Updated

Eating a Mediterranean-style diet rich in vegetables, grain, and fruit may reduce the risk of Parkinson's disease, a new study shows.

Researchers found people who ate a diet high in unsaturated fats were more than 30 percent less likely to develop Parkinson's disease. Unsaturated fats (mono and polyunsaturated fats) are two types of fats that can replace saturated fats in the diet. They are found in diets rich in vegetables, grain, fruit, and in vegetable oils including plant oils and nuts.

Parkinson's disease is a progressive neurological disorder caused by a loss of brain cells that produce the chemical dopamine. The loss of these cells leads to uncontrollable tremors and loss of smooth controlled muscle movements.

Approximately 1 million Americans have Parkinson's disease, including three out of every 100 people over the age of 60.

Read WebMD's "Intense Physical Activity Cuts Parkinson's Risk"

Fatty Acids May Protect Brain

The study, which appears in the current issue of Neurology, examined the relationship between fats in the diet and the risk of Parkinson's disease. At the study's start, a group of more than 5,500 men and women over age 55 were free of the disease. By the end of the study, about six years later, 51 participants developed Parkinson's disease.

The results showed that people who had diets highest in monounsaturated and polyunsaturated fats were 32 percent and 34 percent, respectively, less likely to develop Parkinson's disease.

Researchers say more studies are needed to confirm these results, but prior studies show that there are a few potential explanations for the protective effect against Parkinson's disease.

For example, although the exact cause of Parkinson's disease is unknown, inflammation and cellular damage are thought to play a role. Previous research has shown that polyunsaturated fatty acids have anti-inflammatory properties and nerve protective effects, and monounsaturated fatty acids reduce free radical damage to cells.

Read WebMD's "Omega-3 Fatty Acids Get New Health Claim"

By Jennifer Warner, reviewed by Brunilda Nazario, MD

SOURCE: de Lau, L. Neurology, June 2005; vol 64: pp 240-245