The company referenced at least five peer-reviewed studies that indicated energy-boosting benefits in exercise resistance and recovery and vascular benefits in healthy populations.
Another two (Spiering, B. et al. 2007; Rubin, M.R. et al. 2001) showed that L-carnitine could be effective at lower doses than the 3-4g per day referenced by the Times that were linked to diarrhea and nausea and were therefore not necessarily pertinent.
“Recent scientific studies have shown that people can realize benefits from L-Carnitine when it is taken in lower levels of only 1-2 grams,” said Michael DeGennaro, Lonza vice-president of sales and marketing – human nutrition.
The professor in question, Dr Ziv Haskal, a specialist in radiology and surgery at the University of Maryland Medical Center in Baltimore, told The LA Times L-carnitine was “another fad supplement”.
Beyond a fad
DeGennaro pointed to L-carnitine’s 25-year on-market history that began with an infant formula debut in 1984.
“L-Carnitine continues to grow in its applications, such as food and beverages, and supplements,” he said. “It has also been approved for certain pharmaceutical applications. The evidence supports that it will continue to be taken by individuals for years to come.”
The company said it backed the scientific process and would, “continue to look to scientific evidence as the basis for our business.”
The five studies referenced by Lonza were Volek, J. et al. 2002; Kraemer, W. et al. 2003; Kraemer, W et al. 2006; Spiering, B. et al. 2008; Volek, J. et al. 2008.
Dr Haskal asserted that the energy-boosting results of studies conducted on those with vascular and heart disease, could not necessarily be extrapolated to healthier people after he conducted a review for the American College of Cardiology Foundation and the American Heart Association.
L-carnitine became popular in energy drinks and dietary supplements in the 1990s after studies indicated its energy-giving benefits.
It ferries fatty acids into the cells, but its exact mechanism is not completely understood, hence the ambiguity among scientists about its role and the benefits of supplementation for a molecule the body makes naturally at certain levels.