As a commonly used bodybuilding supplement, Acetyl-L-Carnitine stands out largely due to its ability to promote fat metabolism. Researchers have learned much more about the benefits and capabilities of this over-the-counter supplement. Read on as we explore all the ways in which Acetyl-L-Carnitine might serve as a powerful addition to anyone’s bodybuilding supplement line-up.
Crash Course in Chemistry
To fully understand how Acetyl-L-Carnitine benefits the body of an athlete, we must first discuss a bit of chemistry. The acetyl group, the small part of a molecule composed of a carbonyl group linked to a methyl group, consists of the following: an atom of carbon double bonded to an atom of oxygen, and a carbon atom linked to three atoms of hydrogen.
The acetyl group allows Acetyl-L-Carnitine to cross the blood-brain barrier, which standard L-Carnitine cannot do. In this configuration, it serves as a supplement that can enhance brain performance while supporting the body’s energy production. Also, this chemical design makes it ideal for supporting the production of acetylcholine, a powerful neurotransmitter tied to memory, focus and learning.
Acetyl-L-Carnitine and Depressive Disorder
According to a study conducted at Stanford University School of Medicine, individuals suffering from depression tend to have diminished blood levels of Acetyl-L-Carnitine, especially those whose bouts of severe depression began early in life.
Clinical depression ranks as the most prevalent mood disorder in both the United States and the world, affecting 8-10% of the general population at any given time. A leading cause of suicide, and the #1 reason why individuals miss work, experts in the field of Psychiatry observe that the current line-up of pharmaceutical medication commonly used to treat depressive disorders only proves effective for about 50% of patients. The numerous side effects of these drugs often lead to patients discontinuing treatment, making long-term compliance a real problem.
Among those test subjects with the lowest serum levels of Acetyl-L-Carnitine, scientists noted a history of childhood abuse, neglect, poverty and/or exposure to violence, in addition to exhibiting severe, treatment-resistant symptoms.
Dr. Natalie Ragson, who spearheaded this research, acknowledges that more work needs to occur in order to establish clear guidelines for dosage, frequency, and treatment duration when using Acetyl -L-Choline for improving depression symptoms.
Treating Peripheral Neuropathy
Acetylcholine, a primary neurotransmitter in the brain, is released by a nerve cell (or neuron) that causes muscles to contract. In doing so, it activates pain responses while also regulating endocrine and REM sleep functions. Acetyl L-Carnitine helps to form acetylcholine.
Acetyl-L-Carnitine supplementation seems to offer an effective and safe treatment for painful peripheral neuropathy, especially as it presents itself in diabetic patients. To assess its global efficacy, scientists looked at four randomized controlled trials, all including patients with neuropathy secondary to diabetes and to anti-retroviral therapy for HIV. Compared to the performance of a placebo, Acetyl-L-Carnitine elicited a significant pain reduction, equal to 20.2% with respect to a baseline level. Clinical trials also showed beneficial effects on nerve conduction parameters and nerve fiber regeneration, with a good safety profile.
These data indicate that Acetyl-L-Carnitine can provide an effective and safe treatment in patients with painful peripheral neuropathy. The pain reduction induced by this supplement may come about as a result of both a neuroprotective and a central anti-nociceptive mechanism. Future studies should investigate the role of the two mechanisms, as well as assess the duration of therapeutic efficacy and an optimal treatment dosage.
Fat Metabolism
In the human body, blood carries triglycerides to the cells where they get converted to energy in the mitochondria, or the “powerhouse” of our cells. L-Carnitine helps to mobilize fat from the body’s storage deposits, shuttling it to be utilized as fuel/energy for workouts. As a result, scientists have deemed L-Carnitine worthy of having a significant role in weight loss, reflecting its popularity among competitive bodybuilders, particularly in the weeks leading up to a show.
Acetyl L-Carnitine accomplishes everything regular L-Carnitine does, in addition to crossing the blood-brain barrier and supporting cognitive function. Therefore, when the question arises as to which chemical form of Carnitine to use on a regular basis, either one will serve to metabolize fat and foster weight loss.
Studies of carnitine supplements in middle-aged adults living with type 2 diabetes have generated mixed results. One 6-month study found no effect at all on weight loss. However, another study found that individuals who took the weight-loss drug Orlistat in addition to carnitine supplements for 1 year lost an average of 4 pounds more than those on a regimen of Orlistat alone. Other studies also found that people who took carnitine supplements lost more weight than those who received a placebo, but the difference was small—only a few pounds. Larger studies conducted in the future may help to clarify the effects of carnitine supplements on weight loss.
Dosing
As we discussed previously, many athletes choose to supplement with both standard L-Carnitine as well as Acetyl -L-Carnitine, particularly if their goals lie in improving cognitive function along with physical performance. Such stacking enables the user to capitalize on each molecule’s advantages.
To maximize cellular uptake, experts recommend taking a standard L-Carnitine supplement with a carbohydrate-rich meal before a heavy workout. The acetyl version boasts a better absorption rate, and therefore, one can safely consume it between meals or on an empty stomach. When taken first thing in the morning, users often report better focus/mental clarity throughout the day.
The human body needs approximately 15 mg of carnitine/day for optimal functioning. While a varied meal plan tends to suffice, some vegetarian and/or vegan athletes choose to supplement up to 3 grams of carnitine per day. Research on the effects of this amino acid in individuals with heart concerns has focused on doses of 1-3 grams taken orally daily for up to 3 years. Supplementing with Acetyl-L-Carnitine, anywhere from 500 mg to 3 grams daily, can help boost energy levels as we age.
As always, since personal trainers may not have an additional national certification in nutrition or health coaching, we suggest speaking with a healthcare professional prior to beginning these or any other exercise supplements. Together, most clients will find they can develop a plan tailored to their workout and health-related needs.
References
webmd.com/vitamins-supplements/acetyl-l-carnitine
healthline.com/nutrition/l-carnitine
med.stanford.edu/news/all-news/2018/07/study-links-depression-to-low-blood-levels-of-acetyl-l-carnitine.html
bangkokhospital.com/en/bangkok/content/lcar-increase-muscle-reduce-fat
ods.od.nih.gov/factsheets/Carnitine-Consumer/
lpi.oregonstate.edu/mic/dietary-factors/L-carnitine
drrogerscenters.com/blogs/news/l-carnitine-benefits-dosage-side-effects-and-food-sources
study.com/academy/lesson/what-is-an-acetyl-group-definition-structure.html
pmc.ncbi.nlm.nih.gov/articles/PMC6498091/
sciencedirect.com/science/article/pii/S266713792500030X
