The Cholesterol/Alzheimer's Link
Most of us have realistic expectations for when we get older - grey, thinning hair for example, wrinkles for another. Not exactly things anyone really looks forward too, but they seem acceptable payment for a long life full of experiences. These days, with improvements in medical care and a growing population, more and more Americans are living to experience these things, but while this is certainly a positive trend, there is one stark problem - dementia.
Simply put, rates of dementia increase with increasing age. At age 80, 15% experience signs of dementia and by 85, this rate nearly doubles. Despite increases in life expectancy, this rate has remained fixed. So, although we are expecting longer life, these trends also mean that there is a greater chance that we will experience dementia in our lifetime.
For most, the thought of losing our memory and awareness is a frightening thing to consider. Frightening for the government too, who notes dementia presently already costs Medicare $203 billion a year and is expected to soar to $1.2 trillion by 2050 given the trend. As such, as you can imagine, any new findings in the prevention and treatment of dementia draws attention.In particular, there have been some interesting findings lately associating Alzheimer's type dementia to cholesterol. If true, how are they related? What does this mean for us? And how can we use this information to decrease the chance we and our love ones will develop dementia? Let's start from the beginning.
The Rochester Findings
The study, published last week in Nature Medicine last week, is the work of researchers from Rochester University who claim they've identified biomarkers which can accurately predict who will develop Alzheimer's type dementia in the coming years. In the study, which was begun in 2007, seniors from the Rochester area in New York were followed for signs of dementia while a number of biomarkers were examined in their blood. The researchers found 10 specific lipids that, if present in lower than normal levels, could predict with more than 90 percent accuracy whether an individual would go on to develop Alzheimer's.
The Simvastin Statin/Alzheimer's Study
The Rochester findings are the first we've heard about a possible link between cholesterol and alzheimers though. In 2007, a pharmacologist published a paper based on his review of the Veteran's Affairs database of over 4.5 million subjects. He found an association between a single statin cholesterol lowering drug called simvastatin and a reduced rate of Alzheimer's type dementia. Specifically, those who took simvastatin and had a LDL cholesterol level below 100 had cut their risk of dementia in half. Interestingly though, this did not pan out for the other statin medications.
This finding got a lot of attention and the data just made sense. Compared with other statin medications, simvastatin, is more fat soluble while the others are more water soluble. Considering that the brain is mostly fat, if you were going to bet on a statin getting to the brain, your safest choice would be simvastatin. But what does this have to do with Alzheimer's? Considering that the main microscopic finding in Alzheimer's type dementia is a haphazard tangles of nerves, it's believed that perhaps lowering brain cholesterol prevented this process in some way.
Studies since have yielded conflicting results and even Dr. Wolozin, the author of the initial study has questioned the link after more in-depth study on simvastatin and actual brain changes. Nonetheless, it's hard to discount the significance of the initial study given the incredible number of subjects analyzed.
While the Rochester findings involve examining 10 different lipid markers that are low in predicting Alzheimer's, the other speculation links low LDL to reduced risk of Alzheimer's. While things are not clear at this point regarding the concrete knowledge of what causes Alzheimer's and how to prevent it, I can't help feel that these recent findings indicate that we are on the verge of something big.
We know that our body has many lipids -some are good and some are bad when it comes to the prevention of heart disease. It's a leap, but the present knowledge supports (although ambiguously) that lipids and Alzheimer's are linked in some way. As such, it is even more important that we look at our lipid panels and strive to reduce the LDL (bad) cholesterol and increase the HDL (good) cholesterol. (For information on maintaining a healthy cholesterol balance through diet, please check out dietitian Jessica Corwin's article "Foods That Affect Cholesterol - For Better or Worse") With the coming "silver tsunami" of aging baby boomers, research is sure to churn quickly on this subject. Look for further advances in the near future, hopefully toward definitive prevention and treatment of this terrible disease.