Taurine Proves Heart-Worthy in Smokers 28055

Taurine Proves Heart-Worthy in Smokers

DUBLIN, Ireland--New research highlighted the semi-essentialamino acid, taurine, as a possible deterrent of cigarette smoke-inducedendothelial dysfunction, a precursor to atherosclerosis. Appearing in the Jan. 6rapid access issue of Circulation: Journal of the American Heart Association(AHA) (www.circulationaha.org), thestudy indicated that taurine supplementation worked even better than vitamin Cin improving impaired flow-mediated dilation (FMD), an effect that may be due tochronic cigarette smoking impairing the activity of endothelial-derived nitricoxide.

Lead author David Bouchier-Hayes, M.D., and colleagues from the Royal Collegeof Surgeons in Dublin, Ireland, noted nitric oxide activity is critical in manyheart-health processes, including platelet aggregation, vascular smooth muscleproliferation and oxidative modification of LDL cholesterol. FMD, a nitricoxide-mediated response, has been shown to appear in the brachial arteries ofyoung, otherwise healthy, cigarette smokers, according to the study'sresearchers.

"When blood vessels are exposed to cigarette smoke, it causes thevessels to behave like a rigid pipe rather than a flexible tube," Bouchier-Hayesstated in an AHA press release, "thus the vessels can't dilate in responseto increased blood flow. We're not trying to find a therapeutic treatment forsmoking, because we believe the best therapy for smokers is to stop smoking.Nonetheless, smokers provide a good clinical model for treatment of endothelialdysfunction."

The study involved 15 healthy smokers (20 to 37 years old who smoked at leasttwo packs per day) and 15 nonsmokers (21 to 35 years old). All volunteers werenormotensive and had no history of hyperlipidemia. For five days, smokers weregiven 2 g/d of vitamin C (supplied by Basel, Switzerland-based RochePharmaceuticals), followed by a two-week washout period, and were then given 1.5g/d of taurine (provided by Hauppauge, N.Y.-based Twinlab).

Using duplex ultrasonography, researchers assessed the effect of FMD onbrachial artery diameter at baseline in both nonsmokers and smokers, with FMDsignificantly impaired in the latter. Vitamin C supplementation had asignificant effect on the smokers' FMD, with arterial diameter increasingapproximately .12 mm; however, FMD was not restored to the level seen in thenonsmoking control group. Conversely, taurine supplementation was found to notonly increase arterial diameter approximately .37 mm, but FMD was restored tolevels found in the control group.

The researchers reported that taurine, which appears to be nontoxic, alreadyis used clinically in similar or greater daily doses in patients with diabetesmellitus and congestive heart failure. Also, in a worldwide epidemiologicalstudy on dietary prevention and cardiovascular disease (the CardiovascularDiseases and Alimentary Comparison Study), 100 g/d of fish was found to reducethe risk of coronary artery disease at the same level as seen in the Japanesepopulation. "The dose of taurine used in the present study is equivalent tothat found in 100 g of fresh fish," Bouchier-Hayes et al noted.