1 February 2009

News Briefs

Senior moments? It may be your blood glucose.
Senior moments are a normal, albeit unwelcome, part of aging, rather like wrinkling skin and graying hair. Scientists call them ‘cognitive aging,’ the result of changes in brain chemistry and physiology that affect our brain’s ability to think. Researchers at Columbia University Medical Center in New York suggest in Annals of Neurology, that controlling blood glucose may be a key factor in slowing down the normal changes as we age and preserving our cognitive health.


None of the 240 participants (average age 80) in the Columbia University study had symptoms of dementia or Alzheimer's. Mapping their brain regions using high-resolution functional magnetic resonance imaging, the researchers found a correlation between elevated blood glucose levels and reduced cerebral blood volume, or blood flow, in the dentate gyrus, an indication of reduced metabolic activity and function in that region of the brain.

‘Our findings suggest that maintaining blood glucose levels, even in the absence of diabetes, could help maintain aspects of cognitive health. More specifically, our findings predict that any intervention that causes a decrease in blood glucose should increase dentate gyrus function and would therefore be cognitively beneficial,’ said Dr. Small. ‘Whether with physical exercise, diet or through the development of potential pharmacological interventions, our research suggests that improving glucose metabolism could be a clinically viable approach for improving the cognitive slide that occurs in many of us as we age,’ concluded Dr. Small.

Scott Small MD

Fruit and vegetables may strengthen your bones
Diets that are high in protein and cereal grains produce an excess of acid in the body which may increase calcium excretion and weaken bones, according to a new study published in the Journal of Clinical Endocrinology & Metabolism. The study found that increasing the alkali content of the diet, with a pill or through a diet rich in fruits and vegetables has the opposite effect and strengthens bone health.

‘Heredity, diet, and other lifestyle factors contribute to the problem of bone loss and fractures,’ said lead author Dr Bess Dawson-Hughes of Tufts University. ‘When it comes to dietary concerns regarding bone health, calcium and vitamin D have received the most attention, but there is increasing evidence that the acid/base balance of the diet is also important.’

Average older adults consume diets that, when metabolised, add acid to the body. With aging, we become less able to excrete the acid. One way the body may counteract the acid from our diets is through bone resorption, a process by which bones are broken down to release minerals such as calcium, phosphates, and alkaline (basic) salts into the blood. Unfortunately, increased bone resorption leads to declines in bone mass and increases in fracture risk.

‘When fruits and vegetables are metabolised they add bicarbonate, an alkaline compound, to the body,’ said Dr. Dawson Hughes. ‘Our study found that bicarbonate had a favourable effect on bone resorption and calcium excretion. This suggests that increasing the alkali content of the diet may attenuate bone loss in healthy older adults.’

In this study, 171 men and women aged 50 and older were randomised to receive placebo or doses of either: potassium bicarbonate, sodium bicarbonate, or potassium chloride for 3 months. ‘We demonstrated that adding alkali in pill form reduced bone resorption and reduced the losses of calcium in the urine over a 3-month period,’ said Dr. Dawson-Hughes. ‘This intervention warrants further investigation as a safe and well tolerated supplement to reduce bone loss and fracture risk in older men and women.


Is the GI a key to unlocking a hidden addiction?
Doing something about the obesity epidemic is at the top of most public health agendas. Talk about budget blow out! The financial cost to the whole community of burgeoning waistlines is scary. New Zealand scientists from the University of Auckland explore the idea in Medical Hypotheses that addiction could be an important factor causing the obesity epidemic. They compare and contrast the evidence about nicotine addiction to food and GI and suggest that if high GI foods like corn flakes or white bread are the villain of the piece, ‘low GI equivalents may be the saviour’. The point of the study is really the public health implications of the theory. As the researchers point out: ‘Just as tax increases and control of advertising have proved effective in reducing the prevalence of smoking, similar strategies may help reduce the obesity epidemic.’

Dr Simon Thornley

Lead researcher Dr Simon Thornley, from Auckland Regional Public Health Service, said foods with a high GI caused blood glucose levels to spike, and this rush stimulates the same areas of the brain associated with addiction to nicotine and other drugs. He reports evidence showing that people who binged on high GI carb foods experienced loss of control, a compulsion to keep taking higher amounts to get the same ‘buzz’, and suffered withdrawal if they went ‘cold turkey’.

‘It's a novel idea that draws on strong evidence that glucose consumption influences levels of the feel-good chemical serotonin in the brain, says Sydney University’s Prof Jennie Brand Miller. ‘Although all foods take about 30 minutes to peak and the overall shape of the post-meal glycemia curve is similar for high, medium and low GI foods, high-GI foods peak and fall at substantially greater levels. Our recent study that explored the association between a food’s GI and the shape of the curve clearly suggests that to control high blood glucose after meals, carb quality (or its GI) and carb quantity both count (see the abstract). So the general message is say “low GI” with carb-rich foods as well as watching portion size.’

For more information about the ‘hidden addiction’ hypothesis email Simon Thornley.

What's New?

The Giveaway is now closed. Thanks for all the entries to the Shopper's Guide Giveaway. The winners will be notified by the publishers.



