People with Parkinson’s Disease may be consuming a diet high in sugar that is linked to impulse control disorders and chronic pain, Australian study suggests.

A survey of  103 Parkinson’s patients at Royal North Shore Hospital in Sydney revealed that they had greater total carbohydrate intake (279 g/day vs. 232 g/day, p = 0.034) than a healthy control group.

The high carbohydrate intake was largely due to increased daily sugar intake (153 g/day vs. 119 g/day, p = 0.003) and in particular free sugars (61 g/day vs. 41 g/day, p = 0.001), according tom researchers led by Dr  Natalie Palavra of the Department of Neurology.

Further analysis showed that increased sugar consumption was significantly associated with chronic pain, depressions, and patients reporting an impulse control disorder (all p < 0.05).

Increased sugar consumption was also associated with an increase in non-motor symptoms, including poorer quality of life, increased constipation severity and greater daily levodopa dose requirement.

The investigators said the nutrition survey findings revealed that Parkinson’s patients consumed an unhealthy diet, and the cohort had a mean BMI of 26. More than one in four patients (28%) had more than 10% of their energy intake attributed to free sugar, compared to 7.5% of healthy control group.

“There are several reasons why Parkinson’s Disease patients may consume more sugar. It has been suggested that carbohydrates and sweets, through insulin, may increase brain dopamine as somewhat of a compensatory mechanism for disease-related dopamine loss,” they wrote in Frontiers in Nutrition.

The association with impulse control disorder might be related to the high rates of eating disorders in people with Parkinson’s Disease, and the possibility that that the patients in the study were binge eating, they suggested.

The links between depression and pain and sugar intake may be related to the high rates of depression seen in people with Parkinson’s and a possible role for serotonin in eating behaviour, the researchers said.

Neurodegeneration of the serotonergic system, with low levels of serotonin in Parkinson’s Disease, may explain the pronounced preference for sweet foods,” they commented.

The association between sugar consumption and indicators of disease severity, such as more non-motor symptoms may suggest the possibility of comfort eating behaviour, they added.

“We provide clinically important insights into the dietary habits of Parkinson’s Disease patients that may inform simple dietary modifications that could alleviate disease symptoms and severity …  patients would benefit from dietitian input as part of routine clinical management,” they concluded.