Introduction:

1. 3RD CONFERENCE ON HEALTH TRANSFORMATION IN CENTRAL EUROPE AFTER 1990: A THIRD LOOK Is the dramatic decline in cardiovascular diseases in Central Europe (Czech Republic, Slovakia, Poland) mainly due to dietary changes? Warsaw, October 29-30, 2001 Provadia rural district Dolen Chiflik rural district Could seasonal deficits in protective foods be contributing to high stroke incidence in Bulgaria?The Varna Diet and Stroke Study. Powles J 1, Kirov P 2*, Feschieva N 3, Stanoev M 3, Dokova K 3, O’Connell M 4, Sanz A 5 (*presenter) Varna Diet and Stroke Study, c/- Department of Social Medicine, Marin Drinov 52, 9002 Varna, Bulgaria. http://www.medinfo.cam.ac.uk/com_med/varna/stroke/index.htm • 1 Department of Public Health and Primary Care, Institute of Public Health, Cambridge CB2 2SR, UK, 2 Clinic of Neurology, Intensive Care Stroke Unit, University Hospital, Varna, Bulgaria, 3 Varna Diet and Stroke Study, c/- Department of Social Medicine, Marin Drinov 52, 9002 Varna, Bulgaria, 4 MRC Human Nutrition Research,Elsie Widdowson Laboratory, Cambridge, UK,5 Dept de Medicina y Salud Publica, Universidad del Pais, Vasco,Bilbao, Spain. Introduction: East / west gradients for deaths attributed to stroke tend to be greater than those for coronary heart disease and high rates in the east are inadequately explained by published data on blood pressure distributions and smoking prevalence. Fresh fruit and vegetable consumption in winter/spring has been very low in the East, even in countries such as Bulgaria and Hungary which have had high consumption levels in summer/autumn. • Conclusions • This developmental study has confirmed a close ecological association between the fall in plasma vitamin C in winter and the incidence of stroke. • The hypothesis that cerebrovascular disease is accelerated by the cumulative effects of very low intakes of protective constituents of plant foods during each winter/spring deserves to be tested by large scale cohort studies in populations heterogeneous for this exposure and for stroke risk. Methods: Stroke incidence study. A ‘hot pursuit’ stroke registry was established in Primorski district of the city of Varna and in 2 rural districts (Dolen Chiflik and Provadia). The study registrar maintained close personal and telephone contact with dense networks of notifiers – especially in primary care in the ambulance service. Suspected eligible strokes were assessed by study neurologists within a median (interquartile range) of 8 (4-31) days. First in lifetime strokes at ages 45 to 84 in year beginning 1/5/2000, form the basis of this report. Methods: Diet study Volunteers aged 45 to 74 were quota sampled from the patients of general practitioners (n = 37, 38, 44 and 40 for rural and urban males and females respectively). Volunteers kept diet diaries for one week in winter and one week in the following summer and gave 2 24 hr urine collections (PABA validated for completeness) and blood in each season. Plasma vitamin C is used as a biomarker for fresh fruit and vegetables. • Results: • Stroke incidence varied markedly (chart right) with very high rates among rural males whilst rates among urban females were comparable to western rates. • There was a close association between stroke incidence and the level of plasma vitamin C in winter. Plasma vitamin Cs were uniformly high in summer. • Sodium consumption was very high (around 300 mmol/d in the males) and showed a limited association with stroke risk. • Preliminary analyses of group means for urinary potassium, plasma fibrinogen and plasma folate and homocysteine show them to be unrelated, ecologically, to stroke incidence. • Incidence was modestly higher in November to April than in May to November (193 cases versus 158). RM, UM, RF and UF = rural males, urban males, rural females and urban females Scatterplots of plasma vitamin C concentrations in winter versus summer