L-carnitine and its Derivatives

February 21, 2012 By

By: David Miller, BSc, N.D., NHP Scientific Regulatory Associate
February 21, 2011

The recent revisions to the status of Levocarnitine in the Canadian regulatory environment (http://www.gazette.gc.ca/rp-pr/p2/2011/2011-12-07/html/sor-dors275-eng.html) have exciting implications for integrative health care practitioners, industry, and the public at large.

Levocarnitine can be synthesized from lysine and methionine in the kidney, liver and brain, and 75% of carnitine stores are obtained from the diet (Flanagan et al., 2010). Skeletal and cardiac muscle have the highest concentrations in the body, but these tissues are incapable of synthesis, and so must acquire carnitine from the plasma (Flanagan et al., 2010).

Carnitine facilitates the transport of fatty acids into the mitochondria for the process of beta-oxidation (Evans and Fornasini, 2003) and subsequent production of Acetyl-CoA, a substrate of the citric acid cycle that generates energy in the form of adenosine tri-phosphate (ATP).

Carnitine influences the metabolism of carbohydrates and disorders of carnitine metabolism are associated with processes involved in diabetes, trauma, malnutrition, obesity, fasting, and other endocrine disorders (Flanagan et al., 2010).

L-carnitine has been evaluated in pre-clinical and clinical studies involving diabetes, sepsis, wound healing, neuroprotection and dementia, cardiovascular disease, aging and bone loss, dry eye and retinal disorders (Flanagan et al., 2010). However, when the general associations of weight loss and energy are associated with any nutritional supplement, there follows excitement and scrutiny.

From a clinical perspective, the best supportive evidence for the application of carnitine pertains to cardiovascular, cognitive health, and diabetes. Carnitine concentration in heart muscle is 4.2 mmol/g of tissue, accumulating against a 60-fold concentration gradient to a level approximately 3 times higher than skeletal muscle, where 98% of the body’s stores of carnitine are (Lango et al., 2001). Clinical studies have shown increases in claudication distance and decreases in mortality and circulatory failure in congestive heart failure, as well as decreased left ventricular diameter (Lango et al., 2001). L-carnitine derivatives have also exhibited clinical evidence of improved heart function (Lango et al., 2001).

Acetyl-L-carnitine (ALC) has been used in Alzheimer’s patients with promising results that showed improvements in commonly-used endpoints used to evaluate cognitive function (Altern Med Rev, 2010). Mood disorders and depression are another area of study, although these conditions should only be treated under the guidance of a well-informed health care practitioner.

Diabetes is a common condition seen in clinical practice with a growing prevalence in the population. ALC has been shown to be deficient in diabetics (Sima et al., 2005). Diabetic polyneuropathy is a late complication of diabetes that has been treated with promising results by ALC in clinical trials (Sima et al., 2005), with results showing increased nerve regeneration and vibration sense.

As a consumer and a health care practitioner, it’s great to see l-carnitine back on the shelf again.

In Good Health,

References:

  1. Acetyl-L-carnitine. Monograph. Altern Med Rev. 2010 Apr;15(1):76-83.
  2. Evans AM, Fornasini G. Pharmacokinetics of L-carnitine. Clin Pharmacokinet 2003;42:941­-67.
  3. Flanagan JL, Simmons PA, Vehige J, Willcox MD, Garrett Q. Role of carnitine in disease. Nutr Metab (Lond). 2010 Apr 16;7:30.
  4. Lango R, Smolenski RT, Narkiewicz M, Suchorzewska J, Lysiak-Szydlowska W. Influence of L-carnitine and its derivatives on myocardial metabolism and function in ischemic heart disease and during cardiopulmonary bypass. Cardiovasc Res. 2001 Jul;51(1):21-9.

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