CDP-choline is a form of the B-vitamin choline. It is an intermediate in the synthesis of components of cell membranes and
of the neurotransmitter acetylcholine. It also is a precursor of betaine, which is involved in gene regulation.
The biochemistry of CDP-choline has been studied since the 1950s and its clinical use began in the 1960s as a treatment for
brain injuries. Progress has been very slow, perhaps because the potential applications of the substance were patented and were then subjected
to financial and legal game-playing by the patent owner and licensees. Development was further plagued by clinical studies
that sometimes reached conflicting results. Even now there is not yet a consensus on optimum dosages for various conditions.
Nevertheless, interest in this supplement remains high; and there is general agreement that it offers a degree of protection
against various kinds of damage to the nervous system (including the retina and optic nerve).
The neuroprotective effects of CDP-choline may derive from its ability to increase the synthesis of phosphatidylcholines in
injured nervous tissue. Phosphatidylcholines are major components of cell membranes.
What we can’t tell you
In the U.S. and some other industrialized countries, government agencies like the U.S. Food and Drug Administration have adopted
censorship as a method for intensifying their control over the supplement industry and its customers. Thus, FDA regulations
prohibit us from telling you that any of our products are effective as medical treatments, even if they are, in fact, effective.
Accordingly, we will limit our discussion of CDP-choline to a brief summary of relevant research, and let you draw your own
conclusions about what medical conditions it may be effective in treating.
CDP-choline has been the focus of countless experiments using cell culture and lab animals, and many thousands of human volunteers
and patients have participated in clinical studies of this compound. There is now considerable evidence that CDP-choline has neuroprotective and neuro-regenerative effects that can ameliorate
the following conditions:
- glaucoma-related damage to the eye
- amblyopia (poor vision in one eye; “lazy eye”)
- Alzheimer’s Disease
- Parkinson’s Disease
- age-related learning and memory disorders
- traumatic brain injury
- stroke
- drug addiction
CDP-choline as a treatment for visual problems
Two kinds of vision problems have been shown to be improved by CDP-choline supplementation. Both are problems stemming from
damaged nerves.
Glaucoma results from damage to nerve cells which transmit information from the retina into the brain. Treatment of glaucoma
patients with oral CDP-choline (1600 mg/day for 60 days) resulted in “Improvement of retinal function (objectively evaluated
by pattern electroretinogram recordings) and of neural conduction along visual pathways…”
Amblyopia (a.k.a. “lazy eye”) is a visual disorder in which one eye has poor vision despite having no significant defect in
the eye itself. It is thought to be caused by damage to the brain's visual centers or to the optic nerve. CDP-choline has
been tested in children with amblyopia and found to improve visual acuity, contrast sensitivity, and strength of visual responses. When combined with patching, it leads to more stable benefits than those achieved with patching alone.
CDP-choline for Alzheimer’s and Parkinson’s
When CDP-choline was administered to early-to-mid-stage Parkinson’s patients it led to significant improvement in symptoms.
Advanced Parkinson’s patients appeared not to benefit from the treatment.
A number of clinical trials have demonstrated an ability of CDP-choline to reverse the cognitive symptoms of Alzheimer’s Disease.
For example, in 1999 Spanish researchers reported that 1000 mg/day of CDP-choline “…Improves cognitive performance, cerebral
blood perfusion and the brain bioelectrical activity pattern in AD patients.” The treatment was more effective in some types
of Alzheimer’s Disease than in others.
CDP-choline’s action against Alzheimer’s symptoms may be due in part to its ability to keep nerve cells alive under conditions
that normally would cause them to self-destruct. Some of the damage done to the brain by Alzheimer’s Disease is thought to
be due to the triggering of cell suicide (“apoptosis”) by the plaques of amyloid protein that are a hallmark of the disease.
A study in 1999 implanted amyloid protein in various parts of rats’ brains. Those rats that were also treated with CDP-choline
suffered less neurodegeneration and performed better in cognitive tests than rats that received no CDP-choline.
Other age-related cognitive problems
Phosphatidylcholine — a major component of brain cell membranes — is produced by the body in decreasing amounts as one ages.
It is thought that this decline lowers the efficiency of signaling between nerve cells, and therefore impairs the processing
of information in the brain.
Supplementation in “older subjects” with CDP-choline (500 mg/day for 6 weeks) has been shown to promote synapse formation
and efficiency, and to improve performance on the California Verbal Learning Test.
Traumatic brain injury
The toll taken by traumatic brain injury is enormous — every year, approximately 1.4 million Americans sustain such an injury,
of which 50,000 die, another 235,000 are hospitalized, and 80,000–90,000 people suffer permanent disability.
At long last, a major clinical trial has been organized to find out whether CDP-choline’s benefits in stroke and dementia
can be translated into a treatment for traumatic brain injury. The trial, called COBRIT, started in 2007 but is still recruiting
participants (as of April 2010); it is scheduled to be completed in December 2010. We eagerly await the results, which we anticipate will catapult CDP-choline into a first-line treatment for such injuries.
Stroke
CDP-choline as a treatment for stroke has received a considerable amount of research attention. The evidence suggests that
if stroke patients are treated with 2000 mg of CDP-choline within the first 24 hours after having the stroke, their probability
of complete recovery at 3 months will be increased by about 8%.
Schizophrenia
In a recent collaboration between LifeLink and researchers at Georgetown University and the U.S. Department of Veterans Affairs,
a new application for CDP-choline has been shown: treatment of schizophrenia. Researchers previously had suspected that at
least some aspects of schizophrenia may be caused by a defect in a molecular channel in nerve cell membranes — specifically,
a defect in the alpha7 nicotinic acetylcholine receptor located in this channel. That suspicion has now been confirmed by
a 12-week-long clinical trial in which patients were given a combination of CDP-choline (supplied by LifeLink) and the drug
galantamine; the trial showed that 5 out of 6 subjects receiving this treatment experienced a “reduction in Clinical Global
Impressions severity scores and Positive and Negative Syndrome Scale total scores.”
Side effects
CDP-choline typically is without side effects. Rarely a few users experience digestive intolerance, gastrointestinal discomfort
or restlessness.
Bioavailability
When taken orally CDP-choline is converted in the intestine into cytidine and choline, both of which are efficiently absorbed
into the bloodstream. These components are then transported throughout the body where they are utilized in various biosynthetic pathways. A small fraction of the cytidine and choline pass through the blood-brain barrier and are converted in the brain back into
CDP-choline.
The brain-bioavailability of CDP-choline is therefore low, since the majority of the consumed dose is used (or wasted) outside
of the brain. Fortunately the substance is not prohibitively expensive and the low brain-bioavailability can be compensated
for by using fairly large doses — 1000 mg/day, for example. The lack of toxicity of the supplement makes this possible without
causing significant side effects.
Conclusion
Are CDP-choline supplements useful for the conditions and purposes mentioned above? We aren’t allowed to tell you, so you
should take a look at some of the references cited here, and then decide for yourself.