Wednesday,
September 2, 1998
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The
dread of mass breast cancer Stress:
flight, fright, fight? |
Fats & cholesterol: an
overview IT is common knowledge that fats, carbohydrates and proteins are the three major ingredients of all foods which together constitute the principal source of energy required for the physiological needs of the body. Of these, fats have lately been in the limelight because of the evidence that excessive intake of these can lead to some common diseases, especially heart disease and cancer. Since a lot of information, which can at times be confusing, has been appearing in the Press, it is the purpose of this write-up to provide a balanced overview on the subject. Much of the information provided is based on the researches carried out at the National Institute of Nutrition in Hyderabad. Fats are a family of chemical compounds made of glycerol and fatty acids. Most fats contain saturated, monounsaturated, and polyunsaturated fatty acids in different proportions and are classified according to the predominant constituent present. The accompanying table gives the classification of the common sources of fats in the human diet. The highlighted fats refer to the edible oils currently used as a cooking medium in different parts of the country. Refining of oils does not change their fatty acid composition though some other components are lost in the process. Edible fats are present in most food items, including vegetables. These are called “invisible” fat. For example, cereals contain 2% to 3% fat! Although some of the fat present in animal foods may be “visible”, a substantial amount of fat in such foods is actually invisible! Besides what is present in animal foods, visible fat is what is added in the cooking of food. The fats used for cooking may be in a solid or liquid form at room temperature. The higher the content of saturated fats the more likely it is that the fat will be in a solid form at room temperature. Fats provide, weight for weight, twice as much energy as do carbohydrates or proteins. They also promote absorption of fat-soluble vitamins (vitamins A, D, E, and K) that are essential for the body. Apart from providing energy, fats constitute a major component of some body fluids and cell membranes. Some of them, called essential fatty acids, provide vital nutrients for the body. It is, therefore, necessary that some amount of fat is taken in the diet. It is estimated that for a normal adult the total intake of fats from all sources (visible and invisible) should be such that it provides 15% to 30% of the total daily calorie (energy) intake. The diet of the rural population in our country contains, on an average, approximately 15 grams of invisible fat. The corresponding figure for the urban middle and high-income groups is 30 grams. Based on this assumption the total daily requirement of visible fat varies between 20 and 50 grams depending upon the physical activities of the individual. Persons who indulge in heavy manual labour may need the higher amount while those engaged in sedentary occupations would require the least amount. Children and adolescents may require about 25 grams of visible fats per day while pregnant and lactating mothers require 30 to 45 grams per day. One teaspoonful of fat weighs approximately five grams. Patients with heart disease are advised to limit their intake of fats to less than 20% of the total calories that they consume. Cholesterol is another substance which is normally present in the body and constitutes an essential element of all cells, especially the brain cells, and some of the hormones produced in the body. Although the body does manufacture some of the cholesterol that it needs, a substantial amount is ingested with the diet. Cholesterol, however, is found only in foods of animal origin such as milk and milk products, meat (especially organ meats such as liver, kidney and brain), egg yolk, shrimps and prawn etc. It is obvious that cholesterol is found in association with saturated fats. The daily requirement of cholesterol for an adult is less than 200 mg per day. It should be noted that one egg yolk contains 300 mg of cholesterol! Besides the cholesterol that one may ingest with food, the body makes its own cholesterol. The bile that is produced in the liver and secreted into the intestines is rich in cholesterol much of which is reabsorbed into the blood from the intestines. It is, therefore, that persons who exercise strict dietary control may find that their cholesterol levels remain high! Cholesterol contained in the blood is carried in an envelope that largely comprises a combination of fats and proteins called lipoproteins. It is these that are commonly measured in the blood and expressed as HDL, LDL, and VLDL. Although fats obtained from plant sources do not contain much of cholesterol, saturated fats promote the absorption of cholesterol from the intestines. Further, cholesterol containing foods when cooked in the presence of fats tend to get oxidised. This oxidised cholesterol is much more harmful for health than plain cholesterol! Besides, heating of fats produces toxic substances called free radicals. These tiny molecules damage a variety of cells in the body. It is for these reasons that there is so much emphasis on limiting the intake of fats and cholesterol. Of the different types of fats given in the table, the