July 20, 2004
by Kylene Kiang
For people who have diabetes, high-protein and low-carbohydrate diets such as the Atkins diet should be used with caution, health experts advise.
The risks are twofold. Not only does protein overload stress the kidneys, but also the severe decrease in carbohydrate intake can lead to dangerously low blood-sugar levels, which may induce diabetic coma.
Research shows high-protein diets often contribute to an enlargement of the kidneys, said Marcia Silver, assistant professor of medicine at the Case Western Reserve University School of Medicine.
“The unusually large size of the kidney is an indication that the kidney is working harder than it normally should,” Silver said. “Kidneys that are pushed to function more early in life are prone to failure.”
Because people with diabetes are often predisposed to kidney disease, the health risks from high-protein dieting intensifies, said Maryellen Eichman-Fiala, a dietitian in the Diabetes Self-Management Education Program at LakeWest Hospital in Willoughby.
According to the Atkins Nutritional Web site, kidney dysfunction will occur during the diet only if “someone is already suffering from far-advanced kidney disease.” The site maintains that protein has nothing to do with the cause of the kidney problem.
Low-carb diets are based on the idea that if carbohydrate intake is limited, the body will use its own fat as a main source of energy. When the body feeds on its fat stores, byproducts known as ketone bodies form and induce a state called ketosis.
Ketosis is the same state typical for people who are fasting or experiencing extreme starvation.
For some people on low-carb diets, in addition to the rapid loss of fat, muscle tissue decreases, and for some, heart tissue can be lost, Eichman-Fiala said.
“The last I looked, no one needs to lose that,” she said.
The Atkins diet does not allow fruit, bread, pasta, grains, nuts, milk and starchy vegetables to be eaten during the first two weeks of the program, which can reduce carbohydrates to as low as 10 percent of what dietitians recommend. After this induction phase, more foods with carbohydrates are slowly reintroduced into the diet.
Nancy Dame, a registered dietitian at Cuyahoga Falls General Hospital, said her main concern with mixing low-carb diets and diabetes is the likelihood of dangerously low blood-sugar levels during the first two weeks of the diet.
People with diabetes who allow their blood sugars to drop to severely low levels may pass out, develop tremors or go into a diabetic coma, Dame said.
Because many food groups are missing from the induction phase, Atkins guidelines recommend taking vitamin supplements.
But Dame said taking pills is never the same as eating actual food.
“You might be getting vitamin A and vitamin C, but it’s not going to replace things like fiber and other phytonutrients.”
For people managing diabetes, Eichman-Fiala suggests limiting carbohydrates rather than eliminating them. Although she does not recommend the Atkins diet for people with diabetes, she said a positive effect of the low-carb craze is the greater recognition that overloading on carbohydrates is unhealthy.
But when choosing a diet, people should keep in mind that long-term health benefits are uncertain for many low-carb plans, she said.
“Whether it’s the ice cream diet or the alcoholic’s diet … all of those diets can work in the short run,” she said.