Living Low Carb (13 page)

But there’s a problem.

What happened to the 50% of the people
between
those two extremes? It turns out they had neither the terrific glucose metabolism of the top 25% nor the full-blown insulin resistance of the bottom 25%; instead, they fell somewhere in between. One could easily argue that since only 25% of the population had flawless glucose metabolism, the rest of us—up to 75% of the population—have
some
degree of insulin resistance! Remember, too, that Reaven used young, healthy adults as subjects, and their numbers are definitely not representative of the population as a whole—the fact is, insulin sensitivity actually decreases as you get older. The take-home point: insulin resistance isn’t just something that happens to other people. Recently, the American Association of Clinical Endocrinologists estimated that one in three Americans is insulin-resistant.
²⁶

D
IABETES AND
C
OMPLICATIONS

•  
80 percent of diabetics are insulin-resistant.

•  
2,200 people are newly diagnosed each day.

•  
Diabetes is the seventh leading cause of death in the United States.

•  
60–70 percent of diabetics have mild to severe forms of nerve damage.

•  
Diabetes is the leading cause of lower-extremity amputations in the United States.

•  
86,000 amputations a year are related to complications from diabetes.

•  
The five-year mortality rate after amputation is 39–68 percent.

•  
Diabetics are two to four times more likely to have heart disease.

•  
Heart disease is present in 75 percent of diabetes-related deaths.

•  
Diabetes is the leading cause of new cases of kidney disease.

•  
Diabetes is the leading cause of new cases of blindness in adults.

•  
Each year, 12,000–24,000 people lose their sight because of diabetes.

Source: American Podiatric Medical Association, American Diabetes Association, CDC, American Association of Diabetes Educators, and National Diabetes Educational Program

There are approximately 17 million diabetics in the United States, of which 5.9 million are not yet diagnosed.
²⁷
Approximately 80% of them are insulin-resistant. Even if you are insulin-resistant and somehow manage to dodge the diabetes bullet, you are still at serious risk for heart disease. Being overweight (having a body mass index of greater than 25 or a waistline of greater than 40 inches for men, 35 inches for women) is a risk factor for insulin resistance—a big one. So are hypertension (high blood pressure), elevated triglycerides, and low-HDL cholesterol.
²⁸
It’s estimated that 47 million Americans have some combination of these risk factors.
²⁹
As you have seen in this chapter, all of them are related to insulin, and
virtually all of them improve substantially on a low-carbohydrate diet
.

How a Low-Carb Diet May Help Prevent—or Even Reverse—Diabetes

Dietary treatment for diabetes is currently one of the hottest topics of debate in the diabetes community.
³⁰
Some factions are passionately holding on to the old recommendations of a high-carb diet, while other clinicians are making strenuous arguments for lower-carb, higher-fat, higher-protein diets.
³¹
The precise dietary treatment for full-blown type 2 diabetes is beyond the scope of this book, though it is a fascinating subject and in my opinion has great relevance for nondiabetics as well. What can we say for sure? A number of studies have shown that people on low-carbohydrate diets experience increased glucose control, reduced insulin resistance, weight reduction, lowered triglycerides, and improved cholesterol.

Excess Insulin and PCOS

One in ten women has polycystic ovary syndrome (PCOS), the most common reproductive abnormality in premenopausal women, which puts them at high risk for both cardiovascular disease and diabetes.
³²
One of the major biochemical features of PCOS is the combination of insulin resistance and hyperinsulinemia (elevated insulin levels). The ability of obese women with PCOS to use glucose is significantly impaired, and they have a marked reduction in insulin sensitivity.
³³

When we talk about insulin resistance, we often forget that not all tissues and cells become resistant at the same time, and some do not become resistant at all. For example, overweight people may—at least in the beginning—have very nonresistant fat cells. Their muscle cells refuse to take any more sugar, but the fat cells still have open arms. These cells are said to be insulin-sensitive. The ovaries also tend to remain insulin-sensitive. If there’s a genetic predisposition for these glands to overproduce androgen hormones—as there is with women who have PCOS—the excess insulin that’s sent into the bloodstream to deal with the excess sugar bathes these nonresistant tissues in an ocean of insulin that is way too much for their needs. One of the responses to all that insulin hitting the ovaries is that they produce even more testosterone and androstene, which leads to hair loss, acne, obesity, infertility, and other symptoms of PCOS.

L
OW
-G
LYCEMIC
D
IET AND
D
IABETES

Low-glycemic foods—beans, peas, lentils, pasta, rice boiled briefly, and breads like pumpernickel and flaxseed—do a better job of managing glycemic control for type 2 diabetes and risk factors for coronary heart disease than diets based around the “traditional” high-fiber foods such as whole-grain breads, crackers, and breakfast cereals.

That’s the finding of a 2008 study published in the
Journal of the American Medical Association
.
^*

Although the American Dietetic Association continues to mindlessly parrot the “conventional” wisdom about whole-grain breads and cereals, the truth is that most of these whole-grain products are fiber lightweights. (Read the label—whole grains typically offer 1–2 grams of fiber at best, compared to 11–17 in a cup of beans.) And if you check the glycemic index/glycemic load tables, you find that the difference between a processed grain like white rice and its whole-grain counterpart (brown rice) is—from a
blood-sugar
point of view—almost negligible.

