Exercise-Supplement Combo May Help a Failing Heart
March 1, 2000 (Minneapolis) -- In a new study, researchers say that people
with heart failure might benefit from a combination of exercise and the dietary
supplement arginine to improve blood flow to the heart and the rest of the
body. But other heart experts warn that the findings are inconclusive.
Other recent research has shown that heart failure may be a disorder that
affects the entire body, rather than just a problem with the heart. Earlier
studies have shown, for example, that people with heart failure have
alterations in muscle metabolism that contribute to their inability to
Although earlier studies have shown that an enlargement of blood vessels,
allowing increased blood flow, resulted with just exercise and with arginine
alone, the authors of a study published in today's issue of the Journal of
the American College of Cardiology wanted to determine if a combination of
both might lead to greater benefits.
The preliminary trial involved 40 men 70 years or younger, all with heart
failure. Each did handgrip exercises six times a week and/or took the
supplement L-arginine three times a day. The researchers found that the
combination of regular exercise and the over-the-counter dietary supplement led
to a greater enlargement of blood vessels than either therapy alone.
Rainer Hambrecht, MD, an author of the study, says that exercise and
arginine together seem to significantly improve the ability of the blood
vessels to supply oxygen and nutrients to the cells of the body, including the
heart. Hambrecht is with the University of Leipzig Heart Center in Germany.
Heart specialists who spoke with WebMD were unanimous in their opinion that
the results are inconclusive and were quick to point out the study's
"[Similar] trials with as many as 500 patients have shown opposite
results," Andrew L. Smith, MD, tells WebMD. "It would be a huge leap to
suggest that there are implications [for the patient] from a trial of 40
people." Smith is assistant professor of medicine in the Division of
Cardiology and medical director for the Congestive Heart Failure Program at
Emory University School of Medicine in Atlanta.
"There are weaknesses in this study," Steven Almany, MD, tells
WebMD. He points out that the study participants were healthier than those
doctors usually see, and that the researchers looked only at arm exercises.
"Does that mean that exercising the leg or heart should show similar
responses? We just don't know that," he says. Almany, medical director in
the department of cardiology at William Beaumont Hospital in Royal Oak, Mich.,
was not involved in the study.
Smith says that though the new data are interesting, larger-scale trials are
needed. "While [arginine] is a natural substance, we know that certain
natural substances can be harmful," he says. "There is a concern in the
heart failure community that patients are taking [over-the-counter] medications
that may have harmful effects."
But Almany has no problem giving arginine to his patients. "Right now,
if a patient asked me about taking arginine, I would have no [qualms] with
it," he says. Still, he adds, "This is not a definitive study, and we
need to take it further. One thing we do know is that exercise is beneficial
for people with heart failure. That's been proven."