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 Health Benefits of Low GI Eating

More on the Glycemic Index as it pertains to your diet . . . . .

The scientific evidence supporting the health benefits of a healthy low GI diet is overwhelming. We know from over 30 years of research from around the world that healthy low Glycemic Index diets: Help to fill you up and keep you feeling satisfied for longer, avoiding over eating or too much snacking. Lower your insulin levels which makes fat easier to burn and less likely to be stored. Help you to lose body fat and maintain lean muscle tissue. Reduce your triglycerides, total and 'bad' (LDL) cholesterol. Increase your levels of 'good' (HDL) cholesterol. Reduce your risk of developing type 2 diabetes. Help to manage your blood glucose levels and reduce your risk of developing diabetes complications. Reduce your risk of developing cardiovascular disease. Reduce your risk of developing some cancers Reduce your risk of developing certain eye diseases. Improve your skin Sustain your energy levels longer, improving both mental and physical performance. Low GI eating really is for everyone.

Knowing the GI of foods is of particular value to people with diabetes who need to manage their blood glucose levels carefully. Perhaps unsurprisingly, diabetes organizations such as Diabetes Australia, Canadian Diabetes Association, European Association for the Study of Diabetes, Juvenile Diabetes Research Foundation and the South African Diabetes Association encourage an understanding and use of GI in meal planning. However, lowering the GI of your diet can also lead to better health  through improved heart health and helping to manage appetite. Health and nutrition authorities from around the world recommend that everyone use the GI as a tool when looking for healthy food choices: In 1998, the World Health Organization and Food and Agriculture Organisation recommended that the glycemic index of carbohydrate foods be a factor in food choice. The Dietary Guidelines for Australians specifically recommend the consumption of lower GI cereal-based foods: "Eat plenty of cereals, breads and pastas — preferably wholegrain ... with a lower glycemic index ... ". © 2013 THE GI FOUNDATIOn

Defining Low, Medium and High Glycemic Foods

Why might the low Glycemic Index Number of your favorite Snickers bar still not be the healthiest choice for you?

Determining whether a food is high- or low-glycemic is pretty straightforward. The glycemic index is broken into high-, medium-, and low-glycemic foods. High-glycemic-index foods have the quickest blood sugar response; low-glycemic-index foods have the slowest. Here are the measurements on a scale of 0 to 100:

• Low glycemic index: 55 or less
• Medium glycemic index: 56 to 69
• High glycemic index: 70 or greater

Keep in mind that high-glycemic foods aren’t necessarily unhealthy foods. Similarly, low-glycemic foods aren’t always healthy. The glycemic index simply lets you know how quickly your blood sugar will rise from eating that food.

The following table shows the glycemic index numbers and measurements of some popular foods. Some foods fall right into line with what you probably predicted: Brown rice is a low-glycemic food, and basmati white rice and spaghetti are medium-glycemic foods. But it’s not always that clear-cut. Notice how jasmine rice has a significantly higher glycemic index number than basmati rice even though both types of rice are white? This is where specific types of products vary. Even though foods of the same type may appear the same, each variety can produce a different blood sugar response for many reasons.

The Glycemic Lowdown on Some Popular Foods

Food	Glycemic Index Number	Measurement
Peanut M&M’s	33	Low
Snickers bar	43	Low
Brown rice	48	Low
Whole-wheat bread	52	Low
Basmati white rice	57	Medium
Spaghetti	58	Medium
Plain bagel	69	Medium
Watermelon	72	High
Jasmine rice	89	High
Baked potato without skin	98	High

Note that some candy has low glycemic content, whereas baked potatoes and watermelons have some of the highest. This doesn’t mean that candy is suddenly healthier for you than a potato or fruit. Baked potatoes and watermelons are high in many different vitamins, minerals, and fiber as well as glycemic content, and candy is high in lots of undesirable categories such as calories — and empty calories at that!

By Meri Raffetto from The Glycemic Index Diet For Dummies