Obviously, whole grains are better than white junk, but only because they contain slightly more vitamins and other nutrients. From a bloodsugar—and from a food-sensitivity or allergy—standpoint, they’re not that much of an improvement. If you’ve got a gluten sensitivity—which is way more common than you might think—whole grains will be just as much a problem for you as the processed kind.

In the
JAMA
study, researchers found that hemoglobin A1c—a very important marker for diabetes—decreased
significantly
more in subjects on the low-glycemic diet than it did for people eating the “traditional high-fiber” choices with cereal fiber. The low-glycemic group also saw a significant increase in HDL (the so-called “good” cholesterol) as well as a significant reduction in LDL (the so-called “bad” cholesterol).

The low-glycemic diet group did eat some breads—like pumpernickel, rye pita, and quinoa bread with flaxseed—and some cereals—like real oatmeal—but they were all low-glycemic.

Bottom line: just because a cereal or bread product says “made with whole grains” doesn’t mean it’s the best food for you. Many of these products raise your blood sugar to a level that is way too high, and manufacturers are notorious at trading on the “whole grain” buzz to create ridiculous products like “whole grain Cocoa Captain Sugar Krispies” (I made that one up, but you get the point).

Glycemic impact is very important and should be paid attention to by anyone interested in his or her health. And you don’t have to walk around with a bunch of scientific formulas to figure out whether a food has high or low glycemic impact: just look for foods that have minimal processing, maximum color (the exception is oatmeal and cauliflower), and as much fiber as possible.

^*
David J. Jenkins, Cyril W. Kendall, Gail McKeown-Eyssen, et al., “Effect of a lowglycemic index or a high-cereal fiber diet on type 2 diabetes,”
Journal of the American Medical Association
300 (2008): 2742–2753.

Interestingly, those affected with PCOS often have relatives with adultonset diabetes, obesity, elevated triglycerides, and high blood pressure.
³⁴
Sound familiar? This is why a low-carb diet is the dietary treatment of choice for PCOS. It’s a common enough problem that many of the community bulletin boards on the low-carb sites listed in the Resources section have specific areas for PCOS.

Excess Insulin and Inflammation

Essential fatty acids, notably members of the omega-6 and omega-3 family, are the parent molecules for an entirely different group of fascinating hormones called eicosanoids. Eicosanoids, formerly called prostaglandins, live in the body for only seconds and act on the cells that are in their immediate vicinity—they don’t travel in the bloodstream. They are very, very powerful modulators of human health. Like many other systems in the body, they need to be in balance. Sometimes, as a shorthand, we’ll talk about “good” eicosanoids (the prostaglandin 1 series, or PG1), which inhibit clotting, promote vasodilation, stimulate the immune response, and are anti-inflammatory, versus the “bad” eicosanoids (the prostaglandin 2 series, or PG2), which have the opposite effects, promoting clotting, constriction, and inflammation. But this shorthand is not completely accurate, as you need a
balance
of the two. For example, if you clotted too much and too easily, you could have a stroke; but if you didn’t clot at all, you’d bleed to death from a hemorrhage!

Here, too, insulin leaves its mighty footprint. Insulin inhibits a critical enzyme called delta-6-desaturase, which is responsible for directing traffic into the production line for the “good,” anti-inflammatory eicosanoids. Inflammation has been implicated in a host of conditions, from heart disease to Alzheimer’s to arthritis to food allergies. In fact, the modulation of insulin for the purpose of controlling eicosanoid production and reducing the risk of heart disease was the major reason for the development of the Zone diet by Barry Sears. If you’re interested in learning more about this diet, be sure to read about it in
chapter 7
.

Excess Insulin and Aging

“If there is a single marker for life span,” asserts Dr. Ron Rosedale, author of
The Rosedale Diet
, “it’s insulin sensitivity.”
³⁵
He’s right. In 1992, researchers collected data on people who were both mentally and physically fit and were at least a hundred years old. The researchers looked carefully to find the factors these folks might have in common, the ones that could be predictors for a long and healthy life. They came up with three. The first was low triglycerides. The second was high-HDL cholesterol. Can you guess the third? A low level of fasting insulin!
³⁶
You’ve learned in this chapter how a lower-carbohydrate diet almost always improves all three of these variables. Since this kind of diet is what our ancestors ate for eons, it makes sense that we would live the longest and stay the healthiest by adhering to it.

By the way, the only dietary strategy shown to actually
increase
life span in laboratory animals has been calorie restriction. When we humans try calorie restriction on a standard high-carb, low-fat diet, we generally hate it—we’re hungry all the time. With a diet higher in protein, higher in fat, and lower in carbohydrates—and high in fiber—we’re more satiated and our appetite is much more under control. Insulin—the hunger hormone—is no longer out of control, blood sugar is manageable, and weight becomes stabilized. We can actually wind up eating fewer calories and feeling more satisfied in the bargain. That’s a recipe for an anti-aging, health-producing diet
without
creating cravings or hunger pangs.

Switching to a Fat-Burning Metabolism: The Meaning of Ketosis

When you go on a low-carbohydrate diet, you restrict the amount of sugar coming into your system. That’s a good thing. But what
happens
when there’s a severely reduced amount of sugar coming down the pike? What does the body use for fuel?

S
ENIOR
M
OMENT
?
M
AYBE
I
T’S
Y
OUR
B
LOOD
S
UGAR
!

Is the phrase “I’m having one of those senior moments” becoming an increasingly common utterance?

New research suggests that it might be related to your sugar levels.