Written by: Prof. Anita Arsovska, MD, PhD,
Macedonian Organization for a fight against stroke, SAFE Board Member
Stroke is a severe impairment of brain functions due to acute brain circulation disorder. The highest percentage of strokes (80-85%) is due to thrombosis or embolism of the blood vessels, resulting in ischemia of the brain tissue. Approximately 10-15% of strokes are due to rupture of the blood vessel in the brain, with blood flowing into the brain, causing intracerebral, intraventricular or subarachnoid bleeding.
The symptoms of stroke are:
– weakness or paralysis of the arm and leg on one side
– paralysis of the face
– inability to speak and understand one’s speech
– headache, dizziness, blurred vision
– unstable or impossible walking
– nausea, vomiting (not related to food intake)
– consciousness impairment
There are so called risk factors that lead to stroke. Risk factors that may be modified are: elevated blood pressure, elevated levels of blood sugar and lipids, heart and blood vessel diseases, smoking, overweight (especially abdominal obesity), physical inactivity, excessive consumption of alcohol and narcotics, inadequate nutrition (excessive intake of salt, sugar and fat).
Aims of nutrition therapy
– primary and secondary prevention of stroke
– regulation of elevated blood pressure, elevated levels of blood sugar and lipids, overweight
– healthy diet (use of unsaturated fatty acids, cereals, fruits, vegetables, fish, olive oil)
The results of numerous epidemiological studies show that nutrition affects the pathogenesis of stroke and therefore, dietary changes can be preventive. For the prevention of stroke, the Mediterranean diet, consisting of olive oil, canola oil, omega-3 fish oil, balsamic vinegar, vitamins and antioxidants, is recommended while reducing the intake of trans fats, unhealthy fats of animal origin and cholesterol. This diet is characterized by the substitution of various harmful products with nutritionally healthy alternatives, such as canola margarine instead of butter, alpha-linolenic acid instead of animal fat, whole grains, fiber and phytoestrogens instead of other derivatives.
Previous studies on the impact of blood lipid levels and risk of stroke show different results. For example, in the Honolulu study, 7850 patients over 18 years were followed and have shown a positive correlation between elevated serum cholesterol levels and stroke. Another study analyzed 707 fatal strokes among 350,977 patients and found an increased incidence of ischemic strokes in patients with elevated serum cholesterol levels. A similar positive association was found in Oslo and Copenhagen, where 19,699 patients were followed up over a 10-year period, 693 of which have had a stroke. Most researchers believe that elevated blood cholesterol concentrations (> 8 mmol / L) are an important risk factor for stroke, especially ischemic stroke. It has been found that lowering LDL levels can prevent stroke in 35% – 80% of the cases, reducing the risk by 48% in patients with diabetes and 25% in patients with coronary artery disease.
Atkinson et al. found no increase or decrease in morbidity and mortality from stroke in middle-aged men when cholesterol concentrations decreased below 5.0 mmol / L. There are epidemiological studies that have shown a higher incidence of intracerebral (but not subarachnoidal) haemorrhage in patients with low serum total cholesterol. Low serum cholesterol levels below <4.62 mmol / L were associated with a significantly increased risk of intracerebral haemorrhage in men over 65 years of age. Increased risk was also seen in older women with low cholesterol levels, whereas no such association was seen in men and women aged 40-64 years.
Remember: There is a link between blood cholesterol levels and stroke. Cholesterol intake of up to 300 mg / day is recommended.
Cholesterol is found in egg yolk, brain, liver, kidneys, red meat (beef, veal, pork, lamb), game meat (roe, rabbit, etc.). The least cholesterol and saturated fat is found in fish, chicken and turkey breast. Saturated fat in high concentration is found in butter, sweet and sour cream, whole fat and melted cheeses, pork fat, pâté, meat cans, bacon, cheeses, sausages, salami, beef and mutton.
Frying should be avoided. If fats should be used, these should be solely of vegetable origin, such as olive oil, or soybean butter, sunflower seeds, or wheat germ, which contain linoleic acid. It should be noted that reheating the butter (eg in a deep-fryer) is not recommended, because this is increasing its hydrogenation which is very bad.
Sugar, protein, fish, meat
Studies show that high glycemic index foods increased the risk of stroke mortality (ischemic and hemorrhagic) in women in Japan, while higher sugar intake was associated with a higher risk of hemorrhagic stroke in middle-aged women and older women. Consumption of rice has been associated with an increased risk of stroke in China’s aging population and a reduced risk of cardiovascular disease in Japan.
The origin of the protein is very important in the nutrition. For example, it has been s shown that consuming fish has a protective effect against stroke. A repeated meta-analysis of 15 studies found that eating three fish during the week reduced the risk of stroke by 6%, while another study found that the risk of stroke was reduced by 17% by consuming fish on a daily basis.
