Diets for Syndrome X: Which carb is best?

Opinions vary on approaches to insulin resistance

The epidemic of obesity in America and the consequent avalanche of diets, fad diets, information, and disinformation may be bogging patients into a quagmire of uncertainty. With weight loss a major consideration for a high proportion of patients with Type 2 diabetes, they are asking questions such as: "High-carb? Low-carb? Zone? Atkins?"

How to answer?

Almost universally the answer comes back: Approach weight loss with sense and reason.

"The success formula for weight loss is so individualized that there is no one-size-fits-all cookie-cutter plan," says Sheila Kelly, MS, RD, LD, CDE, clinical nutrition manager at Providence Hospital in Washington, DC.

Syndrome X, a cluster of changes that encourages the onset of diabetes and heart disease, has been a medically accepted condition since Stanford endocrine researcher Gerald Reaven, MD, first used the term a dozen years ago. But the complex compilation of factors leading up to insulin resistance and subsequent cardiovascular risks has been acknowledged for 50 years or more.

Two sides of the same coin

From insulin resistance to diabetes is only a very short leap, says Reaven, an endocrinologist and professor of medicine at Stanford University in Palo Alto, CA.

"The difference between the two is artificial. In both situations, a patient cannot put out enough insulin to keep blood glucose from going up. It’s two sides of the same coin," says Reaven, author of Syndrome X: Overcoming the Silent Killer That Can Give You a Heart Attack.

Routine tests and physical examinations reveal Syndrome X (see above chart), which is characterized by elevated fasting blood glucose, elevated triglycerides, low HDL cholesterol, being overweight, elevated blood pressure, sedentary lifestyle, and a family history of heart disease, hypertension, or diabetes.

Compare the Makeup of Popular Diets:
Diet Protein Saturated Fat Mono- and Poly-unsaturated Fat Carbohydrate Cholesterol
American Heart Association 15% 5-10% 20% 55-60% 300 mg/day
Syndrome X 15% 5-10% 30-35% 45% 300 mg/day
Zone Diet* 30% 6% 24% 40% 210 mg/day
Atkins* 22% 25% 35% 18% 880 mg/day
*Those diets make no specific recommendations; proportions were calculated from recommended menu plans.
Source: Gerald Reaven, MD. Syndrome X: Overcoming the Silent Killer that Can Give You a Heart Attack, New York City: Simon & Schuster; 2000.

Reaven’s hypothesis: Eating up to 45% of calories in dietary fat will actually help overcome insulin resistance, as long as the vast proportion of those fats (30%-35% of daily caloric intake) comes from poly- and monounsaturated fats like olive oil, soft margarine, nonfat milk products, nuts, poultry, and fish.(See chart, above.)

He also disagrees with the American Heart Association’s recommendation that a healthy diet contains 55% to 60% of calories from carbohydrates — at least for people with Syndrome X and diabetes. Instead, he recommends much lower carbohydrate consumption at about 45% of total caloric intake.

New book complicates matters

Then there are the more extreme diets, like the much-criticized Atkins Diet, which encourages high protein and high fat intake of all types with very low carbohydrate consumption. And there’s the somewhat more moderate Zone diet.

To further complicate matters, a recently published book, Syndrome X: The Complete Nutritional Program to Prevent and Reverse Insulin Resistance, by Burton Berkson, MD, PhD, a cellular biologist and president of Integrative Medical Centers of New Mexico in Las Cruces, recommends a relatively high protein and low carbohydrate diet for Syndrome X.

"It’s a steady diet of refined carbohydrates that causes Syndrome X," theorizes Berkson, so he recommends what has been called a Paleolithic diet — one rich in animal protein and a wide variety of unprocessed grains, fruits, and nuts, much like our distant ancestors might have consumed.

That still doesn’t give us a clear picture of what diet is best for patients with diabetes or impaired glucose tolerance. And, unfortunately, the answer to that question isn’t going to make a clinician’s job any easier.

"Each patient is individual, so we have to devise an individual plan for each patient," says Kelly. "It depends on the individual’s unique metabolism and on what that person is willing to do, so generic approaches just don’t work."

She recommends against extremes, like the Atkins Diet, which she calls "incredibly dangerous in terms of dangers of kidney failure and bone loss" because of its high animal fat and subsequent high cholesterol content. "I tried the Atkins Diet myself for a paper I was writing, and fell off it after five days," Kelly says. "There’s no way you can support a modicum of physical activity on that diet, and we all know how important exercise is to managing diabetes."

Kelly recommends starting on a 55-20-30 ratio of carbohydrates to proteins to fats "and then take it from there — see what works, how well the patient adheres to the diet, and make whatever adjustments need to be made."

Kelly’s clincher, which seems to keep refined carbohydrate intake in check: Her recommended diet includes 35 grams of fiber a day to control blood glucose absorption and prevent cholesterol synthesis. "If they get that, by default they won’t be able to get their carbs from cakes or candy or even white bread," she says.

Columbia University associate research scientist Wahida Karmally, MS, RD, CDE, agrees with Kelly — to a point. "One description doesn’t fit all, but some come close to it," she says.

And to Karmally’s thinking Reaven’s Syndrome X diet is a model for moderation. It comes closest to providing what patients with diabetes need, Karmally says.

"Nobody has shown scientifically that high-protein diets increase satiety and thereby reduce caloric intake," she says. "And we don’t know the effect of high protein on kidneys, but certainly it makes them work harder."

This could present unique problems for patients with diabetes who are at risk of renal disease, she says.

In addition, Karmally says, low carbing excludes consumption of whole grains that have well-documented benefits, including prevention of heart disease and certain types of cancers. "For diabetics, I have to do it with each patient," she explains. "I work with them and look at blood sugar levels, postprandial glucose, whether they’re on insulin or oral meds, and then we look at it together. That’s the key. I can give them diets forever, but it’s useless if they won’t stick to them."

Movement key to prevention

The American Diabetic Association falls more into the Reaven camp in its dietary recommendations, according to Marion Parrott, MD, the Arlington, VA-based ADA’s vice president for clinical affairs.

"We eat too many calories and we’re too inactive," says Parrott. "We could just as easily call diabetes an inactivity disease."

Parrott says anything that improves energy levels and keeps people moving will help prevent and control diabetes, although she doesn’t recommend high-protein, high-fat, or high-carbohydrate diets because of possible nutritional shortcomings and stress on other organs.

"The Syndrome X diet is not off the wall, not at all. And it might be helpful for people with certain lipid abnormalities that make up the syndrome," Parrott concludes.

Another prominent nutrition researcher also falls firmly on the side of Reaven’s Syndrome X diet and just as strongly against the diets like Berkson’s and Atkins’.

"The Berkson diet is essentially the Atkins Diet, which is bad for the heart and kidneys," says Victor Herbert, MD, professor of medicine at the Mount Sinai School of Medicine in New York and director of hematology and nutrition research at the Bronx Veterans Affairs Medical Center.

[Contact Gerald Reaven at (650) 266-7450, Burton Berkson at (505) 526-8320, Sheila Kelly at (202) 269-7000, Wahida Karmally at (212) 305-6639 and Marion Parrott at (703) 549-1500.]