Taking a supplement that contains acetyl-L-carnitine, an amino acid, improves absorption and processing of new information, according to an animal study published by researchers at the University of Milan in the Journal of Behavioral and Brain Science.
On paper acetyl-L-carnitine is a promising substance for people seeking to delay their aging process. Cells use acetyl-L-carnitine as a means of transporting fatty acids: acetyl-L-carnitine unloads the fatty acids into the mitochondria, where the fatty acids are converted into energy for the cell.
As organisms age, this mechanism starts to develop errors. Supplements manufacturers believe that acetyl-L-carnitine supplementation can help forestall these errors.
It looks as though animal studies confirm their suspicions. Cells in the brains of aging lab animals that are given acetyl-L-carnitine start to function at a 'young level'. For example, the amino acid maintains levels of production of nerve growth factor. [Exp Gerontol. 1996 Sep-Oct; 31(5): 577-87.] Nerve growth factor is a growth factor for brain cells. Acetyl-L-Carnitine also protects cholinergic neurons, brain cells that play a role in retaining information.
Studies have shown that acetyl-L-carnitine improves learning processes in very old rats [Int J Clin Pharmacol Res. 1990; 10(1-2): 65-8.] but not in middle-aged rats. To help fill the gaps in knowledge the Italians did experiments with one-year-old rats.
The researchers had given half of their lab animals a daily 60 mg acetyl-L-carnitine per kg bodyweight from the age of six months mixed in with their drinking water [ChAT-ALCAR-12]. The other half of the rats were given water with nothing added to it [ChAT-CT-12].
Our estimate of the human equivalent dose is about 10 mg per kg bodyweight per day.
When the rats reached the age of one the researchers made the animals swim in an aquarium with cloudy water. In one corner of the aquarium, a platform was located 1 cm under the water surface, upon which the rats were able to stand. After the rats had discovered the platform the researchers took them out of the water, waited for a period and then put the rats back in the aquarium. They then timed how long it took the rats to find the platform again.
The researchers repeated the procedure a total of four times. [S1, S2, S3 and S4]
The table below shows that the rats that had been given acetyl-L-carnitine took noticeably less time to find the platform again than the rats in the other group.
The researchers may not have been completely objective, however. The experiment described above was not actually performed by the authors, but by unnamed researchers from Sigma-Tau, a manufacturer of acetyl-L-carnitine. The researchers were given ready-made results.
Journal of Behavioral and Brain Science, 2012, 2, 18-25.