Diet therapy in cardiovascular diseases
Cardiovascular diseases (CVD) remain the leading cause of death in the structure of total mortality. The percentage of premature death from cardiovascular diseases varies from 4% in high-income countries and 42% in low-income countries, leading to growing inequalities between countries and population groups. Since the extent of CVD continues to grow worldwide, there is an urgent need to increase awareness and to adopt a more intensive and targeted response at both international and national levels.
One of the most important components of CVD prevention is diet change — a change in the style of nutrition.
A very important task is the clear awareness of what a healthy lifestyle basically means: nutrition, physical activity and no smoking.
Nutritional care is often not as effective as medication effects, but avoids negative factors that can be observed in the application of drugs.
According to some experts, treatment with an appropriate diet and physical exercise can achieve not only the normalization of the lipid metabolism, but may also reduce the degree of atherosclerotic stenosis of the coronary arteries in patients with already established coronary artery disease.
The non-pharmacological correction of lipid disorders can be an effective method of both primary and secondary atherosclerosis prevention.
The development of a diet therapy for atherosclerosis should be made by a doctor, taking into account all features of the individual course of the disease. Severely restrictive diets may have a bad influence on the patient’s psycho-emotional status. However, all patients have to be advised to change the dietary patterns, as regards the intake of products rich in cholesterol and saturated fats, salt and alcohol.
Nutritional factors leading to atherosclerosis:
- Excessive caloric supply, especially when combined with a sedentary lifestyle;
- Excessive consumption of animal fats containing saturated fatty acids;
- Excessive consumption of easily digestible carbohydrates: fructose, sucrose, and possibly lactose;
- Excessive consumption of animal proteins;
- Excessive dietary intake of total cholesterol and low-density lipoprotein;
- Deficiency in the diet of vegetable oils containing essential fatty acids;
- Insufficient intake of dietary fiber;
- Insufficient dietary intake of lipotropic substances (methionine, choline, lecithin);
- Small consumption of vitamins, especially C, D, B6, B12, PP, E;
- Nutritional deficiency of Mg, K, I, Zn, Cr and other minerals;
- Excessive consumption of salt;
- Rare and abundant meals;
- Alcohol abuse.
Diet-keeping is recommended for long periods of time — up to 6 months, and only then, the physician should decide on prescribing dyslipidemia-correcting drugs. With proper dietary recommendations and their possible long-term compliance, the blood levels of lipids normalize in most cases.
If dietary restriction does not lead to a normalization of the lipid profile and the risk of coronary heart disease remains high, it is advisable to appoint lipid-lowering drugs. The limitation of their use is associated with side-effects and the need for long-term (almost lifelong) use.
The basic principles of diet therapy in dyslipidemia are:
- control of the caloric intake according to gender, age, and professional needs;
- maintenance of a normal body weight (body mass index less than 25 kg/m2);
- limited fat intake reaching 30% of the daily caloric intake (it is desirable that the proportions of saturated, polyunsaturated and monounsaturated fats are equal);
- limited supply of food-derived cholesterol, up to 300 mg/day;
- increased consumption of dietary fiber with decrease in the amount of carbohydrates;
- increased vegetable proteins and fish proteins, as compared to animal proteins;
- decrease in alcohol consumption.
Hypertensive heart disease is among the most common chronic diseases, the main manifestation of which is blood pressure elevation.
In most non-severe and uncomplicated cases, treatment should begin with a change in patients’ lifestyle and diet.
The principles and directions of diet therapy in hypertension are:
- reduction of body weight;
- limited alcohol consumption;
- exclusion of substances that excite the central nervous and cardiovascular systems (coffee, strong tea);
- increase of physical activity;
- limited salt consumption (no more than 6 g/day);
- adequate maintenance of potassium, calcium and magnesium intake;
- increased consumption of dietary fiber;
- exclusion of foods that cause flatulence (beans, milk, radish, onion, garlic).
Diet in hypertensive patients should be complete, balanced, containing a sufficient amount of proteins, fats, carbohydrates, vitamins and minerals. An important condition is moderation in eating. Since hypertension is often accompanied by atherosclerosis, the diet should limit animal fats, cholesterol, and digestible carbohydrates. Main dishes should be prepared mainly in boiled or baked form.
Food should be distributed evenly (at least 4-5 times per day), with the last meal not later than 2 hours before bedtime.
