Swiss ingredient manufacturer Lonza, which markets a branded l-carnitine called Carnipure, backed the review together with researchers from Tufts University in Boston.
They examined human clinical trials from the last few decades where l-carnitine supplementation was used in post-exercise recovery and found that L-carnitine supplementation was linked to reduced muscle soreness and injury, as well as increased blood flow, contributing to recovery.
The report was published in the journal Nutrients.
Excluded from the review were trials where l-carnitine was given in combination with other products (multi-ingredient supplements), an outcome not related to post-exercise recovery, or written in languages other than English, German or French.
Benefits for an aging population
L-carnitine is commonly found in sports nutrition supplements from pre-workout to post-workout recovery powders.
But Lonza has been pushing for more research and marketing to promote it as a supplement for older adults.
“While previous research has mainly focused on the effects of supplementation in athletes, we also reviewed the current research in a wider demographic that includes older adults,” said Dr. Aouatef Bellamine, a co-author of the study and senior scientific manager of consumer health and nutrition at Lonza.
“In particular, with a growing number of elderly subjects engaged in moderate exercise, the role of L-Carnitine in helping to improve quality of life among this demographic will continue to gain importance.”
Lonza’s hopes of an L-carnitine health claim dashed by EFSA
Lonza’s assertion that L-carnitine contributes to normal lipid metabolism was rejected by EU authorities, who could not find a link between the supplement and a ‘beneficial physiological effect.’ (Originally published 1/17/2018)
Last year, the company conducted a trial together with Tufts, Georgetown University, Paraxel and KGK Synergize, in which L-carnitine fared better than placebo in promoting muscle growth in 42 participants aged 55 to 70.
Dr. Bellamine added: “The results of this review could therefore be taken into consideration when planning the diets of younger, active consumers, while also helping to shape the future direction of research, to explore in greater depth the role L-Carnitine supplementation can play alongside exercise in mitigating age-related muscle degradation.”
L-Carnitine Supplementation in Recovery After Exercise
Nutrients 2018, 10(3), 349; doi:10.3390/nu10030349
Authors: Fielding R, Riede L, Lugo JP, Bellamine A