intake of saturated fats should be avoided as far as possible for reasons given above. Another very important consideration in making a choice of the most suitable edible fat for daily consumption is the relative proportions of n-3 and n-6 containing polyunsaturated fatty acids, also known as PUFA, present in these fats. It is known that both varieties of PUFA should be present in the human diet. Only two of the edible oils listed above contain significant amounts of n-3 PUFA. These are mustard oil and soyabean oil. For optimum nutrition, therefore, it is recommended that an equal mix of either of the two n-3 PUFA rich vegetable oils and any one of the other vegetable oils listed in the table provides perhaps the best combination. Fish oils are also a rich source of n-3 PUFA which is why fish are the preferred source of meat. Besides providing essential nutrients to the body, and being a rich source of energy, fats also add taste to the food. That is why individuals find it so difficult to limit the intake of fats, therefore, necessary that healthy food habits are inculcated right from childhood so that the craving for foods cooked in fats does not become a problem in later life. Further, it is much easier to prevent the increase in the level of cholesterol and fats in the blood than it is to control these subsequently by dietary control alone. Experience suggests that most patients who have increased levels of fats and cholesterol in the blood will have to take medication life long in order to keep these levels in check. Precautions taken early in life will promote better health in later life; after all prevention is better than cure. It will require a considerable effort to create the necessary awareness for a change in our national dietary habits so that the burden of crippling or fatal diseases in later life may be reduced. A beginning has to be made — and sooner than later. Dr
R.P. Sapru (RPS), the former chief of the Department of
Cardiology at the PGI, Chandigarh, is an internationally
known heart specialist, medical teacher and author of
repute. |
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The medical term "dropsy" refers to the collection of fluid under the skin or in various body cavities. In reality it is a general term since the collection of fluid could be due to any one of a number of causes. These include such diverse conditions as heart failure, kidney disease, liver disorders, fluid overload and so on. Dropsy is an archaic word which has been replaced by the general term "oedema". Epidemic dropsy refers to a situation in which a number of persons are affected by the same condition around the same time and is generally due to poisoning. Usually several members of a family are affected at the same time. The term has originated from the resemblance of this disease with the now more or less extinct condition of heart failure due to thiamine (vitamin B-1) deficiency popularly called Beri Beri. In India the condition has been known to exist at least since 1926 when Dr Sarkar from Calcutta showed that the disease is caused by the contamination of mustard oil with argemone oil. Experimental proof of the specific cause was provided in 1937 by Drs Lal and Roy. Cases have been reported from time to time from all the northern states from Kashmir to Bengal. The disease is caused by consuming the seeds of a plant called Argemone mexicana which is believed to have originated in the Americas and been subsequently introduced in the country much like the "congress grass"! The plant grows wild. It belongs to the family Papavaraceae and produces yellow flowers which resemble the flowers of the mustard plant. Even the spherical seeds resemble black mustard seeds. The toxic nature of the products of the plant hae been recognised by the Indian farmers for long as it is apparent from the colloquial names given to it: Sialkantha in Bengal, Darudi or Satyanashi in Gujarat, and Bharamdandi or Pila—dhatura in Maharashtra. Poisoning in human beings usually follows the intake of the seeds of this plant. Occasionally the seeds may get accidentally mixed with the seeds of the mustard plant and thus contaminate the mustard oil produced. One report mentions the occurrence of the disease by consuming bread made from wheat which had been contaminated by the seeds of this plant! However, more often the oil obtained from the seeds of this plant is deliberately used as an adulterant in mustard oil, linseed oil, sesame oil or arachis oil. The oil contains two alkaloids called sanguinarine and dihydrosanguinarine. The former is more toxic than the latter. As little as one per cent of argemone oil in mustard oil is sufficient to produce the clinical condition which is called epidemic dropsy. It is believed that the toxic substances in argemone oil block the metabolism of pyruvate which is produced in the body during most energy-producing metabolic pathways. The accumulation of unmetabolised pyruvate causes the disease. The disease is characterised by diarrhoea, sometimes associated with vomiting and loss of appetite which are soon followed by the appearance of oedema in the legs which rapidly spreads to the rest of the body. In severe cases the heart is affected and heart failure occurs which can be fatal. Difficulty in breathing is due to the heart failure. In the early stages oedema is due to a dilatation of the small blood vessels and capillaries as a