RECENTLY released research about a compound found in meat and nutrition supplements completely contradicts previously reported research suggesting that the compound contributes to cardiovascular events.
Indeed, the new research, in a report in Mayo Clinic Proceedings, concluded that the compound L-carnitine "significantly improves" cardiac health, especially in patients who have suffered strokes.
L-carnitine is commonly found in energy drinks, beans, nuts, produce and red meat such as beef and pork, and it helps the body transport fatty acids into cells to be used as energy.
However, researchers at the Cleveland Clinic who examined the medical records of both meat eaters and vegetarians undergoing cardiac evaluations determined that those patients who consumed high levels of L-carnitine were more likely to develop atherosclerosis and suffer heart attacks, strokes and death (Feedstuffs, April 15).
The Cleveland researchers suggested that individuals should moderate their consumption of meat and reduce their consumption of energy drinks.
The investigators in the Mayo report, however, have associated L-carnitine with "a significant reduction" in deaths from all causes and "a highly significant reduction" in cardiac events following heart attacks.
Cardiovascular disease is the leading cause of death in the U.S., and although a number of therapies have been developed in recent years to markedly improve life expectancy, adverse cardiovascular events such as angina attacks and ventricular arrhythmias continue to occur quite frequently after heart attacks, according to the Mayo report.
It's known that during ischemic events, i.e., a disruption in blood flow, L-carnitine levels are depleted, the report says.
Accordingly, the investigators said they wanted to determine the effect of targeting cardiac metabolic pathways using L-carnitine to improve fatty acid levels and glucose oxidation in patients.
They explained that they conducted a meta-analysis of studies that have been published on this concept over several decades, comparing the impact of L-carnitine and a placebo in patients who had experienced acute heart attacks.
L-carnitine's role in treating cardiovascular disease was first reported in the late 1970s, they noted.
The investigators said their literature search yielded 153 relevant studies, and 13 of them, published from 1989 to 2007, were deemed eligible for comparing trials using L-carnitine and placebos in settings involving acute heart attacks.
The trials involved 3,629 patients, 250 of whom died, 220 of whom experienced another heart failure and 38 of whom had recurrent heart attacks. The investigators said L-carnitine was associated with:
* A significant 27% decrease in all-cause mortality;
* A significant 40% decrease in angina development;
* A highly significant 65% decrease in ventricular arrhythmias, and
* A decrease in the size of blood flow disruptions.
There were numerically fewer heart failures and heart attack recurrences in patients on L-carnitine regimens, the investigators said.
Lead author James J. DiNicolantonio, a pharmacologist with Wegmans Pharmacy in Ithaca, N.Y., reiterated that although therapies are available to improve clinical outcomes for heart patients, adverse cardiovascular events still strike after heart attacks, but "one promising therapy" for cardiac health involves using L-carnitine to improve fatty acid levels and glucose oxidation.
The investigators said they agree that the overall results of their study support the potential use of L-carnitine in preventing and treating heart attacks and secondary events, although they recommended that a large trial be conducted to confirm their expectations.
However, DiNicolantonio noted that L-carnitine is proven to be safe and is readily available in certain foods and over the counter in certain supplements. Accordingly, he said L-carnitine therapy "can already be considered in patients with high-risk or persistent (cardiovascular issues) who cannot tolerate (certain other treatments) considering L-carnitine's excellent safety profile and low cost."
The investigators noted that their findings contradict those of the Cleveland research, but they said the main work of that research was in animals "and, unlike our study, lacked hard outcomes."
Unfortunately, beef and pork producer sources pointed out, the Mayo report did not receive the publicity that the Cleveland research was given.