Associations of dairy, meat, and fish intakes with risk of incident dementia and with cognitive performance: the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD).

PURPOSE: To investigate if dairy, meat, and fish intakes associate with dementia and cognitive performance. METHODS: We included 2497 dementia-free men from Eastern Finland, aged 42-60 years in 1984-1989 at the baseline examinations. Data on cognitive tests [Mini Mental State Exam (MMSE), trail making test (TMT), verbal fluency test (VFL), selective reminding test (SRT), and Russell's adaptation of the visual reproduction test (VRT)] at the 4-year re-examinations were available for 482 men and on the ApoE phenotype for 1259 men. Data on dementia events were obtained by linkage to national health registers. Diet was assessed with baseline 4-day food records. Cox regression and analysis of covariance were used for analyses. RESULTS: During a mean 22-year follow-up, 337 men had a dementia diagnosis. Among the foods, only cheese intake associated with dementia risk (hazard ratio in the highest vs. the lowest quartile = 0.72, 95% confidence interval = 0.52-0.99, P-trend = 0.05). In the cognitive tests, higher non-fermented dairy and milk intakes associated with worse verbal fluency (VFT). Higher processed red meat intake associated with worse verbal (SRT) and visual memory (VRT), whereas higher unprocessed red meat intake associated with better general cognitive functioning (MMSE) and processing speed and executive functioning (TMT). Higher fish intake associated with better verbal memory (SRT). Among APOE-ε4 carriers, especially non-fermented dairy intake associated with higher risk of dementia outcomes, and higher fish intake indicated better cognitive performance. CONCLUSION: Although higher intake of some food groups associated with cognitive performance, we found little evidence for associations with dementia risk.

Associations of dietary choline intake with risk of incident dementia and with cognitive performance: the Kuopio Ischaemic Heart Disease Risk Factor Study.

BACKGROUND: Moderate egg intake has been associated with better cognitive performance in observational studies. This association may be due to the rich content of choline, especially phosphatidylcholine, in eggs because choline has been suggested to have a role in the prevention of cognitive decline. OBJECTIVES: We investigated the associations of dietary choline intake with the risk of incident dementia and with cognitive performance in middle-aged and older men in the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study. METHODS: A population-based sample of 2497 dementia-free men aged 42-60 y was examined in 1984-1989. A subset of 482 men completed 5 different cognitive performance tests 4 y later. Dementia and Alzheimer disease diagnoses were retrieved from Finnish health registers. Dietary intakes were assessed with the use of 4-d food records at baseline. Cox regression and ANCOVA were used for the analyses. All analyses were also stratified by the apolipoprotein E phenotype (APOE-ε4 compared with other phenotypes). These data were available for 1259 men. RESULTS: The mean ± SD total choline intake was 431 ± 88 mg/d, of which 188 ± 63 mg/d was phosphatidylcholine. During a 21.9-y follow-up, 337 men were diagnosed with dementia. Those in the highest compared with the lowest phosphatidylcholine intake quartile had 28% (95% CI: 1%, 48%; P-trend = 0.02 across quartiles) lower multivariable-adjusted risk of incident dementia. Total choline intake had no association with the risk of incident dementia. However, both total choline and phosphatidylcholine intakes were associated with better performance in cognitive tests assessing frontal and temporal lobe functioning. For example, higher intakes were associated with better performance in verbal fluency and memory functions. The APOE phenotype had little or no impact on the associations. CONCLUSION: Higher phosphatidylcholine intake was associated with lower risk of incident dementia and better cognitive performance in men in eastern Finland. This trial was registered at clinicaltrials.gov as NCT03221127.

Dietary proteins and protein sources and risk of death: the Kuopio Ischaemic Heart Disease Risk Factor Study.

BACKGROUND: Previous studies investigating protein intake in relation to mortality have provided conflicting results. OBJECTIVE: We investigated the associations of dietary protein and protein sources with risk of disease death in the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study. METHODS: The study population consisted of 2641 Finnish men, aged 42-60 y at baseline in 1984-1989. We estimated protein intakes with 4-d dietary records at baseline and collected data on disease deaths from the national Causes of Death Register. Cox proportional hazards regression models were used to estimate HRs and 95% CIs. RESULTS: During the average follow-up of 22.3 y, we observed 1225 deaths due to disease. Higher intakes of total protein and animal protein had borderline statistically significant associations with increased mortality risk: multivariable-adjusted HR (95% CI) in the highest compared with the lowest quartile for total protein intake = 1.17 (0.99, 1.39; P-trend across quartiles = 0.07) and for animal protein intake = 1.13 (0.95, 1.35; P-trend = 0.04). Higher animal-to-plant protein ratio (extreme-quartile HR = 1.23; 95% CI: 1.02, 1.49; P-trend = 0.01) and higher meat intake (extreme-quartile HR = 1.23; 95% CI: 1.04, 1.47; P-trend = 0.01) were associated with increased mortality. When evaluated based on disease history at baseline, the association of total protein with mortality appeared more evident among those with a history of type 2 diabetes, cardiovascular disease, or cancer (n = 1094) compared with those without disease history (n = 1547) (P-interaction = 0.05 or 0.07, depending on the model). Intakes of fish, eggs, dairy, or plant protein sources were not associated with mortality. CONCLUSIONS: Higher ratio of animal to plant protein in diet and higher meat intake were associated with increased mortality risk. Higher total protein intake appeared to be associated with mortality mainly among those with a predisposing disease. This trial was registered at clinicaltrials.gov as NCT03221127.