Thirty years ago, when Nathan Pritikin opened the Pritikin Longevity Center to help people improve cholesterol levels and prevent heart attacks, he noticed that many people at the Center were struggling not just with high cholesterol but also with hypertension and high blood sugar. Several had full-blown diabetes. Most were also overweight.
The good news, Nathan observed, was that his diet-and-exercise program seemed to help all these problems. But Nathan, ever curious about the workings of the human body, was perplexed. Why, he wondered, did all these things seem to go hand-in-hand? Could they be linked in some way?
Today, scientists have answers to Nathan’s observations. There is a link, and it’s called the Metabolic Syndrome.
What is the Metabolic Syndrome?
The Metabolic Syndrome, also known as Syndrome X, is not a disease, per se. Rather, it is a cluster of factors (see below) that are an important warning sign because the syndrome can lead to diabetes as well as heart disease. In the next decade, predicts Dr. David Heber, Director of UCLA’s Center for Human Nutrition, roughly 80% of all heart disease will be due to the Metabolic Syndrome and type 2 diabetes. Even if blood sugar levels never go high enough to be classified as diabetes, the Metabolic Syndrome still promotes heart disease.
According to guidelines established by the National Cholesterol Education Program, you probably have the Metabolic Syndrome if you have three or more of the following five risk factors:
- Abdominal obesity: a waist of 40 inches or more for men, 35 inches or more for women
- High triglycerides: 150 mg/dL or more
- Low HDL (“good”) cholesterol: below 40 mg/dL for men, below 50 for women. Most people with the syndrome also have more small, dense LDL (“very bad”) cholesterol particles*
- High blood pressure: 130/85 or higher (or if you are taking hypertension medication)
- Elevated fasting blood sugar (glucose): 110 mg/dL** or more
* These small, dense LDLs are usually not measured with standard blood lipid profiles. To monitor them, the physicians at the Pritikin Center order specialized blood tests.
** A few months ago, the American Diabetes Association lowered the cut point for elevated fasting glucose to 100 mg/dL, so the Pritikin Center uses 100 – not 110 – to denote elevated glucose.
If you have the Metabolic Syndrome, you’re far from alone. According to new government figures, more than 64 million Americans have it, roughly one in four adults and 40% of adults age 40 and older, an increase of 60% over the last decade.
Alarmingly, growing numbers of kids are now being diagnosed with the syndrome. Newly published research from Yale University found that the fatter the child, the more likely he or she is to have the syndrome, and those who are severely obese have a 50% chance of having it.(1)
What causes the Metabolic Syndrome?
The Metabolic Syndrome usually begins with insulin resistance. Insulin resistance happens when our cells “resist” insulin. Normally, our body changes the sugars and starches we eat into a form of sugar called glucose. The bloodstream carries the glucose to the body’s cells. Insulin, a hormone produced by the pancreas, “ushers” glucose into our cells, where it’s converted to energy. You are insulin resistant if your cells don’t want to “accept” the insulin. Figuratively-speaking, your cells have signs on their doors that say, “Sorry, closed for business. We already have all the glucose we need.” So the pancreas has to pump out more insulin in an effort to “push” those doors open and keep blood sugar levels from going too high.
In about half of all cases, insulin resistance leads to ever-rising blood sugar levels and type 2 diabetes (defined as fasting glucose of 126 mg/dL or more). That’s why insulin resistance is often called a “pre-diabetic” condition. Ultimately, the pancreas may give out. For years, it’s been on overdrive, pumping out more and more insulin, trying to break through the cells’ doors. Eventually, it cannot produce enough extra insulin to overcome the insulin resistance. That’s why people who’ve had type 2 diabetes for many years must often resort to insulin shots.
What causes insulin resistance?
Here’s what we know. Environment plays a key role: the great majority of people with insulin resistance are overweight. But scientists know genetic susceptibility plays a role as well because some normal-weight people are insulin resistant – and some very obese people are not.
Four other factors contribute to insulin resistance: poor diet, inactivity, smoking, and aging. Even in normal-weight people, a diet high in fats and refined sugars is associated with greater risk of developing insulin resistance and all other aspects of the Metabolic Syndrome.
How do you prevent or control the Metabolic Syndrome?
There is no one magic pill that erases the syndrome. Pharmaceutically, it is treated in piecemeal fashion. People take one type of drug, usually statins, to control cholesterol, another to lower blood pressure, another to lower triglycerides, and still others to treat high blood sugar. To date, no drugs have been approved for insulin resistance.
