Let’s End the Week on a Good Note

A year ago I summarized a study from Kaiser Permanente data that showed raised total cholesterol levels in middle age predicted the occurrence of Alzheimer’s in a ‘dose-dependent’ fashion.  Now there’s a larger study from Johns Hopkins, published in the journal Neurology, that says it isn’t so!

For the study, 1,462 women in Sweden between 38 and 60 were followed for 32 years.  They were dementia-free at enrollment; at this time they had a physical exam, a full cardiovascular exam, chest X-ray and blood tests.  Their lifestyle (smoking, alcohol and medication use), education level, and medical history were recorded.  Body mass index (BMI) and blood pressure were measured throughout the study.  Tests for dementia were conducted at 4 intervals during the study.  Those women who were 70 or older at the final exam had all analyses repeated.

After 32 years, 161 women (11%) had developed dementia.   Higher blood total cholesterol levels at enrollment were not associated with an increased risk of dementia.  On the other hand, a time-dependent decrease in cholesterol over the follow-up period was associated with an increased risk of dementia.  Thus the risk increased from 8.9% for those maintaining or increasing their cholesterol over the course of the study to 17.5% for those with the greatest decline in cholesterol!

This study is bound to cause some head scratching among experts, and the debate will probably rage until more studies are completed and reported out.  In the meantime, a raised cholesterol remains important; levels should be monitored and treated through diet, exercise, and medication if necessary.