Ketone diet could help in Parkinson's.

Long before the low-carb diet became a weight-loss fad, doctors used a stricter version of it to treat people with epilepsy. Now, researchers are tailoring that therapy to fight Parkinson's disease.

Fats account for 90 percent of the new diet's calories, whereas carbohydrates make up only 2 percent. That ratio forces the body to produce fat-derived molecules, called ketones, that then serve as a substitute fuel for the carbohydrate-starved brain. Researchers suspect that ketones might ward off brain disorders that stem from malfunctions in how cells use carbohydrates (SN: 12/13/03, p. 376).

Compliance with the diet is a problem, however. Many people reject the mayonnaise-, butter-, and oil-rich regimen as unpalatable, or they experience worrisome surges in cholesterol.

To reduce the cholesterol effect, Columbia University professor emeritus Theodore B. VanItallie and his colleagues designed a ketone-generating diet rich in unsaturated fats, including canola and olive oils. Unlike saturated fats, these fats tend to improve a person's cholesterol profile.

The researchers instructed five Parkinson's patients to follow the plan for 28 days. The volunteers, ages 46 to 74, were all overweight and lived at home during the study. Four were female.

Only three patients stuck closely to the diet. Even so, by the study's end, all five showed improvements in their Parkinson's symptoms, which had included poor muscle control and depressed mood. Only one patient had a large jump in her cholesterol concentration, the researchers report in the Feb. 22 Neurology.

VanItallie cautions that a placebo effect could explain the improvements, but he says the results are encouraging.

"People with Parkinson's, or at least some of them, were able to prepare this diet at home and stay on it for 4 weeks," without harmful cholesterol effects, he says.--B.H.