Summary: A new study reports there appears to be no link between a high intake of dietary cholesterol and an increased risk of dementia, even in those who carried the APOE4 gene.
Source: University of Eastern Finland.
A new study from the University of Eastern Finland shows that a relatively high intake of dietary cholesterol, or eating one egg every day, are not associated with an elevated risk of dementia or Alzheimer’s disease. Furthermore, no association was found in persons carrying the APOE4 gene variant that affects cholesterol metabolism and increases the risk of memory disorders. APOE4 is common in Finland. The findings were published in the American Journal of Clinical Nutrition.
High serum cholesterol levels have been linked not only to an increased risk of cardiovascular diseases, but also to an increased risk of memory disorders. In the majority of the population, dietary cholesterol affects serum cholesterol levels only slightly, and many nutrition recommendations worldwide no longer set limitations on the intake of dietary cholesterol. In carriers of APOE4, however, the effect of dietary cholesterol on serum cholesterol levels is more visible. In Finland, the prevalence of APOE4, which is a hereditary variant, is exceptionally high and approximately one third of the population are carriers. APOE4 is a risk factor of both cardiovascular diseases and memory disorders. However, research data on the association between a high intake of dietary cholesterol and the risk of memory disorders in this population group hasn’t been available until now.
The dietary habits of 2,497 men aged between 42 and 60 years and with no baseline diagnosis of a memory disorder were assessed at the onset the Kuopio Ischaemic Heart Disease Risk Factor Study, KIHD, in 1984-1989 at the University of Eastern Finland. During a follow-up of 22 years, 337 men were diagnosed with a memory disorder, 266 of them with Alzheimer’s disease. 32.5 per cent of the study participants were carriers of APOE4.
The study found that a high intake of dietary cholesterol was not associated with the risk of dementia or Alzheimer’s disease – not in the entire study population nor in the carriers of APOE4. Moreover, the consumption of eggs, which are a significant source of dietary cholesterol, was not associated with the risk of dementia or Alzheimer’s disease. On the contrary, the consumption of eggs was associated with better results in certain tests measuring cognitive performance.
The findings suggest that a high-cholesterol diet or frequent consumption of eggs do not increase the risk of memory disorders even in persons who are genetically predisposed to a greater effect of dietary cholesterol on serum cholesterol levels than others. In the highest control group, the study participants had an average daily dietary cholesterol intake of 520 mg and they consumed an average of one egg per day, which means that the findings cannot be generalised beyond these levels.
Source: Jyrki Virtanen – University of Eastern Finland
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Original Research: Abstract for “Association of dietary cholesterol and egg intakes with the risk of incident dementia or Alzheimer disease: the Kuopio Ischaemic Heart Disease Risk Factor Study” by Maija PT Ylilauri, Sari Voutilainen, Eija Lönnroos, Jaakko Mursu, Heli EK Virtanen, Timo T Koskinen, Jukka T Salonen, Tomi-Pekka Tuomainen, and Jyrki K Virtanen in American Journal of Clinical Nutrition. Published online January 4 2017 doi:10.3945/ajcn.116.146753
Risk factors for eating disorder symptoms at 12 years of age: A 6-year longitudinal cohort study
Background: There is little information about the associations of intakes of cholesterol and eggs, a major source of dietary cholesterol, with the risk of cognitive decline in general populations or in carriers of apolipoprotein E ɛ4 (APO-E4), a major risk factor for dementia.
Objective: We investigated the associations of cholesterol and egg intakes with incident dementia, Alzheimer disease (AD), and cognitive performance in middle-aged and older men from Eastern Finland.
Design: A total of 2497 dementia-free men, aged 42–60 y in 1984–1989 at the baseline examinations of the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study, were included in the study. Information on the apolipoprotein E (Apo-E) phenotype was available for 1259 men. Data on cognitive performance tests at the 4-y re-examinations were available for 480 men. Dietary intakes were assessed with the use of 4-d food records at baseline. Dementia and AD diagnoses were based on Finnish health registers. Cox regression and ANCOVA were used for the analyses.
Results: During the 21.9-y follow-up, 337 men were diagnosed with dementia, and 266 men were diagnosed with AD. Neither cholesterol nor egg intake was associated with a higher risk of incident dementia or AD. For example, when evaluated continuously, each intake of 100 mg cholesterol/d was associated with a multivariable-adjusted HR of 0.9 (95% CI: 0.79, 1.02) for incident dementia, and each additional 0.5 egg (27 g)/d was associated with an HR of 0.89 (95% CI: 0.78, 1.01). However, egg intake was associated with better performance on neuropsychological tests of the frontal lobe and executive functioning, the Trail Making Test, and the Verbal Fluency Test. The Apo-E4 phenotype did not modify the associations of cholesterol or egg intake (P-interactions > 0.11).
Conclusions: Neither cholesterol nor egg intake is associated with an increased risk of incident dementia or AD in Eastern Finnish men. Instead, moderate egg intake may have a beneficial association with certain areas of cognitive performance.
“Association of dietary cholesterol and egg intakes with the risk of incident dementia or Alzheimer disease: the Kuopio Ischaemic Heart Disease Risk Factor Study” by Maija PT Ylilauri, Sari Voutilainen, Eija Lönnroos, Jaakko Mursu, Heli EK Virtanen, Timo T Koskinen, Jukka T Salonen, Tomi-Pekka Tuomainen, and Jyrki K Virtanen in American Journal of Clinical Nutrition. Published online January 4 2017 doi:10.3945/ajcn.116.146753