Canadian AIDS Treatment Information Exchange: TreatmentUpdate 47 - Volume 4, No. 7 - February 1994
Sean Hosein

* SOURCES

A rule of thumb, "foods of animal origin contain substantial amounts of carnitine, whereas foods of plant origin contain very little", says biophysicist Chester Myers. Red meats are the richest source of carnitine. In comparison, milk, chicken and fish contain 10 to 40 times less carnitine than red meats. Although asparagus, avocados and peanut butter contain more carnitine than most fruits and vegetables, the amount of carnitine in those fruits/vegetables is very, very small. For the average healthy person in North America and the EC "about 70 to 80% of carnitine in food is absorbed."

* SOURCES IN THE BODY

The body (liver, kidneys and brain) makes carnitine using the amino acids lysine and methionine along with vitamin C and other substances. Carnitine is stored in the muscles and the concentration of carnitine in the muscles is greater than in the blood.

* EFFECT OF HIV INFECTION

As a result of changes in energy cycles, some people with HIV infection may not be able to make enough carnitine. Researchers have reported the amino acids used to make carnitine may come under increased demand for making other products. As well, the amino acids cysteine and methionine may be damaged (oxidized) to the point where they cannot be reused to make carnitine. Patients on kidney dialysis may need extra carnitine (personal communication, C. Myers).

* TRIGLYCERIDES AND FATTY ACIDS

To make fats and lipids the body uses fatty acids and substances called triglycerides (TG). In people with HIV infection, blood levels of TG increase as the efficiency and effectiveness of the immune system declines. Researchers are not sure why this happens but here are three possible reasons people with HIV have high levels of TG:

- camitine deficiency: the "main symptoms of carnitine deficiency are high blood levels of TG and muscle fatigue.

- abnormal energy cycles: in some people with HIV infection the body breaks down fats to form fatty acids and then rebuilds fats using these fatty acids. This recycling uses up energy and protein. Thus the body uses up protein and builds up stores of fat. As protein is needed by the immune system, this loss of protein may, in the long term, affect the functioning of the immune system.

- drug toxicity: people who use the following drugs may need extra carnitine: sulfadiazine, pyrimethamine, valproic acid, pivampicillin and ipecac syrup (emetine).

* DIETARY NOTES

For some people with HIV/AIDS, muscle fatigue and high blood levels of TG may be caused by a deficiency of carnitine. Readers should note that there are also other causes of muscle fatigue. To correct the "errors" in the way HIV infection has altered energy cycles, people with HIV/AIDS may make some changes to their diet adding extra

- protein: (milk and egg proteins are easier to digest than soy proteins) which will provide the amino acid cysteine. This amino acid is used to make antioxidant enzymes that protect cells from toxic substances.

- fatty acids: used as fuels and also to make hormones, some of which affect the immune system. Good sources of fatty acids include olive and evening primrose oil. Supplements of medium-chain triglycerides are also another source of energy and the body does not need carnitine to use this.

- carnitine: supplements of carnitine may be necessary. In TreatmentUpdate 46, we reported that researchers used 6 grams/day of carnitine in their study. Doctors do not yet know the best dose of carnitine to use in a regimen of supplements for people with HIV/AIDS. Chester Myers suggests 1 gram daily may be useful. Carnitine is a licensed drug in the USA (sold by prescription as Carnitor(R) and sold in Italy by Sigma Tau. As well, some health food stores and buyers' clubs also sell carnitine.

ACKNOWLEDGMENTS:

1. We would like to thank C. Myers PhD for his review, research, support and comments which were all very helpful in writing this report on carnitine.

REFERENCES:

1. Myers CD. Carnitine. Brochure 1993 (available at CATIE).

2. carnitine deficiency. Editorial. Lancet 1990;335:631-633.

3. Sekas G and Paul H. Hyperammonemia and carnitine deficiency in a patient receiving sulfadiazine and pyrimethamine. American Journal of Medicine 1993;95 :112-113.

4. Di Simone C, Tzantzoglu S, Famularo G, et al. High dose L- carnitine improves immunologic and metabolic parameters in AIDS patients. Immunopharmacology and Immunotoxicology 1993;15(1): 1-12

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Copyright © 1994 - TreatmentUpdate. Reproduced with permission. Reproduction of this article (other than one copy for personal reference) must be cleared through the Editor, The Canadian AIDS Treatment Information Exchange, 555 Richmond St. West, Suite 505, Box 1104, Toronto, ON, M5V 3B1 • Phone: 416-203-7122 • Toll Free: 1-800-263-1638 • Fax: 416-203-8284  http://www.catie.ca