in a language other than English, there is a very easy way to translate them (or any site for that matter), using a service provided by Altavista called ‘Babel Fish’. Simply head over to www.babelfish.altavista.com and copy and paste a block of text into the first window (up to 150 words), or enter the website address to translate an entire page into the ‘Translate a Web Page’ box. Next, select which language you would like the English text translated to from the drop-down menu. Click the Translate button and Babel Fish will do all the work for you in just a few seconds.

babel fish
Babel Fish homepage

www.glycemicindex.com

Glycemicindex.com, the official website of the glycemic index, just passed the 3-year mark with access to statistics via Extreme Tracking. In all, nearly 3 million hits – about 950,000 individual hits per year. Who visits? Countries providing the most visitors are: USA 44%, Australia 13%, UK 10% and Canada 6%. The site was set up by the University of Sydney to make the GI database of foods tested worldwide according to the standardised in vivo procedure accessible to everyone who needs this information free of charge. There’s no need to subscribe. It provides up-to-date information on the glycemic index and the published GI values of foods tested internationally according to the established procedure along with details about GI testing, the GI symbol program, the most common FAQs and a selection of books on GI published internationally. The site is interactive and the GI Group answers queries.

gicom
Glycemic Index homepage

Feedback—Your FAQs Answered

How relevant is the GI for athletes?
'The glycemic index can be a useful tool to help athletes select the right type of carbohydrates to consume both before and after exercise,’ says Dr Emma Stevenson. ‘Several studies have investigated the effect of changing the GI of carbohydrates eaten before exercise on substrate metabolism during prolonged endurance exercise. Studies have consistently reported that a low GI pre-exercise meal results in a better maintenance of blood glucose concentrations during exercise and a higher rate of fat oxidation. This is likely to result in reduced muscle glycogen utilization during prolonged exercise and possibly improve endurance performance. Eating high GI meals before exercise may result in plasma glucose concentrations peaking before the onset of exercise and then hypoglycemia occurring within the first 30 minutes of the exercise period. There is little data available on the effect of the GI of carbohydrates eaten before intermittent, power or strength related sports.'

'During recovery from exercise, muscle glycogen resynthesis is of high metabolic priority. The eating high GI carbohydrates after exercise increases plasma glucose and insulin concentrations and this facilitates muscle glycogen resynthesis. If however, you are exercising for weight loss purposes or are involved in weight restricted sports, low GI carbohydrates after exercise may be more beneficial as the lower glucose and insulin concentrations will not suppress fat.'

athletes


‘I have recently been diagnosed with celiac disease on top of diabetes. Any suggestions for foods that are both low GI and wheat-free foods?’
This is not as hard as you may think. If you like Asian food – Indian dahls, stir-fries with rice, sushi, noodles - you're in luck, because they are all low GI. Choose vermicelli noodles prepared from rice or mung beans and low GI rices such as basmati. Use sweet potato instead of potato, use all manner of vegetables without any regard for their GI. Choose fruits and dairy for their low GI. If you can tolerate dairy products, then take advantage of them for their universal low GI. If lactose intolerance is a problem, reach for live cultured yoghurts and lactose-hydrolysed milks. Even ice-cream can be enjoyed if you ingest a few drops of lactase enzyme first. Dietitian Kate Marsh, however says: 'people need to check the labels of yoghurts and ice-cream for gluten as many do contain wheat based thickeners.'

What’s the real deal on the GI of beer?
Beer has so little carbohydrate that it's difficult to test its GI. That's why we listed its GI and GL as 0 in earlier editions of the New Glucose Revolution series books. But eventually we decided that the valid way to test beer would be by comparing responses to a 10 g carbohydrate portion of beer (about 300 mL) with a 10 g carbohydrate portion of glucose (in GI testing a 50 g carbohydrate portion is normally used). In this test the GI came out as 66. The GL will be therefore be 66 x 10/100 = 6.6 (round up to 7).

beer


‘I have diabetes, but I enjoy an occasional drink. Does the way a beer is brewed (ales, lagers, pilseners, stout etc.) have a significant impact on the final product and its sugar content?’

Generally, alcoholic beverages contain very little carbohydrate. Most wines and spirits contain virtually none; regular beer contains around 10 g carbohydrate per 12 fl oz can; stout around 14 g carbohydrate per 12 fl oz can while a light beer has from 3–7 grams of carbohydrate per serving (12 fl oz can). Compare this with 36 g carbohydrate in a can of regular (not diet) soft drink! So yes, a beer will raise your glucose levels but not excessively. And if you drink beer in large volumes (not a good idea really) then you could expect it to have a significant effect on blood glucose. Although we haven’t GI tested many brands of beer, there are some useful websites out there that will tell you how much carbohydrate there is in various brands. We use www.calorieking.com as a quick reference.

As for enjoying an occasional drink, researchers (Kaniz Fatima and Chris Middlemass) from the University of Sydney reported at the Nutrition Society of Australia (November 2005) that a pre-dinner drink tends to produce a ‘priming’ effect, flicking the switch from internal to external sources of fuel and keeping blood-sugar levels low. In one study, they gave healthy, young, lean people two standard glasses of beer, or wine, or gin and tonic or water to drink about an hour before eating a meal then they measured their blood glucose and insulin levels. They found that: ‘realistic amounts of beer, wine or gin reduce postprandial glycemia but not insulinemia’.

Printing Information
print info


© ® & ™ The University of Sydney, Australia