This study was published in Circulation 1988 Vol 77, 767-773
Study title and authors:
Increases in walking distance in patients with peripheral vascular disease treated with L-carnitine: a double-blind, cross-over study
G Brevetti, M Chiariello, G Ferulano, A Policicchio, E Nevola, A Rossini, T Attisano, G Ambrosio, N Siliprandi and C Angelini
Department of Medicine, Second Medical School, University of Naples, Italy.
This study can be accessed at: http://circ.ahajournals.org/content/77/4/767.full.pdf+html
The study evaluated the effects of L-carnitine in 20 patients with peripheral vascular disease.
The patients were randomly assigned to receive placebo or L- carnitine for a period of 3 weeks and were then crossed over to the other treatment for an additional 3 weeks. The effect on walking distance at the end of each treatment period was measured by treadmill test.
The study found:
(a) When assigned to placebo walking distance by patients was 174 meters.
(b) When assigned to L-carnitine walking distance by patients was 306 meters.
(c) Patients assigned to L-carnitine had fewer symptoms of "pins and needles", were less tired, and had less pain during walking compared to patients on placebo.
(d) Patients assigned to placebo had more lactate in their blood after exercise compared to patients assigned to L-carnitine. (Exccess lactate may lead to a deficiency in the amount of oxygen reaching body tissues).
The study demonstrated that L-carnitine, improved the walking capacity of patients with intermittent claudication.
Animal products like meat, fish, poultry, and milk are the best sources of carnitine. In general, the redder the meat, the higher its carnitine content. E.g. In 4 ounces of Beef steak there are 56-162 milligrams of carnitine, 1 cup of whole milk yields 8 milligams and chicken breast provides 3-5 milligams per 4 ounces. Conversely plant foods are poor providers of carnitine; 2 slices of whole-wheat bread only have 0.2 milligrams and 1/2 cup of asparagus yields just 0.1 milligrams.
