Reserving judgement about L-arginine
Staying in Circulation
An HSI member named Kevin is wisely reserving his judgment about a recent study that hit close to home.
Kevin writes: “L-arginine has been linked to several deaths in a study conducted by Johns Hopkins. I am a 56-year-old male in good physical condition with no known heart disease and I take L-Arginine/Orthnine as part of my work out supplements. Am I at risk? The study cites the deaths were among a study population who had known heart disease.”
Kevin’s doctor would be the best one to assess his risk. But before he dials up his physician, there are some further details he needs to be aware of.
Flexible vessels
We’ve told you about the benefits of L-arginine in several previous e-Alerts and HSI Members Alerts.
L-arginine is an amino acid that’s been shown to reduce inflammation, repair skin and connective tissue, and regulate the thymus gland. L-arginine is also a precursor of nitric oxide, an essential compound and neurotransmitter that stimulates secretion of insulin and promotes blood circulation by dilating vessels.
The study that Kevin refers to was reported last month in the Journal of the American Medical Association. To determine if L-arginine reduces vascular stiffness, researchers at Johns Hopkins recruited more than 150 subjects who had experienced a heart attack. Half the group received nine grams of L-arginine each day, and half received a placebo.
During the six-month study period, six subjects in the L-arginine group died, so further enrollment in the study was discontinued. The Hopkins team also reported that, overall, vascular stiffness was apparently not improved.
On the plus side
Naturally, this study raises concerns, and anyone with a history of history of heart problems should talk with their doctor about further use of L-arginine.
But there are two key points to keep in mind about the study: 1) All of the subjects were heart attack patients, and 2) All of the subjects were using various prescription drugs considered standard post-heart attack therapy. In other words, there’s nothing in this study that would indicate that L-arginine use poses any danger for healthy subjects.
On the contrary, L-arginine (a natural component of meat, poultry, fish, nuts, whole-wheat and dairy products) has been shown to facilitate muscle metabolism by reducing body fat while increasing muscle mass.
And in the e-Alert “Sensitive Side” (3/29/05), I told you about a UK study that showed how L-arginine might significantly improve insulin sensitivity and lower systolic blood pressure in subjects with type 2 diabetes.
L-arginine may also help people who exercise overcome mental fatigue and physical exhaustion. So Kevin is probably on the right track with his L-arginine use in conjunction with his workout regimen. But just like anyone who uses dietary supplements, he should consult with his doctor or a healthcare specialist.
Sources:
“L-Arginine Therapy in Acute Myocardial Infarction” Journal of the American Medical Association, Vol. 295, No. 1, 1/4/06, jama.ama-assn.org
“Don’t Take L-Arginine for Heart Attack” Daniel DeNoon, WebMD Medical News, 1/3/06, webmd.com
