Mid-Life High Cholesterol Levels Linked to Higher Risk of Late-Life Dementia
A new study by researchers at Kaiser Permanente’s Division of Research and the University of Kuopio in Finland recently concluded that elevated levels of cholesterol in mid-life influence the risk of developing Alzheimer’s Disease or vascular dementia later in life. This study tracked nearly 10,000 people for four decades, starting when the participants were between 40 and 45 years of age. After controlling for weight, hypertension, and diabetes, the study found the following:
1) Participants who had high cholesterol, or a value of 240 mg/dl or more, had a 66 percent greater risk of developing Alzheimer’s Disease later in life, and
2) People with borderline-high cholesterol, between 200 and 239 mg/dl, had a 25 percent spike in risk.
This study merits our attention for two reasons: First, although previous studies have linked heart and brain health, this is one of the first studies to examine the association between borderline high cholesterol levels and dementia. Second, the study’s sample size and design weigh in its favor. Long-term cohort studies (also known as Prospective Studies) that: i) have a substantial sample size; ii) measure study endpoints both through and at the completion of a considerable length of time (in this case, four decades); iii) control for important confounding variables; and, iv) do so across a diverse study population – give us some of the most valuable information in research.
As millions of individuals in Western nations have borderline or high cholesterol levels during mid-life, I am certain that many may be alarmed by the results of this study. The good news, however, is that for most individuals, a combination of sound dietary habits, moderate exercise, and a conscious effort to reduce stress levels can help achieve healthy – or even optimal – cholesterol profiles. Further, a large body of corroborative epidemiologic research suggests that a diet rich in quality whole grains, abundant fresh fruit and vegetables, mono-unsaturated fats such as olive oil, largely vegetarian proteins such as legumes, and a limited amount of red meat can contribute substantially to achieving a healthy lipid profile.
By now, we know what a quality whole-foods diet (that is based largely on plant foods) and moderate daily exercise can do for us. This study is one more reason to – Just do it!
Hello from Canada
I’m curious about this research – mostly because a number of well-publicized studies on cholesterol have been funded by pharmaceutical companies who manufacture statins. This financial relationship casts some doubt on the results compard to independent, non-sponsored studies. As a heart attack survivor and a 2008 graduate of the WomenHeart Science & Leadership Symposium for Women with Heart Disease at Mayo Clinic in Rochester last fall, I’m very interested in the alarming growth of Big Pharma-driven research and its ramifications to clinical guidelines. Many journals disclose conflicts of interests for study authors, but sadly, many have dropped their editorial policies of refusing studies authored by scientists who take money from the companies who stand to gain by this research.
Was this research published, and if so where? And who funded the research?
Thanks!
Carolyn Thomas
http://www.myheartsisters.org
Hello Carolyn:
Thank you for your comment. I am pleased to see that there are readers who view published research with a critical eye – as they should.
If you are able to take out some time, please click on “About this Site” on the navigation bar, as well as read all the way down on the Biography page – You will notice that one of the points I reiterate is the use of OBJECTIVE CRITERIA when evaluating any health-related information – whether it pertains to diets, drugs, supplements, or health advice in general. So, you happened to have found a researcher in full sympathy with your position. And, yes, it is getting harder in these times to obtain truly objective information – Thus, I consider it all the more important – given my position – to help readers sift truth from error (or fiction) in research.
To answer your question directly, the study in question was published online on Aug 4, 2009 in The Journal of Dementia and Geriatric Cognitive Disorders. At the bottom of this reply, I have provided a link to the study. The last page (Acknowledgements) lists the grants through which the study was funded.
A savvy or experienced researcher evaluates the quality of a study using the following minimum criteria: Study design/methodology, sample size, length of time of study, appropriateness and accuracy of statistical analysis, proper control of a range of confounding variables, and study affiliations/conflicts of interest, if any. On all accounts, this study appears to be satisfactory.
If you read through the study carefully, you will learn that although elevated cholesterol has been cited as the main connection with AD and Dementia, it was clearly observed that a medical history of higher Body Mass Index, hypertension, diabetes or stroke was significantly more common in patients with AD or Vascular Dementia. As is expected, there usually is a constellation of factors that contribute to precipitating disease.
Generally speaking, no ONE study (this or another) should be taken as the final arbiter for making critical decisions with respect to dietary or clinical guidelines. Solid information depends on a body of corroborative evidence. This study does, however, build on previous knowledge of known risk factors for late life Dementia – and the collective body of research appears to indicate that cardiovascular and neurological/cognitive problems may be closely related. Still, I don’t think this constitutes adequate reason for us to run to the pharmacist for anti-cholesterol drugs. I believe that long-term health should be built first and foremost on quality nutrition. If more people truly observe that maxim, the majority of drugs might run the risk of becoming obsolete.
It is important to view studies very critically – Please continue to do so. It is also important to take the results of valid studies seriously. The key obviously is learning how to distinguish truly valid from poor studies – and there is a lot to it! I often teach classes on this very subject, and would be pleased to invite you as a guest if you are interested.
Finally, as an example of critiquing a study constructively, you may enjoy reading my Aug 4 post, titled COMMENTARY ON: British Study on Organic Foods.
Here is a link to the Cholesterol/Dementia link study:
http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ArtikelNr=231980&Ausgabe=250346&ProduktNr=224226&filename=231980.pdf
I hope the above helps.
Desiree Jones, PhD