Remember: Consumption of fish, especially blue fish (mackerel, anchovy, tuna, herring, salmon) is recommended for prevention of stroke, at least 2-3 times per week.
A meta-analysis of 20 studies to evaluate the effects of red meat consumption showed that the risk increased by 24% with daily consumption. The data indicate that the high intake of red meat (1 meal / day) is associated with an increased risk of stroke, while the high intake of poultry meat (1 meal / day) is associated with a 27% reduction in risk; the consumption of low fat dairy products is associated with a 11% reduction in the risk of stroke, the consumption of dairy products with whole fat, with a 10% reduction in the risk, and the consumption of nuts with a 17% reduction in the risk.
Fruits and vegetables
Greater use of fruits and vegetables in the diet is recommended, since it is associated with a reduced risk of stroke. For each supplement of fruits or vegetables per day, the risk of stroke is reduced by 6%. A meta-analysis of 9 studies, with a total of 257,551 participants (of whom 4,917 had a stroke), followed over a 13-year period, showed that consuming more than 5 servings of fruits and vegetables during the day could reduce the incidence of a stroke. Vegetables that are green in color and with leaves (such as herbs, broccoli, turnips), together with the nuts and citron juice, protect against stroke.
In the prevention of stroke, it is recommended to use products that contain whole grains of cereals, such as black and integral beans, cereals in various forms for breakfast, rice with husk etc. In the meta-analyzes, the introduction of whole grain products was shown to be associated with a downward trend in the incidence of stroke.
Remember: Consumption of fruits and vegetables, as well as whole grain cereals, is recommended for the prevention of stroke.
Electrolytes (sodium, potassium, magnesium, calcium)
Current studies have shown that high intake of sodium is associated with an increased risk of stroke, while higher intake of potassium through fruits and vegetables is associated with a reduced risk of stroke.
Remember: Increased salt intake is a risk factor for stroke.
Therefore, for stroke prevention, moderate consumption of salt is recommended, as well as not adding salt in the food.
The recommended intake of sodium is <2.3 g / day and the recommended intake of potassium is> 4.7 g / day.
A meta-analysis showed that the use of magnesium reduced the risk of stroke, especially of ischemic stroke. The effect of calcium use is uncertain, although meta-analysis data speak in favor against its use.
Multivitamins and antioxidants
A meta-analysis of 68 randomized studies with a total of 232,606 participants concluded that beta carotene, vitamin A and vitamin E supplements, alone or in combination, may increase stroke mortality, while the potential role of vitamin C and selenium require further research. Two further meta-analyzes for Vitamin E showed that this increased the risk of haemorrhagic stroke by 22% and decreased the risk of ischemic stroke by 10%. In randomized studies, vitamin C, vitamin B, and folic acid have not been shown to have a protective effect in relation to stroke. However, there is a positive correlation between homocysteine level and stroke. For this reason, the use of folic acid and B vitamins is recommended for patients who have elevated levels of homocysteine. Frequently, vitamin B12 levels are lower in aged population, so the use of this vitamin is justified. Numerous studies have shown that low levels of vitamin D are associated with hypertension, atherosclerosis, and cardiovascular disease. The results suggest that a high intake of vitamin D (≥600 IU / day) is associated with a lower incidence of coronary heart disease and stroke in men, but not in women.
Alcohol and caffeine
Excessive alcohol consumption increases the risk of hemorrhagic stroke, and the results of ischemic stroke are different. According to the recommendations for prevention of stroke, it is allowed to consume up to a maximum of 2 alcoholic beverages per day for men and 1 alcoholic beverage for non-pregnant women. Consumption of coffee (3-4 cups) and tea (> 3 cups) is associated with a reduction in stroke risk (17% and 21%, respectively).
– It is advised to maintain body weight close to ideal
– Moderate physical activity
– Stop smoking
– Proper medical treatment
– Regulating other risk factors
– Adopt a healthy lifestyle
Nutrition Recommendations for Stroke Prevention:
– To limit the use of saturated and trans fatty acids to a minimum, to avoid fried foods, fatty meat, butter and margarine and creamy or whole fat dairy products (instead of consuming lean meat, chicken meat, fish, vegetables and soya products);
– To minimize the use of highly processed, preserved and frozen products;
– Limit salt use to 2300 mg per day and substitute other spices and additives;
– To limit the use of alcohol to two beverages per day, and 1 beverage for women and especially low body weight (1 beverage = 340 ml beer, 140 ml wine or 40 ml 80% alcohol);
– To choose low-fat dairy products or low-fat products instead of high-fat dairy products;
– It is important to read the labels of the products and to choose the ones that contain “whole grain”, that is, use the whole, pasta and flour of “whole grain” instead of the products with white color;
– To consume a variety of fruit fruits (if the act of swallowing is normal)
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