A decline in total cholesterol levels precedes the diagnosis of dementia by at least 15 years, according to an epidemiologic study reported in the Archives of Neurology.
This same statement came from Henry Lorin in his new book, "Alzheimer's Solved". Alzheimer's is rare in one with normal cholesterol.
"Studies like this are extremely valuable because they can provide a window into processes going on early in dementia, allowing researchers to look back in time at people's health and other characteristics and compare these between people who develop dementia and those who do not," Dr. Robert Stewart from King's College London, UK reported to Reuters.
Dr. Stewart and colleagues used data from the Honolulu-Asia Aging Study to compare the natural history of cholesterol level change over a 26-year period between 56 men who were found to have dementia at examination 3 years after the last cholesterol measurement and 971 men who did not have dementia.
Total cholesterol levels at the beginning of the study did not differ by later dementia status, the authors report, but the decline in subsequent cholesterol levels was significantly steeper among men who went on to develop dementia.
Adjustment for potential confounding factors strengthened the association between cholesterol level decline and the development of dementia, the results indicate.
The cholesterol level decline was most marked in men with dementia who also carried the APOE epsilon-4 gene, a marker currently undergoing considerable research, the researchers note.
"The observed associations may not represent direct causal pathways," the investigators say. "Hypocholesterolemia is recognized to be associated with frailty and poor general health. It also has been found to be specifically associated with inflammatory markers and poor nutritional status." This is particularly interesting in view of the presumed association of inflammatory markers with increased cardiovascular risk. Why so many practicing physicians are still focused on cholesterol elevation is a mystery to me.
Rather, they suggest, "It is possible that the decline in cholesterol levels is a marker for early processes that reflect neurodegenerative changes and also lead to a decline in general health status."
The drop in cholesterol was not a result of medication. "Very few of the participants in this study were receiving cholesterol lowering treatment at the time the decline in cholesterol levels was observed, so medication was not responsible for this," Dr. Stewart explained. One can assume that the use of Statins in such people might have hastened the process.
Such information is sobering when one considers the current trend among doctors to prescribe Statins routinely to certain groups (diabetic and post stroke and heart attack) even though cholesterol levels are completely normal.
"The drop in cholesterol was instead probably caused by some other event and was a 'marker' of risk rather than actually increasing the risk itself," Stewart concluded.
Duane Graveline MD MPH
Former USAF Flight Surgeon
Former NASA Astronaut
Retired Family Doctor