A moderate intake of dietary cholesterol or consumption of up to one egg daily is not connected with an elevated risk of stroke, according to a new study from the University of Eastern Finland. Also, the research found no link in carriers of the APOE4 phenotype, which affects cholesterol metabolism and is remarkably common among the Finnish population. The researchers published the findings of the study in the American Journal of Clinical Nutrition.

In earlier studies, there were contradictions on the association of dietary cholesterol or egg intake with the risk of stroke. Some research discovered a connection between high dietary cholesterol intake and an increased risk of stroke, while others have linked the consumption of eggs, which are high in cholesterol, with a reduced risk of stroke.

Dietary cholesterol, for most people, plays quite a small role in affection their serum cholesterol levels. However, in carriers of the apolipoprotein E phenotype 4, which significantly impacts cholesterol metabolism, the effect of dietary cholesterol on serum cholesterol levels is more considerate.

The prevalent of APOE4 in Finland, which is a genetic variant, is exceptionally high with approximately one-third of the population presenting as carriers. Even with that, research data on the connection between a high intake of dietary cholesterol and the risk of stroke in this population group has not been available until now.

The study assessed the dietary habits of 1,950 men aged between 42 and 60 years with no baseline diagnosis of cardiovascular disease at the onset the Kuopio Ischaemic Heart Disease Risk Factor Study, KIHS, in 1984 to 1989 at the University of Eastern Finland. APOE phenotype data were available for 1,015 of the men participating in the study. Of those, 32 percent were known carriers of APOE4.

In the course of a follow-up of 21 years, 217 men were diagnosed with a stroke. The study found that neither dietary cholesterol nor egg consumption was associated with the risk of stroke, not even in carriers of APOE4.

The outcomes of the study suggest moderate cholesterol intake or daily egg consumption are not connected with the risk of stroke, even in persons who are genetically predisposed to a more significant consequence of dietary cholesterol on serum cholesterol levels.

In the highest control group, the participants in the study had a regular daily dietary cholesterol intake of 520mg, and they consumed an average of one egg per day which means that the findings cannot be generalized beyond these levels.

In the study, approximately a fourth of the total dietary cholesterol consumed came from eggs. Also, there is a weakness in the generality of this study by the fact that the study population did not have a pre-existing cardiovascular disease at baseline, and the size of the study population was relatively small. Consequently, the findings of the study should be verified in a larger cohort as well as in people with a pre-existing cardiovascular disease who are currently advised to limit their intake of cholesterol and eggs.