Good carbs – bad carbs

I have not ranted on this subject for a long time (malpractice, the insurance industry and the pharmaceutical industry kept getting in the way). This article stimulated my interest. For new readers, just search on “glycemic” and you will find a number of previous rants on this subject. Good carb, bad carb? Experts debate labels

The debate involves an idea called the glycemic index. It is a way of rating how quickly carbohydrates are digested and rush into the bloodstream as sugar. Fast, in this case, is bad. In theory, a blast of sugar makes insulin levels go up, and this, strangely, leaves people quickly feeling hungry again.

The debate over whether every person who puts food in his mouth should know about this is fervid even for the field of dietary wisdom, where fierce opinions based on ironclad beliefs and sparse data are standard.

Despite its detractors, the idea seems to be gaining momentum, in part because it is offered as scientific underpinning by the authors of a variety of popular diet schemes, mostly of the low-carb variety. However, some painstakingly argue that the glycemic index is just as important for the carbohydrate-loving brown rice aficionado as it is for the most carbo-phobic, double-bacon-cheeseburger-hold-the-bun Atkins follower.

The glycemic index refers to the speed of absorption and conversion to glucose. The higher the glycemic index the faster. High is bad, low is good.

The idea has already entered the scientific mainstream in much of the world and is endorsed by the World Health Organization, but it remains deeply controversial in the United States. It is dismissed by some of the country’s weightiest private health societies, including the American Heart Association and the American Diabetes Association.

And if the AHA and ADA dismiss the idea, then we have no major campaigns to educate the public. Without these influential organizations, we are unlikely to have food labelled for glycemic index (or even better glycemic load).

The GI of at least 1,000 different foods has been measured, in the process knocking down many common-sense dietary beliefs. For instance, some complex carbohydrates are digested faster than the long demonized simple carbs. Foods such as white bread and some breakfast cereals break down in a flash, while some sweet things, like apples and pears, take their time.

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To make matters even more confusing, the glycemic index measures only the carbohydrate in food. Some vegetables, such as carrots, have quite high GIs, but they don’t contain much carb, so they have little effect on blood sugar.

Therefore, some experts prefer to speak of food’s glycemic load, which is its glycemic index multiplied by the amount of carb in a serving. Considered this way, a serving of carrots has a modest glycemic load of 3, compared with 26 for an unadorned baked potato.

So now you understand the concept. We theoretically want to decrease glycemic load. The theory goes like this: the lower the glycemic load, the longer you stay satisfied. Therefore, you are less hungry at your next meal. Some research suggests this theory works.

In one, he tested the idea that a high-GI breakfast makes people hungrier at lunch. A dozen obese boys were fed three different breakfasts, all with the same calories – a low-GI vegetable omelet and fruit, medium-GI steel-cut oats or high-GI instant oatmeal.

At noon, they could eat as much as they wanted. Those who started the day with instant oatmeal wolfed down nearly twice as much as those getting the veggie omelet.

Ludwig says overweight people do not need to starve themselves. On a low-GI diet, they can eat enough to feel satisfied and still lose weight.

In a pilot study, he tested this on 14 overweight adolescents. They were put on two different regimens – a standard low-cal, low-fat, high-carb diet and a low-GI plan that let them eat all they wanted. After one year, the low-GI volunteers had dropped seven pounds of pure fat. The others had put on four. Now he is repeating the study on 100 heavy teenagers.

Even such small experiments have been rare. Most support for the idea comes from big surveys that follow people’s health and diets over time. Some of these show that those who consistently favor low-GI fare are less likely to become overweight or to get diabetes and heart disease.

The evidence is strong enough for authors of some popular diet books, who use the glycemic index as one of their primary rationales. “It’s a new unifying concept that brings nutritional habits out of the dark ages and says it’s all about the numbers,” says Barry Sears, author of the Zone series of diet books. “It says diet does not have to be based on philosophy. It can be based on hard science.”

Major U.S. health organizations are less impressed. Ludwig expects this to change, in part because paying attention to the glycemic index can help everyone choose healthier carbs, whether they go low-fat or high.

But that seems unlikely any time soon at the heart association. The head of its nutrition committee, Dr. Robert Eckel of the University of Colorado, says the theory that high-GI foods make people hungry is “ridiculous” and argues that a scientific case can be made for just the opposite.

So now you see the nutritional debate. I believe the glycemic load proponents’ side.

A diagnostic dilemma

Dr. Lisa Sanders writes regularly for the NY Times magazine. Each case that she presents makes one think, and generally teaches a good lesson. Hip and Buttock Pain, Difficulty Walking, Normal X-Rays

The middle-aged man limped slowly from the waiting room to the examining room. His normally tanned face was nearly gray with the pain and effort this simple act entailed. His physician, Dr. Andre Sofair, had called that day and asked him to come in after hearing that he’d been in the emergency room twice in the past two days because of this pain.

It started four days earlier, the man said. At first the pain was an ache, a pressure in his left hip and buttock. ‘’But soon it changed. I can’t even describe it,’’ he told me later. ‘’It was like –’’ He stopped and gripped his thick fist tightly, crushing his knuckles until they were white. ‘’And every day it’s worse.’’

Although walking was very painful, he could sit or lie comfortably – so long as he didn’t move. It was hard for him to locate the pain exactly. He’d never had a pain like this before, he said. And he hadn’t engaged in any physical activity that may have injured his back. He’d had no fevers, nausea or vomiting.

The physician knew the man and his history well. At 53, the patient had quite a few medical problems: diabetes, hypothyroidism and an abnormality in his bone marrow that led to anemia. He’d recently been released from the hospital, where he’d been treated for a bacterial infection. Still, he lived a pretty active life, and the doctor had never heard him complain.

The doctor examined him carefully. His normally tidy hair was uncombed, and his handlebar mustache was well trimmed, but the face behind it was pale and unshaven. The man’s temperature and blood pressure were normal. His heart was slow and regular, his lungs clear. His back itself was straight and symmetrical. There was no rash, no redness, no swelling of the back or the hip. The doctor felt along the bony prominences that delineate the spine, looking for tender points, and found none. The muscles that flank the spine felt firm and smooth.

The remainder of the article discusses the evaluation, the diagnosis and the treatment. I like to “play along” on these presentations and see if I can figure out the problem myself. You might want to at least think through the presentation prior to reading the entire article.

PTSD

Working at a VA I see many patients who carry the label of PTSD. Some of them clearly have this disorder. This article raises a healthy skepticism about making this a psychiatric diagnosis. Is Trauma Being Trivialized?