Regularly consuming ultra-processed food not only can increase the chances of developing cancer or cardiovascular disease, as numerous studies have shown. This habit could also advance the early signs of Parkinson's disease, as indicated by a new study published in the journal Neurology.
"Maintaining a healthy diet is crucial and has been associated with a lower risk of developing neurodegenerative diseases. The food choices we make today can significantly influence our brain health in the future," stated Xiang Gao, a researcher at Fudan University in Shanghai (China) and leader of the study, emphasizing that "there is increasing evidence that diet may play a role in the development of Parkinson's disease. Our research shows that consuming a lot of processed food, such as sugary drinks and snacks, can accelerate the early signs of Parkinson's disease."
Gao's team followed a sample of 42,853 people with an average age of 48 years at the start of the study for 26 years who did not have Parkinson's disease when the study began.
Among other variables, the scientists analyzed the appearance of prodromal symptoms of the disease, early signs of the disorder that can occur years or even decades before the more characteristic symptoms of neurodegeneration begin, such as tremors, balance problems, or slow movements. Early signs include alterations such as loss of smell, sleep disorders, constipation, or apathy.
Additionally, they also conducted periodic check-ups on the participants, who also had to complete questionnaires about their well-being or habits, including a collection of their usual dietary choices.
With this data in hand, the researchers estimated how many ultra-processed products each participant consumed on average per day, considering categories such as sweets, sauces, snacks, sugary drinks, dairy desserts, sausages, etc.
Then, they divided the sample into five groups. In the group most fond of ultra-processed foods, participants consumed at least 11 servings of ultra-processed food per day. In the group with the lowest consumption, members ate less than three servings of ultra-processed foods per day.
After accounting for factors such as age, physical activity, or smoking status, the researchers found that participants who consumed 11 or more servings of ultra-processed foods per day had a 2.5 times higher risk of presenting three or more early signs of Parkinson's disease than those who consumed less than three servings of these products per day.
"Choosing to consume less processed food and more whole, nutritious foods could be a good strategy to maintain good brain health," stated Gao. The researcher noted that their work does not establish a causal relationship between consuming this type of food and the neurodegenerative disease and calls for further studies to confirm their findings.
An important limitation of their work, they acknowledge, is that the consumption of ultra-processed food was measured through self-completed questionnaires by the participants, which could introduce biases in the data recording.
Evidence of the health risks is extensive. The latest research on this topic, published last week in the journal American Journal of Preventive Medicine, showed that for every 10% of ultra-processed foods included in the daily diet, we add a 3% higher risk of mortality.
"Assessing deaths from all causes associated with their intake allows for a comprehensive estimation of the effect of industrial food processing on health," stated Eduardo Augusto Fernandes Nilson, from the Oswaldo Cruz Foundation (Fiocruz, Brazil), the lead author of the study, who highlighted that the percentage of preventable premature deaths from all causes by choosing ultra-processed foods can vary from 4% in countries with lower consumption to almost 14% in those with higher intake.
"This new study, following a very solid scientific methodology, provides new evidence to consider that what we eat today will have consequences for our mental health tomorrow," commented SMC Spain's Maira Bes-Rastrollo, professor of Preventive Medicine and Public Health at the University of Navarra, co-coordinator of the working group of the Spanish Society of Epidemiology, and member of CIBERobn.
"Analyzing the non-motor prodromal signs of Parkinson's disease is an advantage, as these appear ten or twenty years before the clinical diagnosis, providing an opportunity for early interventions to prevent the development of Parkinson's disease. However, it would be desirable to have other studies that also observe a relationship between the consumption of ultra-processed foods and the incidence of a Parkinson's disease diagnosis, not only with the early non-motor signs of the disease," added the researcher, who emphasized that "in any case, these results continue to support the need to discourage the consumption of ultra-processed foods, not only due to their increased risk with metabolic diseases but also with mental illnesses and the need to continue promoting the Mediterranean diet in the population, based on minimally processed foods with a high consumption of fruits, vegetables, legumes, whole grains, fish, and olive oil."