Dietary intake and olfactory function in patients with newly diagnosed Parkinson's disease: a case-control study

Objective: To evaluate energy and nutrient intake in newly diagnosed Parkinson's disease (PD) patients and association between olfaction and nutrient density of the diet. Design: Baseline data from a prospective cohort study. Subjects: Eighty-seven patients and 28 age-and sex-matched controls participated in the study. Methods: Dietary intake was assessed by using 3-day dietary records and 24-hour dietary recalls. The Brief Smell Identification Test (B-SIT) was used to test olfaction. Results: Patients, compared with controls, had lower intake of polyunsaturated fatty acids (P = 0.024) and a higher intake of carbohydrates (P = 0.027) in energy percent (E%). Lower intake of protein (E%) (P = 0.045), and a low nutrient density of folate (P = 0.022), magnesium (P = 0.012), and phosphorus (P = 0.029) were associated with lower B-SIT score in both patients and controls. PD patients had a lower B-SIT score than controls (P < 0.001). Conclusion: The results indicate a higher relative contribution of energy from carbohydrates in PD patients. An association between low protein, folate, magnesium, and phosphorus density of the diet and olfaction was seen in the whole population.