Low-glycemic diet seen to reverse diastolic dysfunction of diabetes

Vienna, Austria - A diet that was short on carbohydrates and long on protein, given to diabetic patients engaged in a supervised exercise and weight-loss program, appeared not only to cut proinsulin levels and postprandial glucose and triglyceride levels, it seemed to improve LV diastolic function [1].

In the study that compared the "low-carb" diet to a traditionally recommended low-fat diet, the one designed to flatten out resulting insulin and glucose curves also allowed them to take far fewer oral diabetes medications and apparently cut both systolic and diastolic pressures. The low-fat diet had no apparent effect on diastolic function or med use or on blood pressures.

Prof Helene von Bibra

On the other hand, the two diets led to about the same declines in weight and waist circumference and lipoprotein-cholesterol levels, reported Prof Helene von Bibra (Technical University Munich, Germany) here at the Prediabetes and the Metabolic Syndrome 2013 Congress.

Many patients with insulin resistance, diabetes, or both have subclinical diastolic dysfunction, with severe prognostic implications if it becomes symptomatic, von Bibra reminded heartwire. About 65% of the 32 patients in the study had abnormal diastolic function as defined echocardiographically by low early diastolic myocardial velocity. That measure in most cases nearly normalized after the low-carb diet, but not after the low-fat diet, she said.

Of 32 overweight or obese diabetic patients (mean body-mass index, 34) without cardiac disease who were engaged in a "rehabilitation program in order to lose weight" that included two hours of supervised aerobic exercise per day, half followed a low-glycemic diet (25% carbohydrate, 45% fat, 30% protein) and the other half a low-fat diet (55% carbohydrate, 25% fat, and 20% protein) for three weeks. The diets provided the same amount of calories. Those on the low-fat diet then switched to the low-glycemic diet for an additional two weeks. Cardiac function by echo and metabolic parameters were assessed daily before and after a 400-kcal breakfast.

From baseline to three weeks, patients on the low-carb diet reduced their use of conventional oral antidiabetic medication by 86%. Those on the low-fat diet reduced them by only 6% by the end of three weeks, but intake went down another 57% by the end of their two-week low-glycemic diet phase. "And still they had improvements in glucose," von Bibra said. Medications other than oral ones for diabetes, such as antihypertensive drugs, were not changed in anyone during the study.

Laboratory and echo changes in overweight/obese diabetic patients assigned to low-glycemic (n=16) and low-fat (n=16) diets

Initial assigned diet	Baseline	3 wk	2 wk after crossover to low-carb	p
Low-glycemic
Triglycerides (mg/dL)	150	111	—	<0 .005="" br="">
Postprandial glucose (mg/dL)	141	125	—	<0 .04="" br="">
E' (cm/s)	9.5	10.4	—	<0 .03="" br="">
Low-fat
Triglycerides (mg/dL)	208	194	138	<0 .003="" 3="" baseline="" br="" vs="" wk="">
Postprandial glucose (mg/dL)	168	137	127	<0 .008="" baseline="" br="" vs="">
E' (cm/s)	10.8	10.7	11.4	<0 .02="" 3="" br="" vs="" wk="">

E'=early diastolic myocardial velocity by tissue-Doppler echocardiography

The gains in diastolic function probably were not independently related to the associated blood-pressure reductions; rather, she proposed, they reflected improvements in myocardial energy utilization on the low-glycemic diet. Insulin resistance can lead to diastolic dysfunction via several pathways, she noted, but the most prominent seems to be myocardial energy deficiency secondary to microvascular dysregulation and mitochondrial imbalances of glucose vs fat oxidation.

APRIL 22, 2013 Steve Stiles

The GI Symbol and Your Food Labels

What is the GI Symbol?

The Glycemic Index Symbol is a powerful tool for quickly and reliably making healthy food choices when grocery shopping. It’s your guarantee that the GI value stated near the nutrition information label is accurate. Foods with the GI Symbol are healthy in other ways, too. To be approved to carry the GI Symbol, foods must be a good source of carbohydrate and meet a host of other nutrient criteria including calories/kilojoules, total and saturated fat, sodium (salt), and where appropriate fibre and calcium.

Why put the GI Symbol on food labels?

