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Levels of this vitamin-like nutrient decline as we age
by Carol Ferguson
Manufactured from the amino acids lysine and methionine,
L-carnitine helps transport long-chain fatty acids across
the mitochondrial membrane of cells, where they’re
metabolized as fuel. Because it’s the only substance
that can perform this vital task, we all need plenty
of carnitine, which is available in meat and in supplements.
While outright deficiency is uncommon in well-nourished
populations, vegetarians, older individuals, and those
who have kidney and liver disease or who take anticonvulsant
medications may need more of this vitamin-like nutrient
than their diets provide.
Cardiovascular Health
The heart gets 60 percent of its fuel from fat, making
L-carnitine important for cardiovascular health. By
enhancing fatty acid metabolism, carnitine prevents
the buildup of toxic fat metabolites.
Numerous double-blind, placebo-controlled studies find
this substance effective in treating angina, a crushing
sensation in the chest caused by inadequate blood flow
to the heart muscle. “Having enough carnitine
in the tissue to metabolize fatty acids efficiently
lets the heart do more with less oxygen,” explains
cardiologist Stephen T. Sinatra, MD.
Since physical exertion tends to trigger angina, exercise
studies are a useful way to explore L-carnitine’s
effects. Among 200 angina patients 40 to 65 years old,
those taking L-carnitine showed better cardiac performance,
as well as improved quality of life. Surprisingly, those
with the most compromised heart function experienced
the greatest improvement with L-carnitine, which also
improves exercise duration and oxygen consumption in
research with heart failure patients.
In peripheral vascular disease (painful leg cramping
in patients with arteriosclerosis), “no pharmaceutical
drug has been observed to convey significant benefit,”
says cardiologist Seth J. Baum, MD. “What does
work quite well, however, is the supplement L-carnitine.”
Among obese individuals with insulin resistance, L-carnitine
appears to improve vascular function, as reported in
investigations of leg blood flow. In a study at Indiana
University School of Medicine, researchers found that
increasing L-carnitine levels may delay cardiovascular
disease progression in obese subjects.
Ongoing European investigations suggest that carnitine,
administered early in a heart attack, can slow the advancement
of heart disease. L-carnitine also showed protective
effects in a double-blind study of arrhythmia patients.
“Perhaps the most outstanding aspect of the use
of L-carnitine supplementation in cardiovascular conditions
has been its ability to assist coenzyme Q10 and D-ribose
in reducing the mortality from end-stage congestive
heart failure,” adds Dr. Sinatra. Compared to
healthy individuals, heart failure patients have significantly
lower carnitine concentrations in their heart muscle.
The good news is that recent research suggests that
carnitine supplementation can reverse this dangerous
trend.
Using L-carnitine
Red meat is the richest food source of L-carnitine,
and Dr. Baum recommends that omnivores choose organic
sources. “I am convinced that the less opportunity
man has to impose his artificial imprint [antibiotics
and hormones] the better off food is,” he adds.
L-carnitine is also a safe supplement; just don’t
take it with the medication pentylenetetrazol. For aging
and overall heart protection, Dr. Sinatra recommends
250 to 750 mg of L-carnitine, along with CoQ10, D-ribose,
magnesium, and fish oil daily. Angina and arrhythmia
patients can take 1,000 to 2,000 mg of L-carnitine daily.
For congestive heart failure, Dr. Sinatra suggests 2,000
to 3,500 mg daily, depending on that condition’s
severity. TFL
Selected Sources
- Age Strong, Live Long by Seth J. Baum, MD ($12.95,
Desert Spring, 2005)
-“Cardiac Carnitine Leakage Is Promoted by Cardiomyopathy”
by H. Baker et al., Nutrition, 3/05
-“L-Carnitine May Attenuate Free Fatty Acid-Induced
Endothelial Dysfunction” by S. S. Shankar et al.,
Ann N Y Acad Sci, 11/04
- The Sinatra Solution by Stephen T. Sinatra, MD, FACC
($24.95, Basic Health, 2005)
-“Therapeutic Effects of L-Carnitine . . . on
Cardiovascular Diseases: A Review” by R. Ferrari
et al., Ann N Y Acad Sci, 11/04
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