Abstract
Previous studies have suggested a link between flavonoid intake and better cognitive function in later life but have not been able to control for possible confounding by prior intelligence quotient (IQ). The aim of the present study was to address this issue in a cross-sectional survey of 1091 men and women born in 1936, in whom IQ was measured at age 11 years. At the age of 70 years, participants carried out various neuropsychological tests and completed a FFQ. Associations between test scores and nutrient intake were assessed by linear regression with adjustment for potentially confounding variables. Total fruit, citrus fruits, apple and tea intakes were initially found to be associated with better scores in a variety of cognitive tests, but the associations were no longer statistically significant after adjusting for confounding factors, including childhood IQ. Flavanone intake was initially found to be associated with better scores in verbal fluency (P = 0·003, with standardised regression coefficient 0·10), but, again, the association was no longer statistically significant after adjusting for confounding factors. These findings do not support a role for flavonoids in the prevention of cognitive decline in later life. Studies of diet and cognitive function should include measurement of potential confounding variables, including prior IQ wherever possible.
| Original language | English |
|---|---|
| Pages (from-to) | 141-148 |
| Number of pages | 8 |
| Journal | British Journal of Nutrition |
| Volume | 106 |
| Issue number | 1 |
| Early online date | 8 Feb 2011 |
| DOIs | |
| Publication status | Published - Jul 2011 |
Bibliographical note
The authors' contributions are as follows: C. B. performed the statistical analysis and data interpretation, and was involved in the writing and editing of the manuscript; J. K. and G. M. performed the statistical analysis, data interpretation, revisions to the manuscript and approval of the final version; J. C. and A. G. had a role in data collection, checking and management, revising the manuscript and approval of the final version; J. M. S. co-designed the statistical analysis models, revised the manuscript and approved the final version; I. J. D. designed the study, directed the study, trained and validated cognitive testing, co-designed the statistical analysis models, revised the manuscript and approved the final version. J. C. and A. J. G. are funded by the Sidney De Haan Award, part of the Disconnected Mind project funding from Help The Aged to I. J. D. and J. M. S. In addition, a Research Into Ageing programme grant to I. J. D. and J. M. S. also supported A. J. G. and J. C. Further funding was obtained from an SpR Start-up Grant from the British Geriatrics Society to C. B. We thank the Scottish Council for Research in Education for allowing access to the SMS1947. The present study was undertaken by the University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology, part of the cross-council Lifelong Health and Wellbeing Initiative. Funding from the BBSRC, EPSRC, ESRC and MRC is gratefully acknowledged. We thank the Lothian Birth Cohort 1936 study participants. We also acknowledge Lorna Aucott, Statistician from the University of Aberdeen, for her help with the statistical analysis. The authors declare that there are no conflicts of interest.Keywords
- cognition
- elderly
- flavonoids