In order to keep the circulatory system, you would want to keep a low-fat diet that consists of vegetables, grains and fruits. You also want to avoid smoking as well as saturated fats and trans fats. It is also recommended to avoid drinking alcohol. Relaxing to reduce stress is also a recommendation to keep in mind for the circulatory system. Stay away from foods with sugars and in general just unhealthy foods. It is also vital to get between 7-8 hours of sleep a night.
https://www.healthline.com/health/circulatory-system-diseases#prevention