Acetyl-L-carnitine remains available over the counter despite safety concerns. Taking this dietary aid offers you many health benefits, according to a 2010 article in "Alternative Medicine Review." For example, it may protect your brain from disease and injury. Scientists can measure the positive effects of carnitine by recording the brain's electrical activity. Brain waves, also called EEG tracings, provide a good indicator for the overall health of the central nervous system. Carnitine affects the brain in distinct ways.
Brain waves vary from a few cycles per second to hundreds of cycles per second. Each frequency plays a unique role in thinking, learning and acting. Researchers consider theta waves -- six cycles per second -- to reflect attention, according to a 2010 report in "Neuroscience Letters." An experiment described in the 2006 edition of "Archives Italiennes de Biologie" looked at the impact of acetyl-L-carnitine on theta waves. Laboratory animals received either carnitine or saline during a single testing session. Relative to a placebo, the supplement increased theta power. The theta waves were faster and more prominent in the rats given carnitine.
Scientists also break down the EEG into unique components. One component -- called the P300 -- reflects reaction time, according to a 2007 review in "Clinical Neurophysiology." When presented with a stimulus, the P300 appears earlier in subjects with shorter reaction times. An investigation published in the 1993 volume of "Electroencephalography and Clinical Neurophysiology" assessed the effect of acetyl-L-carnitine on P300 latency. Primates received carnitine immediately before performing cognitive tasks. The nutritional supplement, relative to an inert treatment, hasted the appearance of the P300 component. Monkeys given carnitine had their shortest P300 latencies within 20 minutes of being given the supplement.
Impact on Sleep
Brain activity varies with changes in behavioral state. Sleep, for example, produces several unique EEG waveforms. One type -- known as sleep spindles -- represent the brain's attempt to keep your body asleep. Healthy sleep includes the frequent appearance of spindling, according to a 2010 article in "Current Biology." A trial presented in the 1990 edition of "Clinical Pharmacology Research" evaluated the impact of acetyl-L-carnitine on brain waves of Parkinson's patients. Subjects received daily doses of carnitine for a week. Relative to baseline, the supplement increased spindling and improved sleep. Large and small doses of carnitine were similarly effective without causing side effects.
Doctors grade brain tracings using a five-point scale, according to the 2007 book "Principles of Clinical Pharmacology." A healthy patient receives a score of 4 and a comatose patient receives a 1. People with hepatic encephalopathy often receive the lowest score. In this medical condition, the liver fails to remove toxic substances from the blood, causing brain damage. A study described in the 2006 volume of "Digestive Diseases and Sciences" tested acetyl-L-carnitine in people experiencing hepatic coma. Patients received either the carnitine or a placebo for several days. Placebo intake improved EEG grade in 9 percent of the subjects, while carnitine intake improved it in 62 percent. The patients did not experience adverse events.
- "Alternative Medicine Review"; Acetyl-L-Carnitine. Monograph; April 2010
- "Neuroscience Letters"; Brain Activity in Goal-Directed Movements in a Real Compared to a Virtual Environment Using the Nintendo Wii; Jochen Baumeister, et al.; Aug. 30, 2010
- "Archives Italiennes de Biologie"; Behavioral and Electrophysiological Changes Induced by Acetyl-L-Carnitine in Aged Freely-Moving Rats; Gabriella Marini, et al.; February 2006
- "Clinical Neurophysiology"; Updating P300: An Integrative Theory of P3a and P3b; John Polich; October 2007
- "Electroencephalography and Clinical Neurophysiology"; Effect of Levo-Acetyl-Carnitine on Visual Cognitive Evoked Potentials in the Behaving Monkey; Andrea Antal, et al.; April 1993
- "Current Biology"; Spontaneous Brain Rhythms Predict Sleep Stability in the Face of Noise; Thien Thanh Dang-Vu, et al.; Aug. 10, 2010