Dietary Habits and Lifestyle Factors Associated with Vascular Diseases: A Case–Control Study

Background/Objectives: Vascular diseases remain a leading cause of global mortality, yet the dietary and lifestyle factors that contribute to them are not fully understood in Central Anatolian populations. This study aimed to quantify the dietary and lifestyle predictors of vascular disease status in a case–control cohort from a tertiary care setting in Yozgat province. Methods: A total of 1452 adults were enrolled from Yozgat Bozok University Research Hospital: Cardiovascular Surgery (CVS; cases, n = 720) and Primary Care (PC; controls, n = 732). All participants completed a 43-item questionnaire on diet, lifestyle, and sociodemographic characteristics. Binary logistic regression was used to identify independent predictors of case status, with age, sex, education, and income being included in the model. Results: Chronic comorbidities were present in 33.9% of the control group and 80.3% of the case group. Use of olive oil was most strongly associated with control status (odds ratio [OR] = 0.17; 95% confidence interval [CI]: 0.11–0.27), followed by use of butter (OR = 0.25). Paradoxically, fast food (OR = 0.24) and junk food (OR = 0.31) consumption were more frequent among controls. The use of sunflower oil (OR = 2.30), diabetes (OR = 5.22), and elevated serum ferritin (OR = 1.04 per 10 ng/mL) independently predicted a higher likelihood of being in the case group. The model explained 54.8% of the variance (Nagelkerke R2 = 0.548). Conclusions: The apparently higher prevalence of unhealthy dietary behaviours among controls is most plausibly attributed to post-diagnosis dietary modification among cases (an ‘illness effect’), underscoring the window for intervention before disease onset. As this case–control design precludes causal inference, these associations are hypothesis-generating. Promoting olive oil and reducing sunflower oil represent practical, culturally feasible dietary targets for cardiovascular risk counselling in Central Anatolia, pending prospective confirmation.