Healthy Indian Cooking for Diabetes
By Azmina Govindji and Sanjeev Kapoor
Published by Kyle Cathie in association with Diabetes UK
There’s no compromising on taste in this book of healthy traditional Indian dishes for people with type 2 diabetes. Dietitian Azmina Govindji and celebrity chef Sanjeev Kapoor address the serious problem of diabetes in the South Asian population (almost 20 million people are affected) with a unique book that provides dietary advice and 100 authentic recipes to help people with diabetes manage their blood glucose with the right foods, portion control and healthy cooking methods. Over the next few months, GI News will be sharing Azmina and Sanjeev’s recipes with readers.


For more information visit www.govindjinutrition.com

Australian Lifestyle Medicine Association Conference
The aims of the first annual conference are to:

  • Provide education in the practice of lifestyle medicine to health professionals;
  • Inform delegates of the latest scientific findings in lifestyle related health;
  • Initiate best practice for financial involvement in lifestyle medicine.
Check the website for details: www.alma-inc.com.au

When? 20-22 March 2009
Where? Manly Pacific Hotel, Sydney NSW Australia
Further information: Troy Grogan (troy.grogan@greatestasset.org)


Anonymous said...

I never know what the slow or low carbs are that are the best to eat! Its hard knowing what meals to prepare for my husband & I as diabetics!
I'm hoping this site helps.

GI Group said...

Hi Bev,
Here are some tips for lowering the GI of your diet. You may find it helpful to pick up a copy of the 2009 Shopper's Guide to GI Values, too.

10 tips for reducing the GI of your diet

* Aim to eat at least two serves of fruit and five serves of vegetables every day, preferably of three or more different colours. Tidbit: Fill half your dinner plate with veggies.
* If you are a big potato eater, either have one or two Nicola, Almera or tiny chat potatoes. Tidbit: Make ‘mash’ replacing half the potato with cannellini beans.
* Choose a low GI bread. Look for the GI Symbol or choose a really grainy bread, true sourdough bread or a soy and linseed bread.
* Replace high GI breakfast flakes (real glucose gushers) with low GI alternatives like natural muesli, traditional porridge oats or one of the lower GI processed breakfast cereals.
* Look for lower GI rices such as basmati, Doongara Clever Rice or Moolgiri medium grain rice and choose less processed foods or low GI wholegrains such as traditional rolled or steel-cut oats, or quinoa for porridge or pearl barley, buckwheat, bulgur, whole kernel rye, or whole wheat kernels.
* Eat legumes (beans, chickpeas and lentils) often – home cooked or canned.
* Include at least one low GI carb with every meal. You’ll find them in four of the food groups: fruit and vegetables; bread and cereals; legumes; low fat dairy or soy alternatives.
* Choose low GI snacks – fresh fruit, a dried fruit and nut mix, low fat milk or yoghurt.
* Vinegar and lemon or lime juices slow stomach emptying and lower your blood glucose response to the carbohydrate with which they are eaten. Tidbit: Get the salad habit and toss it in a vinaigrette dressing.
* Limit refined flour products – cookies, cakes, pastries, pies, crumpets, crackers, biscuits irrespective of their fat and sugar content.

Anonymous said...

Speaking of potatoes - I was reading something that suggested that potatoes be eaten hot, not cold as in a potato salad. Do cold potatoes become higher GI than if they were eaten hot?? Thank you in advance - K.

GI Group said...

Re potatoes -- here's an article from an earlier issue of GI News.

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.

Unknown said...

I am confused at your suggestion to regularly eat pulses. Before being diagnosed with T1D in 2007, pulses formed a major part of my diet - as I try to limit my carbohydrate intake to one or two portions per meal, I have now pretty well eliminated them - a third of a cup of lentils doesn't go very far. They may be low GI but they are not low in carbohydrates. I have reluctantly turned to a diet of vegetables/salad and fish, with red meat and chicken once a week. I would love toknow how to incorporate pulses into a very low carbohydrate diet

GI Group said...

Australian winners of the 2009 Shopper's Guide Giveaway.
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Karen (Ballarat, Vic. 3353)
Nerida (Beecroft NSW 2119)
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'R' (Charters Towers Qld 4820)

GI Group said...

Amy (Austin, TX 78723)
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GI Group said...

Dear CathyCarey1, We ran your pulses/legumes question by one of our dietitians who has personal experience of type 1 diabetes. Here's what she says:

'It sounds like you are following a low carbohydrate diet yet this is not necessary for type 1 diabetes. The recommendations for T1D are to follow a healthy diet with adequate amounts of carbs and to match insulin doses to carbohydrate intake. Obviously the amount of carbs is important but they don’t need to be significantly restricted, just balanced with the amount of insulin you take. Carbs are an important source of fuel for the body and a low carb diet is generally higher in fat and protein which may cause long term problems for people with diabetes. However, even on a lower carbohydrate intake, legumes are not a really high carb food due to their protein content. Around ½ cup of most cooked or canned legumes is equivalent to 1 serve (ie a slice of bread or ½ cup pasta or 1 potato) and since they are pretty filling due to their high fibre content, this amount is quite satisfying. They also have a very low GI so have less of an impact on BGLs than most other carb rich foods. If you are having 1-2 carb serves per meal you could easily incorporate legumes – some suggestions include adding chickpeas to a stir-fry, mashed cannellini beans in place of potato with meat and vegetables, a bean salad along with fish and salad or a bowl of lentil and vegetable soup.'