The take home is that memory impairment is an issue. It must be
closely monitored and dosage levels minimized at least. Recent work
also suggests that a high intake of coconut product is useful to
counter the effects..
It is also correct to say that the negative effects apply to a small
population and can be recognized as a possible side effect to be
guarded against.
Statins continue to collect controversy and concerns. However
certain critical variables have been recognized and it is high time
we conducted a massive study that tracks all the attendant variables
and their treatment variations. This can and will provide clear
guidence.
Do Statin Drugs
Cause Memory Loss?
by Chris D. Meletis,
N.D.
Statins, used to lower
cholesterol, are one of the most commonly prescribed drugs. You’ve
likely heard that they come with a lot of side effects. But there’s
one possible side effect you might not have heard too much about—the
possibility that statins may cause memory loss.
If you’re like most
people, you probably think of cholesterol as the villain. However,
cholesterol plays some important roles in the body. Without it, your
body wouldn’t be able to produce cell membranes, hormones, vitamin
D or bile acids that help digest fat. Cholesterol also is necessary
for cognitive and neurological function.
Based on the important
role that cholesterol plays in cognitive function, it’s not
surprising that reports have started to turn up that statins may
damage memory.
Prevent Dementia…Or
Cause It?
Reports of people who
have suffered severe memory problems after taking statin drugs came
as a surprise to researchers and doctors, given that several studies
suggest statins may actually preventdementia or Alzheimer’s.
However, the evidence for statin’s possible memory-enhancing
effects shows that there are just as many studies showing statin
drugs don’t prevent dementia and Alzheimer’s as there are to
suggest they do.
Some of the studies
showing that the drugs improve memory have been done in mice. For
example, the statin drug simvastatin (Zocor®) fully restored short-
and long-term memory in adult mice in an animal model of Alzheimer’s
disease (AD). This same effect wasn’t seen in aged mice. The
statins appeared to normalize genes related to learning and memory,
and had beneficial effects on neurons.1
The researchers
concluded, “Simvastatin and, possibly, other brain penetrant
statins bear high therapeutic promise in early AD and in patients
with vascular diseases who are at risk of developing AD.”
In another study in
India, this one conducted on humans, atorvastatin (Lipitor®)
improved memory and psychomotor functions.2 Another human study
found that atorvastatin prevented the development of dementia.3
However, plenty of
other studies have reached the opposite conclusion.
One study investigated
the effect of atorvastatin on memory in patients with high blood
pressure, a condition known to result in cognitive impairment.
Researchers found no significant difference in memory and psychomotor
functions (the relationship between cognitive function and physical
movement) between patients receiving atorvastatin and those not
receiving the drug.4
Another study
evaluated the effects of lipid-lowering agents on cognitive function
in 6,830 community-dwelling elderly persons (i.e., a retirement
community). Cognitive performance, clinical diagnosis of dementia and
the use of fibrate (a non-statin cholesterol lowering agent) and
statins were evaluated at the study’s start and after two, four and
seven years. For both genders, no significant associations
were found between statins and either cognitive decline or dementia
incidence. This study found no evidence that lipid-lowering agents
given in late life reduced the risk of cognitive decline and
dementia.5
Finally, a study by
University of Washington researchers followed 2,798 older patients
(average age 75) who had no signoff cognitive problems at the start
of the study. The researchers gave the patients memory and cognitive
skills tests and noted which patients developed dementia and
Alzheimer’s over six years. They also noted any statin drug use
among the subjects.
The results? Patients
taking statins developed dementia or Alzheimer’s at a similar rate
as those not taking the drugs.6
Statins and Memory
Loss
Based on the studies
mentioned above, it’s safe to say the jury is still out on whether
statins improve memory or prevent Alzheimer’s. Much of the
evidence, however, indicates they don’t improve memory.
Worse yet, there may
be evidence that statins actually cause memory loss.
One example can be
found with Duane Graveline, M.D. Dr. Graveline is a former NASA
astronaut and flight surgeon who was given Lipitor® after his total
cholesterol hit 280. Six weeks after he started taking the drug, he
developed transient global amnesia, a form of memory loss where you
can’t form new memories or remember the last syllable spoken to
you. In addition, this form of amnesia affects long-term memory as
well.7
Dr. Graveline’s
doctors assured him his memory loss had nothing to do with Lipitor®.
But Dr. Graveline stopped taking it anyway—and the amnesia didn’t
return. His doctors urged him to begin taking the Lipitor® again. He
finally gave in and went on half the dosage he was taking before: 5
mg instead of 10 mg. Eight weeks later, he had another episode of
transient global amnesia—this one worse than before.
The amnesia episodes
haven’t returned since he discontinued the drug. This convinced Dr.
Graveline that statins were to blame for his severe memory problems.
Since then, he has maintained a website on the subject, where 22
cases of transient global amnesia, along with hundreds of cases of
cognitive damage, were reported by people writing in about their
experiences after taking statins.
In addition, more than
2,000 cases of transient global amnesia associated with the use of
statins have been reported to FDA’s MedWatch, and the agency
required memory loss to be added as a side effect on the drugs’
labels. Dr. Graveline also has written a book called Lipitor®:
Thief of Memory.
Lipitor® does appear
to be the worst offender of the statins, while statins that are less
fat soluble—for example, pravastatin (Pravachol® or Selektine®)
and rosuvastatin (Crestor®)—may be less likely to contribute to
cognitive impairment, since they can’t cross the blood-brain
barrier as easily as other statins.8
Why Would Statins Rob
Memories?
