Abou-agag LH, Khoo NK, Binsack R, White CR, Darley-Usmar V, Grenett HE, Booyse FM, Digerness SB, Zhou F, Parks DA. Evidence of cardiovascular protection by moderate alcohol: Role of nitric oxide. Free Radic Biol Med 2005;39:540-548.
Moderate alcohol increases vascular NO.
Akishita M, Hashimoto M, Ohike Y, Ogawa S, Iijima K, Eto M, Ouchy Y. Low testosterone level is an independent determinant of endothelial dysfunction in men. Hypertens Res 2007;30:1029-34.
187 men had measurement of flow-mediated vasodilation as a measurement of endothelial function and NO release. It was significantly correlated with total and free testosterone independent of age, BMI, hypertension, hyperlipidemia, and smoking (p< 0.01). This finding is consistent with the effect of castration on erectile function (Traish 2003) and T therapy on increasing penile NO (Garban).
Akkus E, Kadioglu A, Esen A, Doran S, Ergen A, Anafarta K, et al. Prevalence and Correlates of Erectile Dysfunction in Turkey: A Population-Based Study. European Urology 2002;41:298-304.
This large population study examined the factors related to ED in men over age 40. ED was decreased by two-thirds in moderately active men and by over 80% in active men. Use of alcohol was associated with almost a 60% reduction of ED.