THE NEW ATKINS FOR A NEW YOU
Page 30
LDL CHOLESTEROL
The main aim of low-fat diets and many drugs such as statins is to lower concentrations of LDL cholesterol. On average, low-fat diets are more effective at lowering LDL cholesterol levels than are low-carbohydrate diets. But before you chalk up this marker to low fat, consider that simply lowering LDL cholesterol by restricting dietary fat doesn’t reduce your risk of developing heart disease.28 Why? An obvious reason is that low-fat diets exacerbate other risk factors; they increase triglycerides and reduce HDL cholesterol. But there’s another explanation that relates to the LDL particles themselves. Not all forms of LDL particles share the same potential for increasing heart disease. Within the category labeled LDL, there is a continuum of sizes, and research shows that smaller LDL particles contribute more to plaque formation in arteries (atherosclerosis) and are associated with a higher risk for heart disease. Although low-fat diets may decrease total LDL concentration, they tend to increase the proportion of small particles,29 making them more dangerous. However, going in the other direction, numerous studies indicate that replacing carbohydrate with fat or protein leads to increases in LDL size.30 Therefore, it’s clear that carbohydrate intake is strongly and directly related to promoting the forms of LDL that contribute to arterial plaque formation,31 whereas replacing carbohydrates in the diet with fat, even saturated fat, seems to promote the forms of LDL that are harmless.
INFLAMMATION
As discussed above, when inflammation stays elevated because of a repeated insult such as a poor diet, it spells bad news. Researchers now appreciate the importance of this ongoing low-grade condition in contributing to many chronic health problems, including diabetes, heart disease, and even cancer. We typically think of inflammation in respect to fighting off bacteria and viruses. However, other substances, including excess carbohydrates and trans fats, can contribute to inflammation. A single high-carbohydrate meal can lead to increased inflammation.32 Over time, eating a high-carbohydrate diet can lead to increased markers of inflammation.33
What about low-carbohydrate diets? Levels of CRP, a cytokine marker for inflammation, have been shown to decrease by approximately one-third on the Atkins Diet.34 In subjects with higher levels of inflammation, CRP levels decreased more in response to a low-carbohydrate diet than to a fat-restricted diet.35 A recently published study compared subjects with metabolic syndrome on a low-fat diet to those who were consuming a very-low-carbohydrate diet. The low-carb group showed a greater decrease in eight different circulating inflammatory markers compared to the low-fat group.36 These data implicate dietary carbohydrate rather than fat as a more significant nutritional factor contributing to inflammation, although the combination of both increased fat and a high carbohydrate intake may be particularly harmful.
The anti-inflammatory effects of the omega-3 fats EPA and DHA have been shown in cell culture and animal studies, as well as in trials using humans.37 These effects partially explain why these fats appear to have widespread health-promoting effects, especially in reducing the risk of heart disease and diabetes. Several hundred studies have demonstrated the cardioprotective effects of fish oil, and numerous review studies have summarized this body of work.38 That’s why we recommend regular consumption of fatty fish or use of a supplement containing EPA and DHA.
VASCULAR FUNCTION
An early event in heart disease, vascular dysfunction is now considered part of metabolic syndrome because of its likely origins in insulin resistance in cells that line the interior artery walls.39 An ultrasound technique that measures the ability of an artery in the arm (the brachial artery) to dilate detects the proper functioning of blood vessels.40 In previous studies, a high-fat meal has been shown to temporarily impair dilation of the brachial artery.41 The adverse effects of single meals high in fat, especially saturated fat, on lipid levels after a meal42 and on vascular and inflammatory functions have been used as evidence to discourage low-carbohydrate diets. The test subject’s prior diet history, however, has a fundamentally important effect on the metabolic response to meals. For example, research has repeatedly shown that adaptation to a very-low-carbohydrate diet results in a substantial reduction in the triglyceride response to a high-fat meal.43 This means that studies that show short-term harmful effects of a high-fat meal on vascular function may show very different results after subjects are adapted to a low-carbohydrate diet.
When the effects of a high-fat meal on vascular function are assessed in subjects with metabolic syndrome who consumed a high-fat, very-low-carb diet,44 there is a marked decrease in the triglyceride response to the high-fat meal. In contrast, control subjects consuming a low-fat diet showed little change. After twelve weeks on a very-low-carbohydrate diet, subjects showed improved vascular function after a high-fat meal compared to a control group of subjects who consumed a low-fat diet.
THE ATKINS DIET IS GOOD MEDICINE
A series of low-carbohydrate-diet studies show that improvement in metabolic syndrome is intimately connected with controlling carbohydrate consumption.45 Although metabolic syndrome can manifest in various ways, the nutritional benefits of a low-carbohydrate diet hold the promise of improving all the syndrome’s features. Most physicians would treat each symptom individually, with the result that an individual might be taking multiple medications, increasing both the expense and the chance of developing side effects. Because having metabolic syndrome means you’re on the fast track to diabetes and heart disease, getting all of its components under control is a unique benefit of the Atkins Diet. In the next chapter, you’ll learn that these same dietary modifications can also reduce the likelihood of developing type 2 diabetes or even reverse its course, as evidenced by our final Success Story.
