Concerns over egg consumption and heart disease were shown to be misplaced some years ago, although a study published earlier this year has again raised questions. But what about egg consumption leading to a higher risk of stroke?
A small study from the University of Eastern Finland has shown that a moderately high intake of dietary cholesterol, or consumption of up to one egg per day, is not associated with an elevated risk of stroke.
Additionally, the study found no association in carriers of the APOE4 phenotype, common in the Finnish population, which affects cholesterol metabolism. The findings of this study are the first to be published looking at an association in this group.
Findings from earlier studies addressing the association of dietary cholesterol or egg intake with the risk of stroke have been contradictory. Some found an association between high dietary cholesterol intake and stroke risk, while others have associated consumption of eggs with reduced risk.
For most people, dietary cholesterol plays a very small role affecting their serum cholesterol levels. However, in carriers of the apoliproptein E phenotype 4 – which significantly impacts cholesterol metabolism – the effect of dietary cholesterol on serum cholesterol levels is greater. In Finland, the prevalence of APOE4 is exceptionally high, and found in approximately one third of the population.
At greater risk?
The dietary habits of 1,950 men aged 42-60 years with no baseline diagnosis of cardiovascular disease were assessed at the start of a heart disease study carried out in the 1980s at the University of Eastern Finland. APOE phenotype data were available for 1,105 of the participating men and, of them, 32 percent were known carriers of APOE4.
During a follow-up of 21 years, 217 men were diagnosed with stroke. The study found that neither cholesterol nor egg consumption was associated with the risk of stroke, including in carriers of APOE4.
The findings suggest that moderate cholesterol intake, or daily egg consumption, are not associated with the risk of stroke, even in persons who are genetically predisposed to a greater effect of dietary cholesterol on serum cholesterol levels.
In the highest control group, the study participants had an average daily dietary cholesterol intake of 520 mg and consumed an average of one egg per day, and the researchers note that the findings cannot be generalized beyond this level.
One egg contains approximately 200 mg of cholesterol. In this study, about a fourth of the dietary cholesterol consumed came from eggs.
The researchers note that the study population did not have pre-existing cardiovascular disease at baseline and that the size of study population was relatively small. They have called for the study’s findings to be verified in a larger cohort as well as in people with pre-existing cardiovascular disease, who are currently advised to limit their intake of cholesterol and eggs.