Have you ever felt your heart beat? Have you heard the sounds the heart makes when it beats? Have you at any time felt your heart ‘skip’ a beat? Have you ever wondered what would happen if the heart takes rest?
Well, many questions arise towards this extra ordinary organ in our body. As we all know that the heart works as it beats and these beats give us life. The heart beats nonstop. It starts beating from the time the heart is developed when the baby is in the mother’s womb, till we breathe our last. The heart is a hard working organ. It never takes rest. It works even while we sleep at night.
The heart makes a sound as it beats. The beats are caused by the opening and the closure of the four valves of the heart. The ‘lub’ sound is heard when the tricuspid valve and the mitral valve contract and relax. The ‘dup’ sound is heard when pulmonary valve and the aortic valve contract and relax. This ‘lub-dup’ sound is heard by doctors while they wear the stethoscope.
The heart, muscular in nature is the most important organ in our body. Located in the centre, between the lungs and protected by the rib cage, the heart cleans the entire body system. It brings in the deoxygenated (impure) blood, purifies it and supplies the oxygenated (pure) blood to the entire body.
The blood supply to the various parts in the body is carried out by the blood vessels. The arteries are broader vessels and they carry pure blood. The veins are narrower vessels and they carry impure blood. The blood vessels which carry blood to the heart are the coronary arteries. These coronary arteries supply blood to the various parts in the heart, and we can say that they connect the heart. Thus, any damage, blockage, thickening to these arteries can cause a problem to the heart.
Heart disease at times is also known as coronary heart disease and also coronary artery disease. Coronary heart disease (CHD) is a broad term comprising of the many conditions of the heart. It includes the disorders related to the circulation of blood, heart vessels and the heart muscles.
Coronary artery disease (CAD) refers to diseases of the arteries generally resulting in the blockage of the arteries.
Next, we shall look at common terminologies related with the heart disease.
– Dyslipidemia – Abnormal lipid levels in the blood
– Atherosclerosis – A thickening and narrowing of the walls of the large and medium sized blood vessels caused due to increase in the level of lipid and cholesterol in the blood
– Arteriosclerosis – Thickening of the walls of the smaller arteries
– Hypertension – Higher than normal blood pressure – Angina Pectoris – A characteristic pain or discomfort in the chest.
DIET & LIFESTYLE
The American Heart Association (2006) gives certain recommendations regarding the dietary changes and lifestyle to be followed by patients who are having cardio problems or those who are at a risk for it. Overweight and obese people can also follow the same guidelines.
– Balance food intake and output. A healthy weight is achieved by eating the right amount of calories and then exercising to maintain it.
– Consume a diet rich in vegetables and fruits.
– Choose whole grain, high fiber foods.
– Select fat free, 1% fat or low fat dairy products.
– Minimize intake of beverages and foods with added sugars.
– Eat smaller portions of food and have meals frequently. Six meals a day is a good way to maintain your weight.
– Track and whenever possible, reduce screen time (e.g. watching television, surfing the web, time spent on your mobile.)
– Choose processed foods that are low in salt. Read the Nutrition Facts Panel when buying a product.
– Use liquid vegetable oils at all times as compared with solid vegetable fat.
– Common forms of added sugars in packet foods are: glucose, fructose, maltose, dextrose, corn syrups, concentrated fruit juice and honey. Patients with diabetes must avoid all these forms of sugars. Read the Nutrition Facts Panel when buying a product.
FATS & OILS
Fat is the most fad word used in our lives today. Everyone is concerned about “how fat they are” or “how much fat they eat”? Fat, thus, has always been associated with weight. Although used negatively on most occasions, fat also exists as good fat which is required by our body to absorb vitamins, protect cells and lubricate bones. Let us now discuss on what are fats, the good fat and bad fat and how much it affects the heart in particular.
In the process of becoming conscious individuals, we have learnt to skip ‘fat’ from our diet. We have started to avoid the visible fats like fried snacks, chips, savouriesetc but are ignorant on our knowledge of invisible fat. Whole milk, red meat, ice creams, baked products, pastries appears to be equal in calories and as harmful as our fried snacks.
Any diet comprises of visible fat and invisible fat. Visible fats are the fats and oils used as such at the table or used for cooking. For example, vegetable oils, ghee, salad dressing, mayonnaise, butter, cream etc. Invisible fats are present naturally as an integral component of different foods. Flesh foods, whole milk, groundnuts, soybean, nuts and oilseeds have a high invisible fat content.
The foods that we consume contain cholesterol, saturated, monounsaturated, and polyunsaturated fatty acids. They may be invisible like fats present in various foods or visible like fats used in cooking. We shall look at each in detail.
