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Benefits
Supports cognitive function*
ALC has been studied for its effect on cognitive performance and emotional
health in the elderly.
In a single-blind, placebo-controlled trial, 481 elderly
subjects exhibiting mild memory impairment improved their scores on a memory
test after taking 1500 mg of ALC a day for 90 days.2 Hospitalized elderly people
taking ALC have shown improvements in mental outlook.3
While ALC is not a treatment or cure for Alzheimer's disease, double-blind
studies suggest it may help slow the rate at which early-stage Alzheimer's
patients deteriorate.4 In particular, ALC seems to benefit short-term memory in
these patients.5
Supports biosynthesis of acetylcholine, a key neurotransmitter for brain and
nerve function*
Brain function requires coordinated communication between brain cells. Brain and
nerve cells ("neurons") communicate across tiny cell-to-cell gaps called
"synapses." The passage of an electrical impulse from one neuron to the next
requires a "neurotransmitter." When an electrical signal arrives at the synaptic
junction, the neuron releases a neurotransmitter into the synapse. The neuron on
the other side of the synapse contains receptors for the neurotransmitter; these
receptors bind the neurotransmitter, triggering a series of chemical events that
sends a new electrical signal down the membrane of the receiving neuron.
Neurotransmitters work together like an orchestra to transmit information
throughout the brain and nervous system.
Acetylcholine is the most abundant neurotransmitter in the body, regulating
activities of vital organs, blood vessels and communication between nerves and
muscles. In the brain, acetylcholine helps facilitate memory and learning as
well as influence emotions. ALC is structurally similar to acetylcholine, and
brain neurons stimulated by acetylcholine are receptive to stimulation by ALC.6
It has been shown experimentally that ALC supplies acetyl groups for the
biosynthesis of acetylcholine.7 ALC's hypothesized cholinomimetic (acts like
acetylcholine) activity has led researchers to investigate its effects on mental
function and emotional health.8
Helps supply the brain with energy by improving energetics in the
mitochondrion*
The acetyl groups donated by ALC can be used to synthesize acetyl-CoA, the key
substrate for energy metabolism in the mitochondrion.9 Acetyl-CoA enters the
Krebs cycle, the mitochondrial mechanism that generates cellular energy in the
form of ATP. ALC easily crosses the blood-brain barrier, allowing it to play
various roles in maintaining brain neuron (nerve cell) function. When given by
oral administration, the concentration of ALC is increased in the blood and
cerebrospinal fluid.10
Stabilizes intracellular membranes*
ALC was found to improve membrane phospholipid metabolism in early-stage
Alzheimer's patients.11 Phospholipids are structural components of brain cell
membranes that regulate neuron function. ALC donates acetyl groups that can be
used to modify the functional activity of proteins in neuronal membranes.12 ALC
thus plays a role in maintaining membrane function. ALC also increases membrane
stability and structural integrity.13
Increases nerve growth factor production*
The body produces various specialized proteins called "growth factors" which are
essential to growth and repair of tissue. Nerve Growth Factor (NGF) protects
neurons from death, prolonging survival of neurons in both the central and
peripheral nervous systems. It is theorized that aging of the central nervous
system is associated with a loss of NGF. ALC has shown the ability to reverse
age-related decrease in the binding of NGF to its receptors in neuron
membranes.14 Given to aged rats, ALC increases the level and utilization of NGF
in the rats. ALC protects cholinergic neurons (nerve cells stimulated by
acetylcholine) in rats from degeneration due to lack of NGF.15 These results,
together with other data from animal studies, suggest that ALC positively
influences NGF activity.16
Has a protective influence on brain neurons*
Several animal studies have revealed that ALC exerts a protective effect on
neurons. In one experiment, brain cells from rats exposed to NMDA, a known
neurotoxin, were protected by being simultaneously exposed to ALC.17 Rats
injected with ALC were protected from mortality caused by the neurotoxin MPP+.18
ALC has been shown to raise levels of glutathione, a highly valuable
antioxidant, in isolated mouse brain tissue.19 ALC prevents buildup of
malondyhaldeyde, a marker of lipid peroxidation.20 ALC is also a chelator of
iron, which can generate free radicals. It also reinforces antioxidant
mechanisms in the brain.21
As a whole, data from test tube and animal studies, showing that ALC has a
protective, restorative effect on brain neurons and neuronal energetic
processes, suggest that ALC is an anti-aging nutrient for the brain. This
hypothesis is supported by human studies demonstrating measurable benefits for
brain function in elderly persons taking ALC by oral consumption.
