Year: 2014
Type: dissertation
Study design: Observational Study
Abstract: As more individuals survive into advanced age, prevention of dementia and cognitive impairments is of increasing public health importance.The aetiology of dementia and Alzheimer's disease (AD) -a major cause of dementia -is considered to be multifactorial, resulting from both genetic and environmental factors.The present thesis aimed at obtaining a comprehensive understanding of the role of diet in the development of dementia/AD and cognitive impairment.The working hypothesis was that a healthy diet at midlife would reduce the risk of dementia/AD and cognitive impairment later in life.The present thesis was based on the Finnish Cardiovascular Risk Factors, Aging and Incidence of Dementia (CAIDE) project.CAIDE is a population-based study investigating cardiovascular and lifestyle-related risk factors for dementia.The participants (n=2000) were derived from independent population-based random samples (North Karelia Project, FINMONICA study) studied in 1972, 1977, 1982 or 1987 (midlife/baseline examination), when they were on average 50 years old (range 39-64 years).During the midlife examination, dietary information was collected.Re-examination of the cohort was carried out in 1998 in two geographically defined areas in Eastern Finland (in Kuopio and Joensuu), and altogether 1449 people (73%) aged 65-79 years participated.This series of studies showed that an abundant saturated fat (SFA) intake from milk products and spreads at midlife was associated with poorer global cognitive functioning and prospective memory and with an increased risk of mild cognitive impairment (MCI).A high intake of polyunsaturated fatty acids (PUFAs) was associated with better semantic memory.Fish consumption tended to be related to better global cognitive functioning and semantic memory, and higher PUFA-SFA ratio to better performance in psychomotor speed and executive functioning.In addition, a moderate intake of unsaturated fats from spreads at midlife was protective, whereas a moderate intake of SFAs increased the risk of dementia and AD, especially among individuals carrying the apolipoprotein E (ApoE) ε4 allele.The participants who drank moderate amounts of coffee (3-5 cups/day) at midlife had the lowest risk of dementia/AD later in life compared to individuals drinking less/not at all.For tea drinking, no association was found.Furthermore, the effect of healthy diet on dementia risk was examined with a healthy-diet index; this was constructed including both healthy and unhealthy dietary components.Adherence to a healthy diet at midlife was associated with a decreased risk of dementia/AD in late-life.In summary, these results emphasize that unhealthy dietary factors at midlife may increase the risk of developing dementia/AD later in life and have a negative effect on several cognitive domains, whereas healthier dietary choices may act in the reverse manner.The current data suggests that healthy dietary choices at midlife may increase the possibility for brain health later in life.
Author: Marjo H. Eskelinen
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: green
Awards: G2719705196, G3858951504, G8948019489
OpenAlex ID: W3096650874