Cholesterol is a natural component of foods of the animal kingdom. It does not exist in the vegetable kingdom. Cholesterol is found naturally in animal foods such as mutton, lamb, glandular meat (brain, liver and kidneys), chicken, eggs (yellow), whole milk, cheese, ice cream, butter and ghee. A normal cholesterol level in the human body has to be less than 200mg/dl of blood.
LDL cholesterol (Low Density Lipoprotein) is also known as the ‘bad’ cholesterol. LDL is known to be the cause of atherosclerosis and major heart disease. A value of 100 – 150mg/dl of LDL is required in the body. Values above 150mg/dl of blood lead to deposition of fat in the arteries.
HDL cholesterol (High Density Lipoprotein) is the good cholesterol. High levels of HDL in the blood are known to protect the heart. Exercise increases the HDL cholesterol. Up to 40mg/dl of HDL is needed by the human body.
Triglycerides – Triglycerides are fat in the blood. Their basic function is to provide energy to the body. When the fat in the body goes excess, these triglycerides are stored in the body especially in the hips and the waist region. These stored triglycerides cause problems. They can cause heart disease and people with type II diabetes are more prone to having high levels of triglycerides. A value of 150mg/dl of triglycerides in the blood is normal to the human body. Values above 150 are a warning sign. Diet and exercise will help reduce the triglycerides.
2. Saturated Fats
Saturated fatty acids also arise from animal fats as white marble-like solid at room temperature. A diet high in saturated fats will increase your LDL, thus leading to the hardening of the arteries. Foods high in saturated fats include red meat, milk fat, butter, ghee, coconut oil, palm oil, margarine and hydrogenated fats (vanaspathi).
3. Monounsaturated fats (MUFA)
MUFA are liquid at room temperature and are present in large quantities in oil. Olive oil, canola oil and groundnut oil are rich in MUFA. Monounsaturated fats are good fats because they reduce the LDL levels in the blood and increase the HDL levels. It thus helps in prevention of the hardening of the arteries, a term medically known as atherosclerosis.
4. Polyunsaturated fats (PUFA)
PUFA are also liquid at room temperature. PUFAs are known to reduce cholesterol levels in the blood. There are two main types of dietary PUFA’s.
– Linoleic acid (n-6) which is present in good amounts in safflower, sunflower, soyabean, corn and sesame oil.
– Alpha linolenic acid (n-3) which is found most in wheat, bajra, urad, cowpea, rajmah, soyabean, green leafy vegetables, mustard seeds, almonds and fish. Oils rich in Linolenic acid are mustard, soyabean, and canola and rice bran. The Indian Council of Medical Research (ICMR – 1998) has given dietary guidelines to maintain the n-6: n-3 ratio between 5 -10. This can be attained by using a mixture of two oils. Combination of safflower, corn, sunflower or sesame oil (rich in n – 6) with equal proportions of mustard oil or canola oil (rich n – 3) can give a ratio of 5 – 10.
OMEGA 3 FATTY ACID
Omega-3 fatty acids are polyunsaturated fatty acids and are important for normal metabolism. Omega 3 fatty acids are considered as essential fatty acids. This means that the human body cannot produce them and hence they have to be taken in the diet. There are three types of omega-3 fatty acids needed by us. ALA (alph-linoleic acid) which is found in plant oils, EPA and DHA which are both commonly found in animal sources.
ALA is found in oils such as canola oil, corn oil, soyabean oil, walnuts and flax seeds. EPA and DHA are found in fishes. The importance of omega – 3 fats is that it helps in reducing the LDL cholesterol and triglycerides in the blood. In the long run it reduces the risk of primary and secondary heart attack.
Hydrogenated fat is an important type of fat which has found its place in the Indian diets due to its characteristic flavor. It is available in the Indian market in the form of vanaspathi or margarine.
Hydrogenation is the process that turns liquid oil into a more solid fat. Liquid oils are ‘hardened’ by adding hydrogen to stabilise the fat, making it easier to use in recipes for biscuits, cakes, pastry, sweets and other processed foods. Hydrogenated fat is widely used in the market due to its flavor and long shelf life. Also, it is often preferred by many, as it is an imitation of pure ghee. However, hydrogenated fats provide no nutritional benefits. We should also remember that hydrogenated fat is saturated in nature and it contains Trans fatty acids. This increases the LDL cholesterol in the blood leading to atherosclerosis.
The heart pumps blood to the entire body through the blood vessels. As the blood travels in these vessels, it exerts some pressure on the walls of the vessels. This pressure is termed as the ‘blood pressure’. Thus, hypertension or high blood pressure is caused when there is an increase in the pressure applied across the blood vessels, particularly the arteries.
Compiled by Sakina Abdulqadir Vadnagarwala (Nutritionist, Kolkata)