A new study shows that eating ultra-processed food can impact brain health and puts people at risk of developing early signs of Parkinson's disease.

The study, based on more than 20 years of data, revealed that eating large amounts of ultra-processed foods, 11 servings compared to three a day, can increase a person's risk of developing the neurodegenerative disorder.

Signs that could develop before someone experiences tremors include muscle stiffness, changes in handwriting and subtle changes in walking.

Scientists say the link between these foods and Parkinson's may be due to changes in the integrity of the brain.

This study is one of many that has highlighted the negative impact of eating ultra-processed foods. Previous studies showed links to heart disease, dementia and some types of cancer.

Doctors recommend people cook at home when possible and carefully read labels on packaged food.