Does the periodic vegetarianism of Greek Orthodox Christians benefit blood pressure?

Objective The Greek Orthodox Christian (GOC) diet is a periodic vegetarian-type diet that shares all the characteristics of the Mediterranean diet. No study to date has investigated its impact on blood pressure (BP). Methods Thirty-eight devout Orthodox Christian fasters and 29 matched controls living in Crete, Greece, were followed for 1 year during 2001. BP data were gathered before (pre) and near completion (end) of the three major fasting periods of the Orthodox Christian calendar [Christmas (40 days)–Easter (48 days)–Assumption (15 days)] along with other information on their dietary and lifestyle habits, body measurements and blood samples. Results Throughout the study fasters had higher mean SBP and DBP than controls. No fasting period had a significant BP lowering effect on fasters. Fastersʹ prevalence of end-Christmas and end-Lent high–normal BP was significantly higher than that of the controlsʹ, while it was reduced during the Assumption and reached the very low levels of controlsʹ. On the whole, compared to controls, fasters increased their fiber, magnesium and fruit and vegetable consumption during the fasting periods and decreased their sodium and calcium intake. BMI and blood lipids were significantly associated with SBP/DBP at almost all measurements. Conclusion Religious adherence to a periodic vegetarian Mediterranean-style diet does not have an observable effect on BP. Further research is needed in order to establish conclusive evidence.