Scientific References
1. Pettegrew, JW, Levine, J, McClure, RJ. Acetyl-L-carnitine physical-chemical,
metabolic, and therapeutic properties: relevance for its mode of action in
Alzheimer's disease and geriatric depression. Molecular Psychiatry
2000;5:616-32.
2. Salvioli, G. Neri , M. L-acetylcarnitine treatment of mental decline in the
elderly. Drugs Exptl. Clin. Res. 1994; 20(4):169-76.
3. Tempesta, E, et al. L-acetylcarnitine in depressed elderly subjects. A
cross-over study vs. placebo. Drugs Exptl. Clin. Res. 1987;8(7):417-23.
4. Spagnoli, A et al. Long-term acetyl-L-carnitine treatment in Alzheimer's
disease. Neurology 1991;41:1726-32.
5. Rai, G et al. Double-blind, placebo-controlled study of acetyl-L-carnitine in
patients with Alzheimer's dementia. Curr. Med Res. Opin. 1990;11:638-47.
6. Falchetto, S, Kato, G, Provini, L. The action of carnitines on cortical
neurons. Can J Physiol Pharmacol 1971; 49(1):1:7.
7. Dolezal, V., Tucek, S. Utilization of citrate, acetylcarnitine, acetate,
pyruvate and glucose for the synthesis of acetylcholine in rat brain slices. J
Neurochem 1981;36(4):1323.30.
8. Passeri, M, et al. Mental impairment in aging: selection of patients, methods
of evaluation and therapeutic possibilities of acetyl-L-carnitine. Int. J. Clin.
Pharm. Res. 1988;8(5):367-76.
9. Pettegrew, JW, Levine, J, McClure, RJ. Acetyl-L-carnitine physical-chemical,
metabolic, and therapeutic properties: relevance for its mode of action in
Alzheimer's disease and geriatric depression. Molecular Psychiatry
2000;5:616-32.
10. Parnetti, L, et al. Pharmacokinetics of IV and oral acetyl-L-carnitine in
multiple dose regimen in patients with senile dementia of Alzheimer type. Eur.
J. Clin Pharmacol 1992;42:89-93.
11. Pettegrew, JW, et al. Clinical and neurochemical effects of acetyl-L-carnitine
in Alzheimer's disease. Neurobiology of Aging 1995;16(1):1-4.
12. Pettegrew, JW, Levine, J, McClure, RJ. Acetyl-L-carnitine physical-chemical,
metabolic, and therapeutic properties: relevance for its mode of action in
Alzheimer's disease and geriatric depression. Molecular Psychiatry
2000;5:616-32.
13. Arduni, A, et al. Effect of L-carnitine and acetyl-L-carnitine on the human
erythrocyte membrane stability and deformability. Life Sci
1990;47(26):2395-2400.
14. Taglialatela, G, et al. Stimulation of nerve growth factor receptors in PC12
by acetyl-L-carnitine. Biochem Pharmacol 1992;44(3):577-85.
15. Taglialatela, G, et al. Acetyl-L-carnitine treatment increases nerve growth
factor levels and choline acetyltransferase activity in the central nervous
system of aged rats. Exp Gerontol 1994;29(1):55-56.
16. Pettegrew, JW, Levine, J, McClure, RJ. Acetyl-L-carnitine physical-chemical,
metabolic, and therapeutic properties: relevance for its mode of action in
Alzheimer's disease and geriatric depression. Molecular Psychiatry
2000;5:616-32.
17. Forloni, G, Angeretti, N, Smiroldo, S. Neuroprotective activity of acetyl-L-carnitine:
studies in vitro. J Neurosci Res 1994;37(1):92-6.
18. Steffen, V, et al. Effect of intraventricular injection of
1-methyl-4-phenylpyridinium: protection by acetyl-L-carnitine. Hum Exp Toxicol
1995;14(11):865-71.
19. Fariello, RG, et al. Systemic acetyl-L-carnitine elevates nigral levels of
glutathione and GABA. Life Sci 1988;43(3):289-92.
20. Calvani, M, et al. Action of acetyl-L-carnitine in neurodegeneration and
Alzheimer's disease. Ann Ny Acad Sci 1992;663:483-86.
21. Calvani, M, Carta, A. Clues to the mechanism of action of acetyl-L-carnitine
in the central nervous system. Dementia 1991;2:1-6.
22. Zdanowicz, M. Acetyl-L-carnitine's healing potential. Continuing Education
Module. New Hope Institute of Retailing. October, 2001.
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