Smoking increases the risk for stroke by approximately 40% in men and 60% in women, and accounts for almost 21% of the global stroke burden. Cigarette smoking raises the blood fibrinogen concentration, enhances platelet aggregation, and increases the hematocrit level and blood viscosity. It is one of the most powerful risk factors that contributes to the development of large artery atherosclerosis throughout the body and may also contribute significantly to the development of aneurysms intracranially and systemically. Second-hand smoke may also increase the risk for stroke. Smoking cessation substantially decreases the risk for subsequent stroke in a remarkably short time and is particularly vital for patients who present with cerebral or retinal ischemic events. The risk for stroke decreases substantially each year after cessation of cigarette smoking, and by the end of 5 years, the risk is nearly that of a person who never smoked. The physician should review with the patient who smokes the benefits of quitting and the risk of continuing. Smoking or nicotine dependence centers have become increasingly sophisticated at assessing the nature and the severity of an individual’s dependence, determining which of several different strategies is most likely to succeed for a given patient’s situation and providing needed support. In general, a combination of counseling services and medical management is most effective. Medications including nicotine patches or nicotine replacement gum (initial dose depends on the number of cigarettes smoked per day), or nonnicotine medications including bupropion sustained release or varenicline may be useful smoking cessation aids unless contraindications exist.

Poor diet is one of the largest contributors to stroke burden: over 50% of strokes could eventually be eliminated if all people had a healthy, well-balanced diet.
Diet may help to prevent stroke in two ways: it can prevent the development and the progression of stroke risk factors, such as atherosclerosis, hypertension, hyperlipidemia, ischemic heart disease, and diabetes mellitus, and it can provide beneficial food components, such as fruits and vegetables, that can independently reduce the risk for stroke. In coronary atherosclerosis, existing evidence suggests that to stabilize or reverse atheroma, dietary intake of fat (especially saturated fat) must be reduced to less than 10% of the total caloric intake and cholesterol to less than 5 mg per day (major sources of saturated fatty acids and cholesterol are meat, eggs, and dairy products) through a very low-fat vegetarian diet. Such results have been associated with total serum cholesterol levels of or lower than 150 mg per dL. The same principles may also apply to carotid and other large-vessel atherosclerosis. However, randomized, controlled trials have not yet been reported, except with respect to coronary arthrosclerosis. There is also some evidence that eating fish or other plant-based sources of omega-3 fatty acids (flaxseed, soybeans, soybean oil, walnuts) more than 2 times per month and using reduced-fat milk (along with other appropriate dietary modifications) may reduce the risk for stroke although this evidence remains inconclusive. Restriction of dietary salt (to ˜5 g per day) or sodium intake (to ˜2 g per day) helps in the prevention and management of hypertension. In hot, humid climates, the reduction in dietary sodium should be modified to accommodate for the loss of sodium in such extreme conditions. In general, patients should be discouraged from consuming salt-rich foods or adding salt to already prepared foods. Ensuring an adequate intake of food rich in potassium, calcium, and magnesium may also help to keep the BP under control.

In a typical American diet, approximately 40% to 45% of the dietary caloric intake is in the form of fat (most of which is saturated fat), and the cholesterol intake is approximately 400 mg per day. The standard low-fat diet (see Appendix F-1) reduces fat consumption to approximately 30% of the dietary caloric intake (saturated fat constituting <10% of calories) and cholesterol consumption to approximately 300 mg. This diet is recommended as a minimal modification for general health reasons, even for individuals without atherosclerosis. It is recommended to match energy intake with energy needs.

An even more healthful alternative for the prevention of atherosclerosis in the general population and the diet that is strongly recommended for individuals with symptomatic or asymptomatic coronary or craniocervical atherosclerosis is a very low-fat diet (see Appendix F-2), because coronary atherosclerosis appears to progress with the typical American diet and standard low-fat diets. A very low-fat diet is aimed at reducing fat intake to 10% to 20% of the total calories and cholesterol intake to 5 to 10 mg per day or less.