JOENSUU, Finland, Jan. 9 (UPI) -- Researchers at the University of Eastern Finland have found no link between high cholesterol intake and an increased risk of dementia or Alzheimer's disease.
The study also found there was no association in people who carry the APOE4 gene variant that affects cholesterol metabolism and increases the risk of memory disorders.
A relatively high intake of dietary cholesterol is the equivalent of eating one egg per day. Dietary cholesterol affects serum cholesterol levels only slightly in the majority of the population and there are no longer set limitations on the intake of dietary cholesterol.
Serum cholesterol consists of high-density lipoprotein, or HDL, low-density lipoprotein, or LDL, and triglycerides.
High serum cholesterol levels have been associated with an increased risk of cardiovascular diseases along with memory disorders.
In carriers of APOE4, dietary cholesterol has a visible effect on serum cholesterol levels. Finland has a high prevalence of APOE4 with roughly one-third of the population being carriers.
For the study, researchers examined the dietary habits of 2,497 men ages 42 to 60 with no diagnosis of memory disorders. The men were assessed on the Kuopio Ischaemic Heart Disease Risk Factor Study, or KIHD, in 1984 to 1989 at the University of Eastern Finland.
Over a 22-year follow-up period, 337 men were diagnosed with memory disorder with 266 being diagnosed with Alzheimer's disease. Roughly 32.5 percent of the participants were APOE4 carriers.
The research found that a high intake of dietary cholesterol was not linked with a risk of dementia or Alzheimer's disease for the entire study population or the carriers of APOE4.
Additionally, the consumption of eggs was not associated with the risk of dementia or Alzheimer's disease, but was associated with better results in certain tests of cognitive performance.
The study was published in the American Journal of Clinical Nutrition.