Can a healthy diet reduce the risk of Parkinson’s?

While movement problems are the main symptoms of Parkinson’s disease, people with the disease often have non-motor symptoms such as constipation, sleeping during the day and depression 10 or more years before the movement problems begin. A new study suggests that eating a healthy diet in middle age may be linked to having fewer of these preceding symptoms. The study will be published in the August 19, 2020, online issue of Neurology.

“While this study shows no cause and effect, it certainly offers yet another reason to include more vegetables, nuts and legumes in your diet,” said study author Samantha Molsberry, Ph.D., of Harvard University in Boston, Mass. . “More research is needed to determine whether eating a healthy diet can slow or even prevent the development of Parkinson’s disease among people who already have these pre-existing symptoms.”

The study involved 47,679 people who were asked about their diet every four years in the early 1980s when they were in middle age. Then in 2012, people were asked if they had two conditions that are common in people who are later diagnosed with Parkinson’s disease: constipation and a sleep disorder called rapid onset sleep behavior disorder, which includes dreams performed during sleep by exercise such as fluttering arms as crying as crying. In 2014-2015, 17,400 participants were asked about five more symptoms that can precede Parkinson’s disease: loss of smoking, limited color vision, excessive sleeping during the day, body aches, and depression.

The researchers looked at how closely the diets of people follow the alternative Mediterranean diet, which is similar to the Mediterranean diet but includes only whole grains and does not include dairy, as the Alternative Healthy Eating Index. Both diets encourage the eating of fruits, vegetables, whole grains, nuts and legumes and discourage the eating of red meat. They divided the participants into five groups based on how closely they followed the diets.

The study found that the people with the highest adherence to the diet were less likely to have three or more symptoms that precede Parkinson’s disease than the people with the lowest attachment. Those in the high group for adherence to the Mediterranean diet were 33% less likely to have three or more symptoms than those in the group with low adherence. These results were found after researchers adjusted for other factors that may influence the risk of developing these pre-existing symptoms, such as physical activity, smoking and body mass index (BMI). The researchers found a similarly strong relationship between following the Alternative Healthy Eating Index diet pattern and having three or more of these non-motor symptoms.

Among the 29,899 women in the study, 37% of the low attachment group had constipation, compared with 32% of the high attachment group. Among the 11,493 women with all non-motor symptoms measured, 15% of the low group had body pain, compared with 13% of the high group. In the same 11,493 women, 17% of the low group had symptoms of depression, compared to 14% of the high group. Among the 17,770 men in the study, 22% in the low-attachment group had replacement, compared with 12% in the high-attachment group. Among the 5,907 men with data on all non-motor symptoms, 14% of the low group and 16% had body pain and 13% of the low group and 12% of the high group had symptoms of depression. Molsberry notes that body pain and depression may have occurred at a higher rate in the study than in the general population due to the design of the study, but that this was also taken into account in the statistical analysis.

Looking at individual diet groups, the researchers found that eating more vegetables, nuts, legumes and a moderate amount of alcohol consumed were all associated with a lower risk of having three or more of the previous symptoms. Moderate alcohol consumption was considered to be no more than one drink per day for women and no more than two drinks per day for men.

“We must emphasize that, although these symptoms are associated with an increased risk of Parkinson’s disease, especially in combination, experiencing one or more of these symptoms does not necessarily mean that a person will eventually develop Parkinson’s disease,” said Molsberry.

One limitation of the study was that participants at the start of the study were not asked about prior symptoms, so some people may already have these symptoms, which could have affected their diet.