THE NEW ATKINS FOR A NEW YOU
Page 31
Understanding the role of carbohydrate restriction in the prevention and treatment of diabetes is especially important because of the enormous scope of the diabetes epidemic. Despite the best efforts of the traditional medical approach, which is based upon aggressive use of drugs, the tide of this disease continues to rise. According to the American Diabetes Association, the disease now affects 18.2 million people in the United States, but because the early stages of diabetes can be completely silent, 8 million of them are unaware that they have the disease. Nor are the numbers likely to improve soon. As other nations adopt a diet high in sugar and processed carbohydrates, the epidemic has escalated to involve 246 million people worldwide, with projections of 380 million by 2025.
UNDERSTANDING DLOOD SUGAR READINGS
The amount of glucose (sugar) in your blood changes throughout the day and night. Your levels vary depending upon when, what, and how much you have eaten and whether or not you’ve exercised. The American Diabetes Association (ADA) categories for normal blood sugar levels follow, based on how your glucose levels are tested.
Fasting blood glucose. This test is performed after you have consumed no food or liquids (other than water) for at least eight hours. A normal fasting blood glucose level is between 60 and 110 mg/dL (milligrams per deciliter). A reading of 126 mg/dL or higher indicates a diagnosis of diabetes. (In 1997, the ADA changed it from 140 mg/dL or higher.) A blood glucose reading of 100 indicates that you have 100 mg/dL.
”Random” blood glucose. This test may be taken at any time, with a normal blood glucose range in the low to midhundreds. A diagnosis of diabetes is made if your blood glucose reading is 200 mg/dL or higher and you have such symptoms of the disease as fatigue, excessive urination, excessive thirst, or unplanned weight loss.
Oral glucose tolerance. After fasting overnight, you’ll be asked to drink a sugar-water solution. Your blood glucose levels will then be tested over several hours. In a person without diabetes, glucose levels rise and then fall quickly after drinking the solution. If a person has diabetes, blood glucose levels rise higher than normal and don’t fall as quickly. A normal blood glucose reading two hours after drinking the solution is less than 140 mg/dL, and all readings in the first two hours must be less than 200 mg/dL for the test to be considered normal. Blood glucose levels of 200 mg/dL or higher at any time indicate a diagnosis of diabetes.
Hemoglobin A1c (HbA1c). This is a substance that goes up as a result of high blood glucose levels, and, once elevated, it stays up for a couple of months. Because blood glucose levels bounce around a lot depending on diet and exercise, the HbA1c test offers the advantage of smoothing out a lot of this variability. A level below 5.5 is considered good; a level above 6.5 indicates a diagnosis of diabetes.
As of this writing, the American Diabetes Association is intending to adopt the HbA1c test as a diagnosis for diabetes.
DIABETES AND INFLAMMATION: A CHICKEN-AND-EGG SITUATION?
The underlying cause of type 2 diabetes is a controversial topic. In general, diabetes is a disorder of carbohydrate metabolism caused by a combination of hereditary and environmental factors. The latter includes the composition of the diet, obesity, and inactivity. However, many people eat a poor diet and are sedentary but never develop obesity or diabetes. Similarly, some obese, sedentary people have normal blood sugar levels. Nonetheless, overall, obesity and inactivity increase an individual’s risk of developing diabetes, but some individuals seem more protected than others. This indicates that genetics play an important role in the development of the disorder. Another important factor is age: your body may tolerate bad behavior at age 30 but not necessarily at 60.