The far better approach – one that treats the overall problem – is the more natural way: a healthy diet and regular exercise. It is also the most effective way, argue experts like UCLA’s Dr. Heber and Dr. Paul Ridker of the Center for Cardiovascular Disease Prevention at Brigham and Women’s Hospital in Boston, because it targets what are often the roots of the problem: poor diet and excess body fat, especially in the belly.
Oh, what that spare tire can do
Excess abdominal fat is so problematic, scientists are now finding, because it is not just a dormant roll of flab. Those fat cells, wrapped around organs like the liver and pancreas, are very active. They pump out chemicals, like cytokines, that raise blood pressure, worsen cholesterol levels, and foul up the delicate system by which insulin works, causing insulin resistance. They also trigger inflammation throughout the body. That’s bad news because high levels of inflammation mean high levels of C-reactive protein (CPR), which are increasingly linked with higher risk of heart attacks, strokes, osteoarthritis, and even Alzheimer’s disease.
But when you start to lose body fat with lifestyle-change programs like Pritikin, all these problems fade – quickly and simultaneously. Since 1980, studies published in peer-reviewed journals like Diabetes Care and the New England Journal of Medicine have shown that the Pritikin Program lowers blood pressure, dramatically improves cholesterol and triglyceride profiles, sheds body fat, and normalizes blood sugar levels.
The good news, too, is that just a small amount of weight loss – about 5% of body weight – can help restore insulin sensitivity. In fact, just getting started on the Pritikin Program nets huge benefits. In only three weeks, UCLA researchers found, the Pritikin Program controlled the Metabolic Syndrome in a majority of 72 people studied. Insulin levels dropped an average of 32%, and triglycerides fell 26%. Average weight loss was 8.5 pounds; total cholesterol dropped 22%; and blood pressure returned to normal levels.(2)
Newly published research also found that in just two weeks C-reactive protein levels plummeted on average 45% in women at the Pritikin Longevity Center.(3) No other diet-and-exercise program or drug therapy, including statins, has proven to lower C-reactive protein so dramatically or rapidly.
And just last month, doctors and dietitians at Pritikin analyzed the data of 37 men and women, all with the Metabolic Syndrome, who came to Pritikin for two weeks. They found that 50% graduated from Pritikin free of the Metabolic Syndrome. They had improved their profiles – cholesterol, blood pressure, triglycerides, and blood sugars – so much that they no longer met the three-risk-factor criteria for the syndrome.
“The results of this study suggest that dramatic changes in diet and activity levels can quickly and favorably alter most of the metabolic abnormalities seen in people with the Metabolic Syndrome,” notes Dr. James Kenney, Nutrition Research Specialist at the Pritikin Longevity Center.
Children benefit, too. In a just completed analysis of kids attending the Pritikin Family Program last summer, UCLA scientists found that all eight of the children who came to Pritikin with the Metabolic Syndrome left Pritikin just two weeks later free of the syndrome.
Some low-carb diet books claim that a high-carbohydrate diet causes insulin resistance, and that in turn is what’s making us fat. Such claims are bogus. “There’s no evidence that carbohydrate-rich foods cause insulin resistance,” summarized the Berkeley Wellness Letter in June 2003. “Moreover, insulin resistance doesn’t make people fat. Most experts believe that insulin resistance is largely a result of obesity, lack of exercise, smoking, and aging.”
Key cause of obesity
People get fat because they take in more calories than they burn. Plain and simple. A diet that is dense with calories and a lifestyle with little or no calorie-burning physical activity promote excess calorie intake, excess weight, insulin resistance, and associated metabolic problems.
The optimal dietary approach
The vast majority of nutrition scientists agree that the best way to control weight is to control calories, and the best way to control calories – without going hungry – is to eat foods that provide a lot of stomach-filling volume, but not a lot of calories. This is a diet, in effect, that is full of fiber- and water-rich foods like fruits, vegetables, beans, and whole grains. The second requirement: daily exercise.
The evidence in support of fiber-rich, water-rich foods to control weight is so strong that in its Report of the U.S. Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2005, the 13-member panel of experts from academia recommended that overweight Americans choose foods that allow them to eat larger portions for fewer calories – foods, in short, that have a low calorie density, such as “raw vegetables or low-fat soups.” The experts advised that Americans choose whole grains over refined grains, and increase their intake of fruits and vegetables to 5 to 13 servings daily.