result of which fluid oozes out of the blood vessels into the surrounding tissues. Occasionally, bluish patches or even nodules may appear under the skin due to the formation of small knots of blood vessels (angiomas). Similar lesions may be found in the mouth also. Tingling and abnormal sensation may be felt over the body and calf muscles may become tender. A few patients may even complain of dimness of vision due to increased pressure in the eyes (glaucoma). A recent documentation of 45 cases from Delhi reports that hair loss was present in 77.7 per cent cases, pigmentation in 33 per cent and enlargement of the liver in 24.4 per cent cases. use of the adulterated oil for hair care has been known to produce local burning and hair loss. Some years ago a couple of affected families were seen at the PGI in Chandigarh also. This time, however, no cases have been reported from these parts so far, but heightened vigilance is necessary. Unfortunately, no specific treatment for this poisoning is known. Treatment, therefore, is symptomatic. Of course, it is absolutely essential that further exposure to the contaminated oil is completely stopped. Although there are some possible approaches to the treatment of this disease but proof of benefit from such treatment is not available so far. It is unfortunate that greed continues to play havoc with innocent human lives. The need for prevention by strict monitoring of edible oils and exemplary punishment of the persons responsible for causing the adulteration are the only sure ways of preventing future catastrophes. A very vigilant public opinion is necessary to ensure that proper preventive measures are instituted. Detection of contamination is easily done by a simple test: addition of nitric acid to a sample of the oil will show a brown to orange-red colour if argemone oil is present. — R. P. S.
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The dread of mass breast
cancer ANNUALLY, it is reckoned, 60,000 new cases of breast cancer are detected in India, and nearly 20,000 women die of this disease (the actual figures are assuredly higher). After the cancer of the cervix, it is the second most common malignancy amongst Indian women. In several western countries it is the commonest. The morbidity and mortality of such magnitude demand diagnostic tools that the sensitive as well as cost-effective, and entail a general awareness of the malady. Unfortunately, many of those afflicted present themselves to the doctors at a fairly advanced stage — at a stage when a satisfactory cure is not possible. This is doubly unfortunate because breast malignancy — in contrast to the malignancy of internal organs e.g. the liver, the lung — can be detected in its early stages when not only is a complete cure for the patient possible; indeed the tumour can often be recognised in its pre-invasive stage. This introduces the concept of mass screening of the population which is at risk of developing breast cancer. In the developed countries there are well-organised breast cancer screening programmes. Teams of surgeons, mammographists, cytologists and histopathologists counsel and tend the female population at large, and the high-risk women in particular (i.e. women with a family history of breast cancer or with a history of cancer in the contralateral breast, among other known high-risk factors). In underdeveloped countries breast cancer screening programmes remain a distant goal. This can be attributed in equal measure to the cost of investigation and a general lack of awareness of the disease. As to this, perhaps more important than the specialists mentioned in the preceding passage, are the community health workers. These workers have a major role to play at the village level, where they can impart a general awareness of breast cancer, and at the same time teach breast self-examination. This would encourage women to come to the medical centres at the slightest suspicion of a lump or a nodule. Of course, the specialists too have all-important roles to play —the surgeon, of a meticulous clinical examination; the mammographist, of taking a special x-ray of the breast; the cytologist, of performing a diagnostic FNAC (needle aspiration) on suspicious lesions; and the histopathologist, of evaluating the surgically biopsied tissue. Even if costly mammography, cytology and histopathology are reserved for the high-risk women, it would go a long way towards reducing morbidity and mortality from this disease. It is high time we got down to business. If a national programme sounds too ambitious, maybe we should start at the state or the district level. The name of the game in breast cancer screening is teamwork. Regardless, there is an unfortunate trend among the players in the arena of wanting to play their solitary games. Mistrust of each other’s moves and a reluctance to share laurels are at the bottom of all “academic quibbles”. The practice of medical science is no exception. But petty rivalry is not conducive to the practice of good inter-speciality medicine. Game or no game, the question is not one of winning the adulation of riotous fans, but one of humble offerings at the temple of healing. The latter approach could help tackle some of India’s monumental health problems. Breast cancer is one of these. The author is a
well-known cytologist. He teaches and runs clinics at the
PGI, Chandigarh. |