Your body uses the hormone insulin to trigger the movement of blood sugar into the cells, but, as you learned in the previous chapter, at high levels insulin also promotes metabolic syndrome, including excess fat storage, inflammation, and the formation of plaque in your arteries. Inflammation has increasingly become a topic of interest because people with type 2 diabetes typically have increased blood levels of inflammation biomarkers such as C-reactive protein (CRP), and this biomarker in turn accurately predicts who will later develop such complications of type 2 diabetes as heart disease, stroke, and kidney failure.1
More important, however, when large populations of adults without diabetes are screened for CRP levels and then followed for five to ten years, the quarter of the population with the highest levels has two to four times the likelihood of subsequently developing diabetes.2 What this means is that inflammation comes before the overt signs of diabetes develop. In other words, inflammation looks less like an effect of diabetes and more like an (if not the) underlying cause. Coming back to our analogy of carbohydrate as a bully, it’s simple but appealing to think that dietary carbohydrates repeatedly “bruise” the body. Further, it would seem that some people respond to this bruising by becoming inflamed, and this inflammation eventually results in damage that causes cells to become insulin-resistant and organs to eventually fail.
So how does this simple analogy help us understand something as complex as the underlying cause of type 2 diabetes? Well, take away the bully, and the bruising stops. Right? In the previous chapter we gave you strong evidence that carbohydrate restriction in people with metabolic syndrome (aka prediabetes) results in a sharp reduction in the biomarkers of inflammation. Now we’ll show you that type 2 diabetics consuming a low-carb diet experience improvements in blood sugar, blood lipids, and body weight—sometimes dramatically so.
A LOOK AT THE RESEARCH
There are several different types of studies used to understand the effect of eating different foods on human health. In previous decades, scientists tended to rely on observational studies of what people ate and how that affected their long-term health (nutritional epidemiology), but prospective clinical trials are considered more accurate. Studies on individuals in an “inpatient” clinical research ward provide tight control over what people eat, but they tend to be limited to a week or two, during which research subjects remain hospitalized, with a few notable exceptions.
In other studies, researchers give subjects food to take home to eat. However, there’s no assurance that people won’t eat other food in addition to the supplied meals. Finally, another type of research involves instructing people to buy and eat certain foods and return for instruction and support—often over a period of several years. These “outpatient” or “free-living” studies tell us a lot about whether a certain diet is sustainable in the “real-world” setting. But the interpretation of such studies is limited because people don’t necessarily follow the dietary instructions. Here are some examples of studies that have shown that the Atkins Diet is a safe and effective treatment for type 2 diabetes.
INPATIENT STUDIES
In a pioneering study done thirty years ago, seven obese type 2 diabetics were placed on a very-low-calorie ketogenic diet, first as inpatients and later as outpatients.3 Initially, these subjects had fair-to-poor blood glucose control despite the fact that they were already taking 30 to 100 units of insulin per day. Within twenty days of starting the low-carbohydrate diet, all the subjects were able to discontinue their insulin injections. Nonetheless, their blood glucose control improved, as did their blood lipid profiles. The authors noted that blood glucose control improved much more rapidly than did the rate at which they lost weight, indicating that carbohydrate intake was the primary determinant of glucose control and insulin requirement rather than obesity itself.
In a 2005 inpatient study ten obese people with type 2 diabetes were fed their usual diet for seven days, followed by a low-carbohydrate diet (the Induction phase of Atkins) of 20 grams of carbs a day for fourteen days.4In both cases, subjects were allowed to choose how much they ate, so the only change after the first week was eliminating most carbohydrate foods. Because this study took place in a research ward, the researchers were able to document the subjects’ total food intake. They found that when subjects followed the low-carb diet, they continued to eat about the same amo
unt of protein and fat as before, even after two weeks of carb restriction and although they could have eaten more protein and/or fat to make up for the missing carbohydrate calories if they desired. This means that they naturally ate fewer calories when carbs were restricted. In addition to losing weight, the subjects also showed improvements in their blood glucose and insulin levels. Many were able to eliminate their medications, and their insulin sensitivity improved by 75 percent on average, similar to the observations of the 1976 study cited above. More important, this recent study showed that instructing people to limit their grams of carbohydrate (without restricting calories or portion size) resulted in their eating less food and rapidly improving their insulin sensitivity.
