title: Turmeric improves post-prandial working memory in pre-diabetes independent of insulin.
abstract: OBJECTIVE
  Cognitive impairment develops with pre-diabetes and dementia is a complication of diabetes. Natural products like turmeric and cinnamon may ameliorate the underlying pathogenesis.
  
  
  METHODS
  People ≥ 60 years (n=48) with newly-recognised untreated pre-diabetes were randomised to a double-blind metabolic study of placebo, turmeric (1 g), cinnamon (2 g) or both (1 g & 2 g respectively), ingested at a white bread (119 g) breakfast. Observations were made over 6 hours for pre- and post-working memory (WM), glycaemic and insulin responses and biomarkers of Alzheimer's disease (AD)(0, 2, 4 and 6 hours): amyloid precursor protein (APP), γ-secretase subunits presenilin-1 (PS1), presenilin-2 (PS2), and glycogen synthase kinase (GSK-3β). Differences between natural product users and non-users were determined by Students t and chi square tests; and between pre-test and post-test WM by Wilcoxon signed rank tests. Interaction between turmeric and cinnamon was tested by 2-way ANOVA. Multivariable linear regression (MLR) took account of BMI, glycaemia, insulin and AD biomarkers in the WM responses to turmeric and cinnamon.
  
  
  RESULTS
  No interaction between turmeric and cinnamon was detected. WM increased from 2.6 to 2.9 out of 3.0 (p=0.05) with turmeric, but was unchanged with cinnamon. WM improvement was inversely associated with insulin resistance (r=-0.418, p<0.01), but not with AD biomarkers. With MLR, the WM responses to turmeric were best predicted with an R2 of 34.5%; and with significant turmeric, BMI and insulin/glucose AUC beta-coefficients.
  
  
  CONCLUSIONS
  Co-ingestion of turmeric with white bread increases working memory independent of body fatness, glycaemia, insulin, or AD biomarkers.
authors.affiliation: Fuli institute of Food Science and Nutrition, Room D437 Agriculture Biological and Environmental Buliding, Zijingang Campus, Zhejiang University, 833 Yuhantang, West Lake District, Hang-zhou City, Zhejiang Province, China 310058; Division of Population Health Sciences, NHRI, Zhunan, Miaoli, Taiwan 35053. mark.wahlqvist@gmail.com.
authors.forename: Meei-Shyuan
authors.initials: MS
authors.lastname: Lee
authors.forename: Mark L
authors.initials: ML
authors.lastname: Wahlqvist
authors.forename: Yu-Ching
authors.initials: YC
authors.lastname: Chou
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Fang
authors.forename: Jiunn-Tay
authors.initials: JT
authors.lastname: Lee
authors.forename: Jen-Chun
authors.initials: JC
authors.lastname: Kuan
authors.forename: Hsiao-Yu
authors.initials: HY
authors.lastname: Liu
authors.forename: Ting-Mei
authors.initials: TM
authors.lastname: Lu
authors.forename: Lili
authors.initials: L
authors.lastname: Xiu
authors.forename: Chih-Cheng
authors.initials: CC
authors.lastname: Hsu
authors.forename: Zane B
authors.initials: ZB
authors.lastname: Andrews
authors.forename: Wen-Harn
authors.initials: WH
authors.lastname: Pan
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D001939:Bread; D002935:Cinnamomum zeylanicum; D030024:Curcuma; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008568:Memory / Q000187:drug effects*; D008875:Middle Aged; D008517:Phytotherapy; D010919:Placebos; D028321:Plant Preparations / Q000008:administration & dosage / Q000627:therapeutic use*; D019518:Postprandial Period; D011236:Prediabetic State / Q000097:blood / Q000150:complications*
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D010919:Placebos; D028321:Plant Preparations