SUCCESS STORY 10
WHEN PROFESSIONAL AND PERSONAL WORLDS COLLIDE
His self-diagnosis of diabetes launched the Canadian physician Jay Wortman on a personal odyssey of discovery and recovery. It also spurred a professional quest to push the boundaries of diabetes management at a time when the disease is becoming a global health crisis.
VITAL STATISTICS
Current phase: Lifetime Maintenance
Daily Net Carb intake: 20–30 grams
Age: 59
Height: 5 feet, 9 inches
Before weight: 185 pounds
Current weight: 160 pounds
Weight loss: 25 pounds
Current blood sugar: Under 6 mmol/Ll (108 mg/dL)
Current HbAlc: 5.5%
Former blood pressure: 150/95
Current blood pressure: 130/80
Current HDL cholesterol: 91 mg/dL
Current LDL cholesterol: 161 mg/dL
Current triglycerides: 52.4 mg/dL
Current total cholesterol: 272 mg/dL
Current C-reactive protein: 0.3 mg/dL
What is your background?
As a physician who has focused on aboriginal health, I was acutely aware of the high rates of diabetes, as well as obesity and metabolic syndrome, in this population. These epidemics were devastating aboriginal communities and incurring huge costs for health care services. When I traveled to the affected communities, there was almost a feeling that the situation was hopeless. Even in communities with extra resources and research programs, we weren’t able to reverse the terrible trend.
Did you have a family history of diabetes?
I grew up in a small village in northern Alberta, Canada. Some of my ancestors were settlers in the Hudson Bay area and had intermarried with aboriginal peoples. Both my maternal grandparents developed type 2 diabetes, as did my mother and other close relatives. The aboriginal genetic tendency toward this disease had slowly snaked its way up through my family tree to bite me.
How did you react to this realization?
I was stunned. As a physician, you somehow believe that you’re going to be immune to the diseases that you diagnose and treat in others. This, coupled with the fact that I had a very young son, made my self-diagnosis doubly shocking. Of all the concerns about serious
health problems and a shortened life expectancy, however, the prospect of not seeing my two-year-old son grow into maturity was the thing that disturbed me most.
I had taken extra training in diabetes in my last year of family medicine residency and knew about the diabetic diet and how lifestyle change was supposed to be the cornerstone of diabetes management. I also knew that, for the most part, newly diagnosed type 2 diabetics went on drug therapy immediately because of the ineffectiveness of lifestyle interventions and that, even then, most tended to struggle and fail in their attempts to maintain normal blood glucose values. Further complicating my situation was the fact that I abhorred the use of medication.
Did the diabetes occur out of the blue?
Clearly, I’d been in denial. I’d put on some weight and was fatigued all the time. I struggled through bouts of afternoon drowsiness. I got up at night to urinate, was constantly thirsty, and needed to squint to see the television news. My blood pressure was also rising into the zone that would require treatment. I rationalized all these developing problems as the natural and inevitable effects of aging until it suddenly dawned on me that I had the typical symptoms of diabetes. I tested myself and confirmed that my blood sugar was way too high. In order to buy time while I looked at the recent science and formulated a management plan, I decided not to eat anything that would exacerbate my soaring blood sugar. I immediately stopped eating sugar and starchy foods, but at the time I didn’t have a clue about low-carb diets.
What was the result of your dietary shift?
Almost immediately, my blood sugar normalized, followed by a dramatic and steady loss of weight—about a pound a day. My other symptoms swiftly vanished, too. I started seeing clearly, the excessive urination and thirst disappeared, my energy level went up, and I began to feel immensely better. I bought an exercise bike and started riding it for thirty minutes every day as I continued to avoid starches and sugars. It was my wife who pointed out that I was on the Atkins Diet. She had struggled to lose weight after the birth of our son and had tried various diets. I recall that when she brought home an Atkins book I was dismissive, suggesting that it was just another of the fad diets and that it probably wouldn’t work over the long haul. As I read the book, I realized that I wasn’t actually following Dr. Atkins’s phased approach to carb restriction, I was simply avoiding all carbs.
How did your personal situation impact your practice?
As I began to realize that my simple dietary intervention was rapidly and effectively resolving my own diabetes, I naturally started to look at the broader aboriginal diabetes epidemic through this lens. In my travels to First Nations communities, I started to question people, especially the elders, about their traditional ways of eating. It was common, especially in coastal communities, to consume traditional foods like salmon, halibut, and shellfish. Inland, one would eat moose, deer, and elk. It was also common to eat modern fare, such as potato and pasta salads with the salmon and moose, cakes and cookies for dessert, all chased with juices and soda pop.
I began to understand that the traditional diet didn’t have a significant source of starch or sugar. People ate berries, but the vast majority of calories came in the form of protein and fat. A number of seasonal wild plants, akin to modern greens, were all low in starch and sugar. The traditional diet was looking very much like a modern-day lowcarb diet in terms of its macronutrient content.