OUTPATIENT STUDIES
A recent outpatient study compared a low-carbohydrate diet to a portion-controlled, low-fat diet in seventy-nine patients over a three-month period.5 After three months, subjects in the low-carb group were reportedly consuming 110 grams of carbohydrate per day (the upper range of the Atkins Lifetime Maintenance phase). Compared to the low-fat group, the low-carb group had improvements in glucose control, weight, cholesterol, triglycerides and blood pressure. In addition, more people in the low-carb group were able to reduce medications than those in the low-fat group.
Another, very recent outpatient study compared the Induction phase of Atkins (20 grams of carbohydrate daily) to a reduced-calorie diet (500 calories a day below their previous intake level, low in fat and sugar but high in complex carbs) over a six-month period.6 They found greater improvements in blood sugar levels and greater weight loss in the Atkins Induction group. What was especially exciting, however, was that individuals who were taking insulin often found the beneficial effects of the low-carb diet quite powerful. Subjects taking from 40 to 90 units of insulin before participating in the study were able to eliminate insulin altogether, while also improving glycemic control. These results were similar to the inpatient studies described above.
And finally, the Kuwaiti low-carb study cited in chapter 1 included thirty-five subjects whose blood glucose was elevated at the start of the study. The average value for this group returned into the normal range within eight weeks of following the low-carb diet, and at fifty-six weeks, this group’s average fasting blood glucose had been reduced by 44 percent.
In summary, these five studies, in a variety of settings, all showed dramatic improvements in blood glucose control and blood lipids in type 2 diabetics consuming a low-carb diet. When these studies included a low-fat, high-carb comparison group, the low-carb diet consistently showed superior effects on blood glucose control, medication reduction, blood lipids, and weight loss. Weight loss is particularly important because treatment goals for patients with type 2 diabetes always emphasize weight loss if the individual is overweight, yet the drugs used to treat diabetics almost all cause weight gain. So let’s look at this briefly, as the ability to deliver improved blood sugar control and weight loss distinguishes a low-carb approach from all other nonsurgical treatments for type 2 diabetes.
WEIGHING THE OPTIONS: COMMON SIDE EFFECTS OF MEDICATION
On its surface, the management of type 2 diabetes seems pretty easy: just get your blood glucose back down into the normal range. But insulin resistance characterizes this form of diabetes; put simply, the glucose level “doesn’t want to go down.” This means that the body is less responsive to the most powerful drug used to treat it: insulin. So the dose of insulin that most type 2 diabetics are prescribed is very high. Moreover, because insulin not only drives glucose into muscle cells but also accelerates fat synthesis and storage, weight gain is usually one side effect of aggressive insulin therapy.7 Other pills and injected medications have been developed to reduce this effect, but on average, the harder one tries to control blood glucose, the greater the tendency to gain weight.8 The other major side effect of attempting to gain tight control of blood sugar is driving it too low, causing hypoglycemia, which causes weakness, shakiness, confusion, and even coma. If these symptoms appear, the advice is to immediately eat a lot of sugar to stop the symptoms, which jump-starts the blood sugar roller coaster all over again. Interestingly, once type 2 diabetics complete the first few weeks of the Atkins program, they rarely experience hypoglycemia. That’s because of the body’s adaptation to burning fat for most of its fuel during carb restriction, in concert with the ability to reduce or stop most diabetic medications (including insulin) within a few days or weeks of starting the Atkins Diet.
So why isn’t it good enough just to cut back on one’s calories without cutting back on carbs? It’s true that going on a diet and losing weight typically improve diabetes control. Well, first of all, dieting won’t necessarily result in weight loss, and any weight loss may not be sustained. Second, even weight loss is usually not enough to significantly reduce medication dosage. Finally, since diabetic drugs still produce side effects and appetite stimulation, losing weight on a standard diet is a difficult tightrope for a diabetic to walk.