The GI Symbol makes healthy choices easy choices. Most of us find it hard to work out what all of the different nutrition claims and nutrition information means, and just because a food may claim to be low GI, it does not mean that it has been tested correctly, if at all. Foods that carry the GI Symbol meet strict nutrient criteria ensuring they are healthy choices, and the GI value is certified as accurate. Managing your blood glucose levels is one of the keys to lifelong health. Choosing low Glycemic Index carbohydrates – the ones that produce smaller fluctuations in your blood glucose and insulin levels – reduces your risk of type 2 diabetes and cardiovascular disease. It’s also one of the keys to sustainable weight loss. Low GI eating is for everybody. The GI Symbol helps you put those smart low GI carbohydrate foods into your shopping trolley and lower the overall GI of your diet. © 2013 THE GI FOUNDATION, ALL RIGHTS RESERVED

10 Tips for Reducing the GI of Your Diet

1. Pile half your dinner plate high with vegetables or salad Aim to eat at least five servings of vegetables (this doesn’t include the starchy ones like potatoes, sweet potatoes or sweet corn) every day, preferably of three or more different colors. 2. Be wise with your potatoes If you are a big potato eater and can't bear the thought of giving them up, you don't have to. Just choose wisely, and be careful with the quantity. Choose one or two medium-sized low GI potatoes such as Carisma, or a lower GI potato such as Nicola or Marfona or have one or two baby new potatoes with a small cob of corn or make a cannellini bean (they are white beans) and potato mash replacing half the potato with cannellini beans. Don't be afraid of trying other starchy vegetables like sweet potato, yams or taro - steamed, roasted or mashed. 3. Swap your bread Instead of high GI white and wholemeal breads, choose a really grainy bread where you can actually see the grains, granary bread, stone-ground wholemeal bread, real sourdough bread, soy and linseed bread, pumpernickel, fruit loaf or bread made from chickpea or other legume-based flours. 4. Replace those high Glycemic Index crunchy breakfast flakes These refined breakfast cereals spike your blood glucose and insulin levels. Replace them with smart carbs like natural muesli or traditional (not instant) porridge oats or one of the lower GI processed breakfast cereals that will trickle fuel into your engine. 5. Make your starchy staples the low GI ones Look for the low GI rice's, serve your pasta al dente, choose less processed foods such as large flake or rolled oats for porridge or muesli and intact grains such as barley, buckwheat, bulgur, quinoa, whole kernel rye, or whole wheat kernels and opt for lower GI starchy vegetables. 6. Learn to love legumes (pulses) Include legumes like beans, lentils and chickpeas in your meals two or three times a week, more often if you are vegetarian. Add chickpeas to a stir-fry, red kidney beans to a chili, a 4-bean salad to that barbecue menu, and beans or lentils to a casserole or soup. 7. Develop the art of combining No need to cut out all high GI carbs. The trick is to combine them with those low GI tricklers to achieve a moderate overall GI. How? Lentils with rice (think of that delicious classic Italian soup), rice with beans and chili (go Mexican), tabbouleh tucked into pita bread (with falafels of course and a dash of hummus), baked beans on toast or piled on a jacket-baked potato for classic comfort food. 8. Incorporate a lean protein source with every meal Eat lean meat, skinless chicken, fish and seafood, eggs, milk, yogurt or cheese, or legumes and tofu if you are vegetarian. The protein portion should make up around a quarter of the plate/meal. 9. Tickle your taste buds Try vinaigrette (using vinegar or lemon juice with a dash of extra virgin olive oil) with salads, yogurt with cereal, lemon juice on vegetables like asparagus, or sourdough bread. These foods contain acids, which slow stomach emptying and lower your blood glucose response to the carbs in the meal. 10. Go low GI when snacking If it is healthy and low GI, keep it handy. Grab fresh fruit, dried fruit, or fruit and nut mix, low fat milk and yogurt (or soy alternatives). Limit (this means don't buy them every week) high GI refined flour products whether home baked or from the supermarket such as cookies, cakes, pastries, crumpets, crackers, biscuits, irrespective of their fat and sugar content. These really are the 'keep for the occasional treat' foods. Keep your eye on the serving size. Remember portion caution with carb-rich foods such as rice, al dente pasta and noodles, potatoes etc. Eating a huge amount of these foods, even of the low GI variety, will have a marked effect on your blood glucose. A cup of cooked noodles or al dente pasta or rice plus plenty of mixed non-starchy vegetables and a little lean protein can turn into 3 cups of a very satisfying meal. © 2013 THE GI FOUNDATION, ALL RIGHTS RESERVED