The Association of Diet and Physical Activity with Stroke Mortality Results from the Adventist Health Study-1

Stroke is one of the leading causes of death and disability, with major global public health implications. Stroke ranks No. 4 among all causes of death, behind heart disease, cancer, and chronic lower respiratory disease (CLRD). Stroke accounts for almost 1 of every 18 deaths in the United States. Women accounted for 60.6% of stroke deaths. Death certificate data show that the mean age at stroke death was 79.6 years; males had a younger mean age (76.3) than females. There is still a great scientific uncertainty among researchers and epidemiologists about the magnitude of any preventive effect, mechanisms of action and optimal diet and exercise prescription in relation to stroke reduction and prevention. Additionally, many of the studies investigating diet had several limitations since their results were based on crude assessments of diet and limited adjustments for confounding factors. Similarly, controversy regarding physical activity type, intensity and amount of time spent exist in relation to stroke mortality. This dissertation examined the independent effect of physical activity and the consumption of fruits/vegetables on stroke mortality, with a newly appreciated connection specific to fresh/raw and processed fruits, using data from the Adventist Health Study-1 (AHS-1). In the study, a cohort of 34,198 non-Hispanic whites, aged 25- 100, was followed from 1976 to 1988; of these, total of 434 fatal strokes were identified by record linkage with the California death certificate files and the National Death Index. The association between the main effects and stroke mortality was examined by Cox proportional hazard regression analysis using SAS 9.2 (SAS Institute Inc., Cary, NC, USA). The results from the first sub-study show that compared to very low fresh fruit intake (\u3c 3 times/week), consumption of fresh fruits \u3e 2 times/day was inversely associated with stroke mortality hazard ratio (HR, 0.48; 95% Cl: 0.25, 0.91, p-trend = 0.032) after important risk factors. In the second sub-study, all categories (high, middle, and low) of physical activity (PA) compared to none and/or slight PA showed a protective effect, with the middle category being the most protective (HR: 0.64, 95% Cl: 0.47,0.86) after adjustment for important risk factors. Our study results suggest an inverse association between fresh fruit/vegetable intake and physical activity with stroke mortality in this population