¶ Acetyl-L-Carnitine (ALCAR)
¶ Overview
Acetyl-L-Carnitine (ALCAR) is the acetylated form of L-Carnitine, an amino acid derivative involved in energy metabolism. Unlike regular L-Carnitine, ALCAR easily crosses the blood-brain barrier. It serves a dual role: it transports fatty acids into mitochondria for beta-oxidation (energy production) and provides an acetyl group for the synthesis of the neurotransmitter acetylcholine.
¶ Mechanism of Action
- Mitochondrial Bioenergetics: ALCAR facilitates the transport of long-chain fatty acids into the mitochondrial matrix, where they are burned for fuel. This is particularly crucial for neurons, which have high metabolic demands[1].
- Acetylcholine Synthesis: The acetyl moiety of ALCAR can be transferred to Coenzyme A to form Acetyl-CoA, which then combines with choline to produce acetylcholine, the neurotransmitter essential for memory and focus.
- Membrane Stability: It helps maintain the lipid structure of neuronal membranes and may increase the level of Nerve Growth Factor (NGF) receptors.
¶ Clinical Evidence
¶ Cognitive Decline and Aging
ALCAR has been extensively studied in elderly populations. Meta-analyses suggest it can improve cognitive performance in patients with Mild Cognitive Impairment (MCI) and early Alzheimer's disease, particularly in domains of attention and memory[2].
¶ Depression
Several studies indicate ALCAR has rapid antidepressant effects, particularly in older adults or those with dysthymia. A meta-analysis compared ALCAR to established antidepressants and found comparable efficacy with fewer side effects[3].
¶ Peripheral Neuropathy
ALCAR is effective in reducing pain and improving nerve regeneration in neuropathies (e.g., diabetic neuropathy, chemotherapy-induced neuropathy).
¶ Dosage and Safety
- Dosage: Standard dosage is 500–1,500 mg per day, usually divided into two doses.
- Safety: Generally safe. High doses can cause nausea, agitation, or a "fishy" body odor (though less common than with L-Carnitine).
- Interactions: May increase the effect of blood-thinning medications.
¶ References
Traina, G. (2016). The neurobiology of acetyl-L-carnitine. Frontiers in Bioscience. ↩︎
Montgomery, S. A., et al. (2003). Meta-analysis of double blind randomized controlled clinical trials of acetyl-L-carnitine versus placebo in the treatment of mild cognitive impairment and mild Alzheimer's disease. International Clinical Psychopharmacology. ↩︎
Veronese, N., et al. (2018). Acetyl-L-carnitine supplementation and the treatment of depressive symptoms: a systematic review and meta-analysis. Psychosomatic Medicine. ↩︎