Coronary artery disease (CAD) is common and multifactorial. Members of the Church of Jesus Christ of Latter-day Saints (LDS, or Mormons) in Utah may have lower cardiac mortality than other Utahns and the US population. Although the LDS proscription of smoking likely contributes to lower cardiac risk, it is unknown whether other shared behaviors also contribute. This study evaluated potential CAD-associated effects of fasting. Patients (n(1) = 4,629) enrolled in the Intermountain Heart Collaborative Study registry (1994 to 2002) were evaluated for the association of religious preference with CAD diagnosis (> or = 70% coronary stenosis using angiography) or no CAD (normal coronaries, <10% stenosis). Consequently, another set of patients (n(2) = 448) were surveyed (2004 to 2006) for the association of behavioral factors with CAD, with routine fasting (i.e., abstinence from food and drink) as the primary variable. Secondary survey measures included proscription of alcohol, tea, and coffee; social support; and religious worship patterns. In population 1 (initial), 61% of LDS and 66% of all others had CAD (adjusted [including for smoking] odds ratio [OR] 0.81, p = 0.009). In population 2 (survey), fasting was associated with lower risk of CAD (64% vs 76% CAD; OR 0.55, 95% confidence interval 0.35 to 0.87, p = 0.010), and this remained after adjustment for traditional risk factors (OR 0.46, 95% confidence interval 0.27 to 0.81, p = 0.007). Fasting was also associated with lower diabetes prevalence (p = 0.048). In regression models entering other secondary behavioral measures, fasting remained significant with a similar effect size. In conclusion, not only proscription of tobacco, but also routine periodic fasting was associated with lower risk of CAD.