Once you understand this tightrope of weight loss during drug treatment—some would call it a Catch-22—it’s easier to appreciate the advantage of using the Atkins Diet to manage type 2 diabetes. When you remove added sugar, significantly reduce carb intake overall, and confine your consumption primarily to the foundation vegetables allowed in Induction, your insulin resistance rapidly improves, and blood glucose control improves—usually dramatically. Additionally, most people find that they can stop or substantially reduce their diabetes medications. As a result, the path to meaningful weight loss changes from a tightrope to a wide road. As long as you stay within your carb tolerance range, you should be able to navigate your way to health.
IF AND WHEN TO EXERCISE
You might be familiar with many of the potential health benefits of exercise, but you probably don’t know that exercise has insulinlike effects. This is relevant for type 2 diabetics with insulin resistance, because performing just a single bout of exercise improves insulin resistance for several hours. A number of studies have shown that regular exercise improves blood sugar control, even if it doesn’t significantly improve weight loss.9 Because weight loss is so difficult for people with type 2 diabetes and because doctors have little else to offer (other than drugs) in the way of effective remedies, exercise is always near the top of the list of official guidelines.
Given this information, simple logic dictates that we should tell everyone with diabetes to get out and exercise. But not so fast. First, exercise holds an exalted position in diabetic treatment because the usual diets almost always fail. We need to consider what role exercise should play if the tables are turned and you have access to a diet like Atkins that almost always “works” and that simultaneously causes insulin resistance and blood sugar control to improve significantly. Unfortunately, we don’t yet have the perfect answer. Yes, we’ve proved that once people adapt to the Atkins Diet, they’re capable of lots of exercise. But no one has done a study of diabetics on Atkins in which some of them exercise and some of them don’t, to prove that adding exercise to an already successful diet improves blood sugar control or increases weight loss enough to justify the added effort.
Second, if you’re diabetic, you’re at increased risk for heart attack, and most people with type 2 diabetes are overweight (at least, before they start Atkins). So if you were offered the choice of either starting the program and exercising at the same time, or alternatively starting Atkins first, getting your blood sugar under control, reducing or stopping medications you might be taking for diabetes, and getting some weight off your ankles, knees, hips, and lower back, which would you choose?
Clearly, the key question is not really if but when. The Atkins Diet opens the door for you to exercise, and exercise has a lot of benefits other than weight loss (and may even improve your blood sugar control). As we’ve said previously, if you’re already physically active, keep it up, being careful not to overdo it while you’re adapting to fat burning in the first few weeks. But if it’s been a while
since you did much of anything vigorous, consider giving yourself a few weeks or months to unburden your heart and joints before taking on a 10K run or trying to burn out the treadmill or pump iron at the gym.
THE CURRENT OFFICIAL GUIDELINES
Okay, we’ve explained how Atkins offers unique benefits to someone with type 2 diabetes. So why isn’t everyone with the disorder doing it? The answer is that the low-fat-diet fad of the last forty years, backed by the food industry and government-sanctioned committees, has taken a long time to run its course. Only with the recent research we’ve cited in the last few chapters has the mainstream medical community begun to be receptive to the value of low-carbohydrate diets. Standard treatment guidelines are beginning to reflect this change. This is where we stand today.
The goal of medical nutrition therapy for type 2 diabetes is to attain and maintain optimal metabolic outcomes, including:
• Blood glucose levels in the normal range or as close to normal as is safely possible to prevent or reduce the risk for complications of diabetes
• Lipid and lipoprotein profiles that reduce the risk for blood vessel disease (i.e., blockage of blood flow to your heart, brain, kidneys, and legs)
• Blood pressure levels that reduce the risk of developing vascular disease
The American Diabetes Association (ADA) has acknowledged the use of a low-carbohydrate diet in achieving these goals in its 2008 guidelines, which include:10
• Modest weight loss has been shown to improve insulin resistance in overweight and obese insulin-resistant individuals.
• Weight loss is recommended for all overweight individuals who have or are at risk for the disease.
• Either low-carbohydrate or low-fat calorie-restricted diets may be effective for weight loss in the short term (up to one year).
• Patients on low-carbohydrate diets should have their lipid profiles, kidney function, and protein intake (for those with kidney damage) monitored regularly.