All food should be prepared without salt. When eating, it is allowed to add no more than 5-6 grams of salt per day.
The total amount of free fluid is equal to 1.5 liters.
Healthy food is one of the ways to treat coronary heart disease and to prevent its complications. Nutritional therapy is used as a standalone tool or as a background which increases the effectiveness of other means.
A diet’s success depends on observance of certain rules:
- People suffering from angina must lead a healthy lifestyle.
- Smoking should be prohibited.
- People leading a sedentary lifestyle, need to be engaged, systematically and cautiously, in physical exercise.
The diet principles in coronary heart disease are:
- As a basic rule, calorie consumption must correspond to the patient’s energy expenditure. Physical activity, usually reduced, decreases the caloric intake.
- The intake of salt should be substantially reduced.
- Substances that excite the central nervous and cardiovascular systems (alcohol, coffee, strong tea), foods rich in cholesterol, foods that cause flatulence (beans, milk, radish, onion, garlic) should be excluded from the diet.
- Alcohol is contraindicated.
It is recommended to increase the intake of foods containing potassium and magnesium (rice, wheat, plums, dried apricots, milk, oatmeal, cauliflower and cabbage, rose hips decoctum, carrots, beets, bran bread, potatoes, nuts, carp, perch, beef), foods rich in vitamins C and E (chokeberry, sweet red peppers, oranges, green onions, apples, fennel, parsley, black currant, strawberry, gooseberry, rose hips decoctum). In case of a significant increase of patients’ blood cholesterol level, drugs that lower the cholesterol level should be used, while some foods like egg yolks, butter, and cream must be excluded from the diet.
The nutrition of the patients with acute myocardial infarction is different, as the quantity and quality of products could have an adverse effect on the course of the disease: they can enhance or contribute to pain attacks, arrhythmias, heart failure or cause gastro-intestinal disorders.
During hospitalization of the patient with acute myocardial infarction it is necessary to provide adequate physiological needs in the diet.
It is necessary to adjust the amount of fluid intake in order to reduce workload on the heart.
During the first 2 days of myocardial infarction, patients receive drinks only 7 times a day. Frequent meals in small portions are recommended, and in the case of nausea — small pieces of ice. Consumption of large amounts of food at the same time should be avoided, as this may lead to discomfort in the stomach and thereby provoke new heart pain.
The food should be soft, should be served at room temperature, should not cause gas and nervous system excitement. Foods with strong odor, excessively hot or cold can irritate the vagus nerve and cause cardiac arrhythmias.
It should be considered that insufficient intake of proteins and vitamins in the organism can adversely affect the prognosis of the disease. The physician should assign a conventional, high-protein food, and additionally provide a mixture of aminoacids. Increasing the food’s proteic component is especially important in the first days of acute myocardial infarction in low-calorie diets, in which the part of the protein fraction should be generally increased.
After 5 to 10 days from the onset of myocardial infarction, the caloric intake increases from 1,200 to 1,600 kcal/day, and 2 weeks later, when the patient is allowed to leave — up to 2,000 kcal/day. The period of transition from one diet to another is determined by the doctor. Throughout the treatment period, patients should eat slowly and avoid strenuous exercise before and after their meals. The number of meals should be 6 times a day.
Chronic cardiovascular failure is the result of heart diseases and other illnesses. Its main feature is the presence of edema associated with fluid retention. The reason is not only the disorder of the heart’s contractile function, but also disorders of metabolic processes in other organs, tissues and cells.
The treatment of heart failure, especially diet therapy, should aim to eliminate or reduce the degree of metabolic disorders and restore the disturbed functions of the circulatory apparatus.
The most important general principles of the diet in chronic cardiovascular diseases are:
- limited consumption of salt up to 2-4 g per day, and in the presence of significant edema — its complete exclusion;
- limited fluid intake up to 0.8-1 liters per day;
- frequent meals in small portions (5-6 times a day);
- introduction of products that increase the excretion of fluids from the body, such as milk and foods containing potassium, which have a diuretic action.
Diet therapy in cardiovascular system diseases is an important and effective method of treatment, aimed at correcting the basic pathogenetic mechanisms that lead to metabolic disorders, discharging the cardiac activity to the maximum, potentiating the effects of drugs (diuretics, cardiac glycosides, etc.) and preventing their adverse effects on the body. This is why it is so important for patients with cardiovascular diseases to follow the basic rules of diet therapy, in order to live a longer and happier life.