Statins interfere with
substances important for memory formation such as cholesterol and
coenzyme Q10 as well as dolichols, biochemicals that transport
genetic instructions from your DNA in order to help manufacture
specific proteins. Dolichols play an important role in cellular
processes and influence all the hormones involved with your emotions
and moods. If you don’t have sufficient dolichol, your entire
process of neurohormone production will be altered in a way that
could affect both your mood and your memory.
At the same time,
statins damage mitochondrial DNA and brain cells. In the brain, glial
cells manufacture the cholesterol the brain needs for cognitive
function. Statins stop the glial cells from producing cholesterol in
the same way they stop your liver from producing it. The result is
that your brain isn’t getting enough cholesterol to function
effectively.
Nature’s Cognitive
Enhancer
Many studies show just
how important cholesterol is for the brain. In one study, researchers
investigated what kinds of cholesterol are associated with better
memory in 193 subjects 80 or older who were free of dementia.
For anyone used to
hearing LDL “bad” cholesterol called the villain, the results
were surprising. Higher low-density lipoprotein cholesterol levels
were associated with higher scores in memory performance. The same
was true for lower triglyceride/high-density lipoprotein cholesterol
ratios.9
In another study, rats
were given either a regular diet or a cholesterol-enriched diet for
two months. The researchers then determined how the two diets
impacted learning and memory, as well as other effects on the brain.
They found that compared to rats on the regular diet, rats fed the
cholesterol-enriched diet performed better in a water maze test used
to gauge learning and memory and in an object recognition test. The
memory improvement came with other beneficial effects on the
structure of the brain.10
Cholesterol Is Only
Part of the Story
Cholesterol is only
one aspect of heart health. In fact, half of those hospitalized with
coronary artery disease symptoms had normal LDL levels (under 100
mg/dl), while 75 percent of those who had a heart attack also had
normal LDL levels.11 Another study published in 2004 showed that
50 percent of people having a cardiovascular event had normal
cholesterol levels.12
The oxidation of LDL
cholesterol is something else to consider. Oxidation is the process
that causes metal to rust and fats to turn rancid.
The same process can
occur in your body, changing your LDL cholesterol from a form that is
beneficial to one that actually damages your body. In this way, it’s
not the LDL per se that damages the body but rather the oxidized LDL.
Fibrinogen, C-reactive protein and homocysteine are all other factors
that can play a role in whether your heart is healthy or not.
Each of those factors
should be tested to ensure optimal heart health, while at the same
time working on balancing levels of LDL and HDL cholesterol. The keys
to make sure your cholesterol doesn’t plummet too low. Anything
below 160mg/dl and you’re putting yourself at risk for cognitive
decline.12 People who have cholesterol below 160 also have a risk of
increased morbidity and mortality, aggressiveness and suicide.13
Lowering Cholesterol
Levels Safely
There are ways to
balance your cholesterol naturally, including lifestyle measures.
Researchers have discovered that exercise and dieting can actually
encourage the production of HDL, the good cholesterol. They found
that in overweight people with type 2 diabetes who started an
exercise program and calorie-restricted diet, fat cells produced more
of a hormone that increases HDL cholesterol production in the
liver.14
Additionally, when
my patients limit their consumption of refined carbohydrates (white
bread and pasta and anything made from white flour) as well as sugar,
agave nectar and high fructose corn syrup, their triglyceride levels
plummet.
Beyond lifestyle
measures, if your cholesterol is really high and you need to bring it
down to a balanced level that won’t damage your cognitive function,
one possible solution is guggulipid. Many clinical studies
demonstrate that guggulipid effectively lowers LDL cholesterol and
triglyceride levels and increases HDL cholesterollevels.15-16
Striking the Right
Balance
Cholesterol has many
beneficial effects in the body. One of those effects is brain health.
Reducing cholesterol to a level that’s too low may have disastrous
effects on cognitive health. There have been enough cases of
statin-related amnesia reported both in the medical literature and in
clinical practice among doctors, to cause concern.
References:
1. Tong XK, et al. J
Neurosci. 2012 Apr 4;32(14):4705-15.
2. Parale GP, et al.
Eur J Clin Pharmacol. 2006;62:259-65.
3. Jick H, et al.
Lancet 2000;356:1627-31.
4. Prajapati S, et al.
J Postgrad Med. 2011 Oct-Dec;57(4):291-7.
5. Ancelin ML, et al.
J Alzheimers Dis. 2012;30(3):629-37.
6. Rea TD, et al. Arch
Neurol. 2005;62(7):1047-51.
7. www.spacedoc.com
8. Rojas-Fernandez CH,
et al. Ann Pharmacother. 2012 Apr;46(4):549-57.
9. Katsumata Y, et al.
J Alzheimers Dis. 2012 Dec 3. [Epub ahead of print.]
10. Ya BL, et al.
Neurol Sci. 2012 Nov 28. [Epub ahead of print.]
11. Sachdeva A, et al.
Am Heart J. 2009;157(1):111-7.
12. Stampfer MJ, et
al. Circulation. 2004;109(25 suppl 1):IV3-IV5.
13. Robles Bayón A,
et al. Neurologia. 2012 Oct 9. [Epub ahead of print.]
14. Belalcazar LM, et
al. Journal of Lipid Research. December 2012;53:2726-33.
15. Nityanand S, et
al. J Assoc Physicians India. 1989;37:323-8.
16. Singh RB, et al.
Cardiovasc Drugs Ther. 1994;8:659-64.
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