How did you test your theory?
Around this time a medical journal published a study in which a group of overweight men were put on the Atkins Diet and followed it for six months. The men lost significant weight and experienced an improvement in their cholesterol levels. I suggested to my two community medicine specialists that we design a similar study for a cohort of First Nations subjects.
I had started speaking to First Nation audiences about my ideas of a link between their changing diet and the epidemics of obesity and diabetes. Ultimately, the Canadian government agreed to fund a trial study to look at the effects of a traditional low-carb diet on obesity and diabetes. I was also able to spend two years on research leave at the University of British Columbia Department of Health Care.
How is your health today?
For about seven years, I’ve adhered to the diet and continue to maintain normal blood sugar and blood pressure and a weight loss of about 25 pounds. After the first six months, I had my cholesterol checked. I’d become accustomed to eating lots of fatty foods, including my own wickedly delicious low-carb chocolate ice cream recipe. I have to admit I was afraid. I’d been taught that a diet high in saturated fat would lead to an unhealthy lipid profile. Much to my surprise and relief, I had excellent cholesterol. I was clearly on the right track.
My most recent blood tests continue to demonstrate excellent results. Although my total cholesterol and LDL cholesterol are above normal limits, I know from reading the scientific literature that this is not a concern given that the important markers for cardiovascular risk, HDL and triglycerides, are well within normal limits and my C-reactive protein is exceptionally low. With a pattern like this, although I have not tested for small, dense LDL, I can assume that my LDL is of the healthy variety. I am convinced that my health is better than it has ever been. I have learned an enormous amount in an area of science that physicians, unfortunately, tend to ignore: nutrition.
Has your research been published yet?
At this point, we’re collecting data. After statistical analysis, we’ll write the paper and submit it for publication in a scientific journal. Meanwhile, the study and how it affected the people of the Namgis First Nation and other residents of Alert Bay is the subject of the documentary My Big Fat Diet.
(For more information, see www.cbc.ca/thelens/bigfatdiet.)
Chapter 14 MANAGING DIABETES, AKA THE BULLY DISEASE
Diabetes now affects more than 18 million people in the United States alone, but because the early stages can be completely silent, as many as 8 million of them are unaware that they have the disease.
The Atkins Diet is more than just a healthy lifestyle. As you’ve learned in the previous chapter, this way of eating can significantly reduce your chances of developing heart disease and metabolic syndrome. Now you’ll learn that the Atkins Diet is also an extremely effective tool to manage diabetes. We’ve previously pointed out that dietary carbohydrates act like a metabolic bully, demanding that they be burned first and pushing fats to the back of the line, which promotes the buildup of excess fat stores. Just as an individual who has been bullied for years may stop fighting back, some people’s bodies eventually give in to the ongoing stress of too much sugar and other refined carbohydrates. The result is type 2 diabetes, which occurs when the body loses its ability to keep blood sugar within a safe range. When this happens, the swings in blood sugar—sometimes too low, but mostly too high—start to do their damage.
ONE NAME, TWO DISEASES
Though most people know that diabetes has something to do with insulin, they’re generally confused about exactly what that means. That’s not surprising, considering that two different conditions (type 1 diabetes and type 2 diabetes) share the name. Both types involve insulin, the hormone that facilitates the movement of glucose into cells to be burned or stored. Simply put, type 1 diabetes reflects a problem in insulin production that results in low insulin levels. Type 2, on the other hand, reflects a problem in insulin action (insulin resistance), which results in high insulin levels. Type 2 occurs mainly in adults and is the much more common form, representing 85 to 90 percent of all cases worldwide. Type 1 is more common in children, but thanks to the rapid increase in obesity among younger people, tragically this age group is also now developing type 2 diabetes.
If you’ve already been diagnosed with type 2 diabetes and have been testing your blood sugar after meals—or you live with someone who does—you’ve probably noticed that foods rich in carbohydrates drive blood sugar higher than those composed mostly of proteins and fats. If so, this chapter will confirm your suspicions
that a healthful diet should limit carbohydrates to an amount that doesn’t elevate blood sugar to the level that can inflict damage. And for the rest of us who don’t (yet) have diabetes, it will soon become apparent that the best way to prevent this illness is by reducing dietary carbs to the point where they no longer function as a metabolic bully.
A “SILENT” DISEASE … BUT AN ENORMOUS EPIDEMIC
About one-third of people with type 2 diabetes in the United States are unaware that they have this disease. Fortunately, diagnosing diabetes is as simple as checking a small amount of your blood for its blood sugar (glucose) level or your blood level of hemoglobin Alc (HbAlc), which indicates your blood glucose level over the last several months. Your health care provider can perform either of these tests at a routine checkup, and many employers provide workplace screening (see the sidebar “Understanding Blood Sugar Readings” for more on testing). Because diabetes is so common and checking for it is so easy, if you don’t know if you have diabetes, there’s no reason not to find out as soon as possible.