Stress: flight, fright, fight? “The process of living is the process of reacting to stress” — Stanley Sarnoff. IT is common in the present times to hear frequently people talking about stress. Students, teachers, employers, employees, masters or servants, patients or physicians, all seem to be facing this problem called stress. Is stress always bad? Perhaps “stress” should be carefully differentiated from “distress”, which may be the real villain. What is stress? Is this a new phenomenon of this century or was it always there? The famous stress physiologist, Hans Selye, would have us believe that stress is observed in the entire animal kingdom. When an animal is faced with a stressful situation or a challenge, it reacts either by flight (runs away), fright (it frightens the enemy) or fight (it actually physically fights with the invader). The situation with human beings is more complex than the simple “flight, fright or fight” equation. By virtue of their education, status in society, social responsibilities — the very nature of the existence of this species — human beings cannot resolve their stressful situations simply by any of the above mentioned avenues used by animals. Even attempting to define stress seems to be stressful for me! A physicist will define stress as force, equal to mass into acceleration divided by area; but how does a physician define stress? The closest to an accurate definition of stress that one can think of is: “An altered state of the mind as a result of the discrepancy between the environmental demands and the individual’s capability to meet these demands.” “The demands may be personal, social, cultural or community based. If this phenomenon is repetitive, it may result in certain abnormalities in the human system, and especially affect the endocrine organs and the cardiovascular system. Causes of stress: The factors that set in place the reaction that results in a stressful situation of the mind varies from person to person, but the following factors may initiate or aggravate stress or tension either in the person who inculcate these factors or in those who are around that person: (i) Negative emotions such as anger (krodha), greed (lobha), attachment (moha), desires (kama) and egoism (ahankara). These may give temporary satisfaction to the person but, invariably, sometime or the other, will disturb the mind, setting it in disequilibrium and stress; (ii) corruption in thought or deed invariably puts the person and those around him or her in a restless state of the mind, culminating in a stressful situation for self and others. A corrupt person may himself or herself not be under stress, but it is his or her corrupt means and undue demands that put others — especially the clean ones — under stress. Effects of stress on the cardiovascular system: The major effects that stress has on the heart and blood vessels include: (i) Effect on the heart beat, both the frequency of the heart beat and the force of its contractions increase; (ii) rise in the blood pressure, especially the systolic kind. The net result of the rise in the pressure on the heart and the blood pressure is the increase in the oxygen demand by the heart muscle, which may not be met effectively if the coronary arteries that carry the oxygenated blood to the heart muscle are narrowed due to atherosclerosis (coronary artery disease); and this may result in anginal chest pain or a heart attack (myocardial infarction); (iii) coronary spasm (constriction of coronary arteries), which could result in sudden cardiac death, is one of the most harmful effects of stress. The commonest cause of sudden death, apart from accidents, is coronary heart disease. Realising the role of stress on the heart, Ayurvedic texts say: “Those who wish to protect the heart and its roots (coronary arteries) should scrupulously avoid all that causes afflictions of the mind (stress)”; (iv) development and aggravation of hypertension; (v) increased blood levels of catecholemines (adrenaline and noradrenaline), the hormones that push up the heart rate and the blood pressure. This effect will be extremely harmful if the patient under stress already has high blood pressure. A stressful situation may push up the already high blood pressure to dangerously high pressure levels that may result in a catastrophe such as a stroke, acute myocardial infarction, left heart failure (pulmonary oedema), or dissection of the aorta; (vi) increased blood viscosity, making the blood more thick; (vii) enhanced stickiness of blood platelets so as to initiate clot formation inside the small blood vessels — the blood vessals of the brain and of the heart (coronary arteries) being specially prone; (viii) increased cardiac output and peripheral resistance; (ix) rise in blood lipids like cholesterol and triglycerides; and (x) onset of cardiac arrhythmias, i.e irregularity of the heart beat and palpitations. Stress is one of the major causes of missing beats (ectopics or extra beats) and some other cardiac arrhythmias and rarely the occurrence of the more serious ventricular tachycardia and ventricular fibrillation which, if not immediately attended to, may prove fatal. (To be concluded) For further
information, read the doctor’s book,
“Traditional Wisdom for Heart-Care” (Vikas). Dr
Wasir is the Chief Cardiologist and Medical Director of
the Batra Hospital and Medical Research Centre, New
Delhi. |
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