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)

Abstract

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.

Dietary Trends and Dementia - A Multi-Country Ecological Analysis

“…The data in this study did not differentiate between types of meat or preparation methods, so it is possible that the protective effects of some meats and the detrimental effects of others counterbalanced each other to produce an insignificant finding. The insignificant findings of this study are unable to provide support for or against meat, but rather echo calls for further research to disentangle the complex relationship that different types of protein sources and preparation methods may have with dementia incidence (Ylilauri et al ., 2022)…”

“…Despite the appeal of a dietary strategy for reducing dementia incidence, research has yielded mixed results. Although prevailing dietary wisdom (Quan et al ., 2022) indicates that lowering meat consumption may be beneficial for dementia outcomes, this is not universally accepted with Ylilauri et al ., (2022) finding that there is no association between animal product consumption and dementia. Other studies have found protective effects of egg (Lee et al ., 2021), whole milk (Muñoz-Garach et al , 2021), and meat consumption (Ngabirano et al ., 2019).…”

Association of dietary meat consumption habits with neurodegenerative cognitive impairment: an updated systematic review and dose–response meta-analysis of 24 prospective cohort studies

“…When we conducted a dose–response analysis of meat intake and the risk of NCI, five studies provided detailed data for ≥3 categories. 14,16,29,32,37 With the use of a restricted cubic splines model, we observed evidence of a linear association between fish and poultry intake and the risk of adverse cognitive outcomes ( p < 0.001; Fig. 6A and B).…”

“…Studies have considered that saturated fat and total cholesterol are risk factors for cardiovascular disease in relation to an increased risk of cognitive disorders. 14,29 However, adjusting those variables did not attenuate the association between meat consumption and cognitive disorders, which indicated that saturated fat and total cholesterol were not mediating factors. 15 Furthermore, in this study, the associations may be different if processed and unprocessed meats are studied separately; the consumption of unprocessed, lean meat may be favorable, whereas the consumption of processed meat is unfavorable; however, the findings are inconsistent.…”

“…The key characteristics of each included study are presented in Table 1. Thirteen studies were conducted in European countries (e.g., France, 7,[22][23][24][25] the UK, 14 Germany, 26 Greece, 11,27,28 and Finland 29 ), and four studies were conducted in the US. 2,[30][31][32] The remaining studies were conducted in China, 5,33,34 Australia, 35 Singapore, 16 Brazil, 36 and Japan.…”