title: Macronutrients intake and risk of Parkinson's disease: A meta-analysis.
abstract: OBJECTIVE
  We carried out a meta-analysis to summarize the evidence from published studies on macronutrients intake and risk of Parkinson's disease (PD).
  
  
  METHODS
  Pertinent studies were identified by a search of PubMed and Embase. Study-specific effect was combined with the random-effect model. The dose-response relationship was assessed by the restricted cubic spline.
  
  
  RESULTS
  For highest versus lowest level of intake, the relative risk (RR) of PD was 1.13 (95% CI 0.88-1.44) for protein (7 articles including 1570 PD cases among 357,827 subjects), RR 1.24 (95% CI 1.05-1.48) for carbohydrate (8 articles including 1482 PD cases among 232,869 subjects), RR 0.88 (95% CI 0.74-1.06) for fat (12 articles including 2936 PD cases among 374,124 subjects), RR 0.97 (95% CI 0.75-1.26) for cholesterol (6 articles including 1713 PD cases among 170,058 subjects) and 1.39 (95% CI 1.01-1.92) for energy (8 articles including 1553 PD cases among 170,317 subjects), respectively. Among prospective studies adjusting for smoking and coffee/caffeine, no associations were found between PD risk and intake of protein (RR 1.02, 95% CI 0.80-1.30), carbohydrate (RR 1.11, 95% CI 0.86-1.43), fat (RR 0.90, 95% CI 0.70-1.16), cholesterol (RR 0.89, 95% CI 0.74-1.09) and energy (RR 0.97, 95% CI 0.93-1.02); however, polyunsaturated fatty acid (RR 0.78, 95% CI 0.64-0.96) was inversely associated with PD risk. Limited data showed a linear dose-response relationship between the aforementioned macronutrients and PD risk.
  
  
  CONCLUSIONS
  Dietary intake of protein, carbohydrate, cholesterol and energy might be not independently associated with PD risk. Higher intake of polyunsaturated fatty acid might be inversely associated with PD risk. Confounding by smoking and coffee/caffeine should be considered regarding the association between fat intake and PD risk in further studies.
authors.affiliation: Department of Nursing, Qingdao University Medical College, Qingdao, China.
authors.forename: Aimin
authors.initials: A
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Lin
authors.forename: Yili
authors.initials: Y
authors.lastname: Wu
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Zhang
mesh_terms: D000368:Aged; D002791:Cholesterol, Dietary / Q000009:adverse effects; D004040:Dietary Carbohydrates / Q000009:adverse effects; D004044:Dietary Proteins / Q000009:adverse effects; D002149:Energy Intake; D005231:Fatty Acids, Unsaturated / Q000009:adverse effects; D006801:Humans; D010300:Parkinson Disease / Q000453:epidemiology / Q000209:etiology*; D018570:Risk Assessment
chemical_list: D002791:Cholesterol, Dietary; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D005231:Fatty Acids, Unsaturated
keywords: Parkinson's disease; macronutrients; meta-analysis