Potatoes vs. croissants
In general, fat-rich foods and more processed and refined foods are more calorie-dense than foods in their natural whole state. Calorie for calorie, they also provide far less satisfaction, or satiety. Research analyzing how full people felt after eating 100 calories of various foods found that some of the least filling foods were cakes, doughnuts, and cookies (all high in fat, sugar, and refined carbs).(4) Per calorie, it would take over six times the amount of calories from croissants to achieve the same level of satiety as baked potatoes.
The more croissants and other calorie-dense foods you eat, the more calories you are likely to ingest, and the greater your risk of becoming insulin resistant. In animals genetically susceptible to insulin resistance, research has shown that simply offering them a diet high in fat and refined carbohydrate leads to overeating and induction of insulin resistance within just a few days.(5)
And in large-scale population studies of men and women in the U.S., Harvard researchers found that diets with more hydrogenated and saturated fat were linked with the development of insulin resistance and the Metabolic Syndrome. Conversely, diets higher in unrefined carbohydrates appeared protective.(6, 7)
Diets focusing on fiber-filled, unrefined carbohydrates have also been proven to prevent diabetes. Results from two long-term trials studying nearly 4,000 people with a pre-diabetic condition called impaired glucose tolerance – the U.S. Diabetes Prevention Program (8) and the Finnish Diabetes Prevention Group (9) – found that diets high in fruits, vegetables, beans, and whole grains combined with exercise led to weight loss and about a 60% reduced risk of developing diabetes.
And new research from Oregon Health & Science University found that a low-fat, high-fiber diet caused significant weight loss in type 2 diabetics, whereas a diet high in monounsaturated fats did not.
For both diets, the subjects were encouraged to eat ad libitum, that is, as much or as little as they wanted. This “real world” approach, the scientists suspected, would create more accurate results than previous studies, which had forced subjects to eat as many calories on low-fat diets as they had on high-fat diets. Unlike these earlier studies, the low-fat, ad libitum diet in the Oregon study did not raise triglyceride levels or worsen glycemic control. In fact, it improved both. The authors concluded that “ad libitum low-fat, high-fiber diets may be very useful in the dietary management of type 2 diabetes.” (10)
And recently, the U.S. Agriculture Research Service found that eating more whole-grain foods eased the Metabolic Syndrome. The scientists, from Tufts University in Boston, analyzed food consumption data and medical tests from 2,834 men and women and concluded that eating three or more servings of whole-grain foods like fiber-rich cereals and brown rice each day improved insulin sensitivity and lowered the risk of Metabolic Syndrome. Refined grains did not protect against the syndrome.(11)
The optimal approach for preventing the Metabolic Syndrome is to lose excess weight with regular exercise and a diet, like the Pritikin Eating Plan, that focuses on foods that are low in calorie density and naturally high in fiber and nutrients, including whole-grain foods like hot cereals, corn, whole-wheat pasta, and brown rice; generous amounts of fruits, vegetables, and starchy foods like potatoes, yams, beans, lentils, and peas; and modest amounts of nonfat dairy products, seafood, and lean poultry and meat.
As more than 100 studies in top medical journals have proven, and as Nathan Pritikin observed nearly 30 years ago, this simple but powerful diet-and-exercise approach acts like a one-two punch on the Metabolic Syndrome, and, in doing so, helps prevent and control the leading causes of death and disability in the United States, including cardiovascular disease, type 2 diabetes, hypertension, and stroke.“If ever there were a magic bullet for losing weight and building long-term health, the Pritikin Program is it,” sums up Dr. Kenney.
(1) New England Journal of Medicine, 2004; 350: 2362.
(2) American Journal of Cardiology, 1992; 69: 440.
(3) Metabolism, 2004; 53: 377.
(4) European Journal of Clinical Nutrition, 1995; 49: 675.
(5) Diabetes, 2001; 50: 2786.
(6) American Journal of Clinical Nutrition, 2001; 73: 1019.
(7) Diabetes Care, 2002; 25: 417.
(8) New England Journal of Medicine, 2002; 346: 393.
(9) New England Journal of Medicine, 2001; 344: 1343.
(10) American Journal of Clinical Nutrition, 2004; 80: 668.
(11) Diabetes Care, 2004; 27: 538.