A friend recently asked us the question: “I would love to find out what you think about the thought-provoking article regarding a breakthrough against Alzheimer’s disease.”
It’s hardly any wonder people are intrigued. The headlines have been tantalizing.
Forbes offered this:
“From Taiwan, A Long Hoped-For Breakthrough In The Fight Against Alzheimer’s”
A doctor’s news service suggested:
“Statins Could Protect Against Dementia”
So what is the straight and skinny on statins and dementia? Will drugs like atorvastatin (Lipitor), lovastatin (Mevacor), pitavastatin (Livalo) rosuvastatin (Crestor) and simvastatin (Zocor) really protect you from cognitive decline or Alzheimer’s disease?
The answer is complicated. The most recent study, published in the journal PLOS (Feb. 2014), was an epidemiological analysis of patients with type 2 diabetes. These Taiwanese subjects were part of the National Health Insurance Research Database. Roughly 16,000 patients with type 2 diabetes had never used statins, while 2,400 diabetic patients regularly used these cholesterol-lowering medications.
Patients with type 2 diabetes are a bit like canaries in the coal mines in that they are at increased risk for developing dementia. In this retrospective study, the investigators found that regular use of statins such as atorvastatin or simvastatin seemed to reduce the risk of Alzheimer’s-type dementia by about 25 percent. There was no such reduction for other forms of dementia such as multi-infarct or vascular dementia. These other kinds of cognitive diseases are responsible for about one third of all dementias.
The findings of this study led the contributor to Forbes to describe statins as “a long hoped-for breakthrough in the fight against Alzheimer’s disease.” He also disclosed that he owns “stock in AstraZeneca, one of the companies mentioned in this commentary.” AstraZeneca makes Crestor, one of the most profitable statins sold in the U.S.
Before we provide color commentary on the question of statins as brain protectors and Alzheimer’s preventers, we need to clarify the difference between a retrospective epidemiological study and a randomized controlled trial (RCT). Epidemiological or observational studies can only suggest a possible association between a drug and an outcome. They cannot prove cause-and-effect.
Many such epi studies reported that hormone replacement therapy (HRT) lowered the risk of heart disease and strokes in women until an actual randomized controlled trial (the Women’s Health Initiative) proved once and for all that HRT actually raised the risk of heart attacks and strokes (and breast cancer).
RCTs are the gold standard when it comes to determining drug benefits. In a “blinded” protocol, patients are randomized to receive either active drug or inactive placebo. Neither doctors nor patients know who gets what.
So, what do the RCTs tell us about statins and Alzheimer’s disease? The PROSPER trial involved 5,804 men and women between 70 and 82 years of age. They were randomized to receive either placebo or 40 mg of pravastatin. After 3.2 years the researchers found that “Pravastatin had no significant effect on cognitive function or disability.”
Another study involving 20,536 high-risk individuals randomized people to either 40 mg of simvastatin or placebo for roughly five years. The investigators found that “…no significant differences were observed between the treatment groups in the percentages of participants classified as cognitively impaired… Similar numbers of participants in each treatment group were reported to have developed dementia during follow-up…”
Finally, an “international, multicenter, double-blind, parallel-group study” involved 640 patients with mild to moderate Alzheimer’s disease who were given either 80 mg of atorvastatin or placebo for 72 weeks. The results:
“Atorvastatin does not slow cognitive decline in patients with mild to moderate probable Alzheimer’s disease…”
An evaluation by the Cochrane Collaboration, a large group of independent experts reviewed all the available data on statins in the treatment of dementia. They concluded:
“There is insufficient evidence to recommend statins for the treatment of dementia. Analysis from the studies available, including one large RCT, indicate statins have no benefit on the outcome measures ADAS-Cog [Alzheimer's Disease Assessment Scale- cognitive subscale] or MMSE [Mini Mental State Examination].”
People’s Pharmacy Color Commentary:
Observational studies like the one from Taiwan are enticing, but they do not represent a “breakthrough” against Alzheimer’s disease. Such drugs are clearly NOT a cure for the disease. And it remains unclear whether they will actually prevent dementia. If there is an effect, we suspect it might be because of an anti-inflammatory action rather than any cholesterol-lowering effect. We think cholesterol is essential for brain function.
We have also received a great many reports of brain fog, cognitive dysfunction and dementia-like symptoms associated with statins. We cannot prove that statins cause forgetfulness, memory problems or confusion, but many visitors to this website are convinced that they do. Here are links to some pages that suggest such a connection in selected patients.
Share your own experiences with statins below. Have you experienced brain fog or memory problems or do you think statins are helping protect you against dementia. We would love to read your story. Those that would like to learn about other ways to control cholesterol may find our Guide to Cholesterol and Heart Health of value.