|
dailynews |
|
|
|
|
|
OTHER LINKS |
|
|
|
|
|
|
|
Fats and oils are needed in the diet to supply energy or calories. Sugars (also known as carbohydrates) and proteins in our diet also supply energy, but on a gram to gram basis, fats and oils provide more energy than carbohydrates and proteins.
One gram of fat provides nine calories of energy whereas carbohydrates and proteins provide only four calories. Simply put, fat represents a convenient-energy rich food source, the consumption of which reduces the volume of food required.
However, most consumers are addicted to over-eating fatty foods because of their superior taste, which contributes towards excess of energy intake and if this pattern continues on a regular basis leads to overweight and obesity, which may pay the way for diabetes, hypertension and cardiovascular diseases.
This article provides some background information on dietary fats, their role in health and disease and some tips to consumers for selecting good, healthy fats for cooking, food preparation and deep frying.
Basic fats about fat and fatty acids
A number of foods contribute to the total amount of fat in the diet. For instance, fat is naturally present in many foods such as meat, fish, milk, nuts, seeds and pulp of certain fruits, in particular avocados and olives. A significant amount of fat in the diet however comes from oils and fats that are added to foods.
Coconut oil is the primary fat in the Sri Lankan diet and its main sources are coconut milk (pol-kiri), coconut salad (pol-sambol) and foods fried in coconut oil. Coconut milk is used by almost all the Sri Lankan householders for preparation of their daily foods, especially various types of curries and milk rice (kiri-bath).
For Sri Lankans a meal is not complete without rice and a curry prepared with pol-kiri. One dietary message for consumers has not changed in decades. Eat less fat.
This advice aims particularly at adults to reduce their risk of overweight, obesity, cardiovascular disease and diabetes. In recent years, a new message about fat has emerged that the type of fat in the diet is important.
Fatty acids
Fats are made up of smaller units called fatty acids. There are at least seven hundred different fatty acids occurring in nature, but only twenty or so are quantitatively important in the human diet, which are divided into three board classes; saturated, monounsaturated and polyunsaturated fatty acids. All natural food fats contain all the three classes of fatty acids but at different proportions.
Over 90 per cent of the fatty acid content of coconut oil is saturated fat and therefore coconut oil is classified as a saturated fat.
In fact, coconut oil has the highest amount of saturated fat of any dietary fat. Other oils or food that contain a high proportion of saturated fat are palm kernel oil, butter, whole milk cream, cheese and various other dairy products and eggs.
Although fat present in beef, pork, chicken and in other meats, would be considered by many people as being saturated fat, over 40 per cent of the fatty acid is monounsaturated and 10 per cent is polyunsaturated. Foods high in monounsaturated fatty acids include canola oil, olive oil, high oleic safflower oil, high oleic sunflower oil, peanuts, peanut oil and avocados.
The polyunsaturated fatty acid class includes two sub-families; the n-6 family (also known as omega-6) and n-3 family (also known as omega-3 family).
There are several n-6 and n-3 fatty acids in our diet. The parent fatty acid of the n-6 families called linoleic acid and that of the n-3 family is linolenic acid. These two polyunsaturated fatty acids are considered as essential fatty acids because our bodies cannot make them and we have to obtain them from foods.
Essential fatty acids are needed for the growth and development of brain and the central nervous system and keeping our skin healthy.
A lack of either of the two essential fatty acids will result in symptoms of deficiency that includes scaly skin, dermatitis and poor mental and cognitive development. In addition, the essential fats, in particular the n-3 fats protect against heart attacks and strokes.
People who eat diets rich in n-3 fatty acids have a lower risk of heart disease and cardiac deaths than people with low intakes of n-3 fats. Foods rich in n-6 polyunsaturated fatty acids include nuts, seeds and vegetable oils such as sunflower, safflower, corn and soybean oils.
Major food sources of n-3 fatty acids include plant seed oils such as flaxseed, canola and soybean oils and fatty fish such as mackerel, herring, sardines, smelts and salmon.
Fish oils extracted from fatty acid such as salmon are a very convenient source of n-3 fatty acids. Deficiencies of essential fatty acids are non-existent in Canada, the United States and in many industrialised nations.
The Sri Lankan diet is marginally deficient in essential fatty acids due to the widespread use of coconut oil as the primary source of dietary fat. Coconut oil contains very little linoleic acid (2 per cent of total fat) and no linolenic acid.
In addition to saturated, monounstaurated and ployunstaturated fatty acids, another class of fatty acids called trans fatty acids are present in human diets. Small amounts of trans fatty acids are naturally present in cow's milk and other dairy products and meat from ruminant animals.
However, most of the trans fat in our diet originates from processed foods, such as hard margarine, cakes, biscuits and crackers prepared using partially hydrogenated vegetable oils.
Partial hydrogenation converts liquid oils rich in polyunsaturated fatty acids into solid fats.
This process results in the conversion of the naturally occurring monounsaturated and polyunsaturated fatty acids to trans fatty acids.
From the Doctors' wives association:
A peace message to the world
At the Doctors' Wives Association sponsored Healthwatch special children's crossword draw to be held next Sunday (Dec. 17) at 6 p.m. at the Sri Lanka Medical Association (SLMA) auditorium at No. 6 Wijerama Mawatha (off Ward Place) Colombo 7.
The Association (DWA) in a peace message in poetry sung by a Council member Nalini de Silva carrying a baby in her arms, will acclaim to the world that this world belongs to the children the world over, the future generation who will continue the human race, the human family, and that we adults have always to keep that in mind all our activities personal, inter-personnel, national and international. So that their world is not destroyed by us by any of our actions.
Tasteful reading on AIDS
Dr. C. S. Egodage from the De Soysa Maternity Hospital, Colombo has sent us this note on a book on 'AIDS and Youth Sexuality' written in simple Sinhala by Dr. Duminda Handapangoda, which makes tasteful reading on a serious disease where prevention depends mostly on intense grasping of the subject by the public.
It is here that the art of writing comes into play, where details and facts have to be given in a palatable manner catching both eye and the mind and taste for information and knowledge.
This book amply fulfils that role, and a worthy book preventive on AIDS.
Vitamin E levels linked to mortality risk
NEW YORK: A large new study suggests vitamin E may help prevent death from cancer and heart disease in middle-aged men who smoke, contradicting the findings of some previous studies on the subject.
In a study of 29,092 Finnish men in their 50s and 60s who were smokers, those with the highest concentrations of the vitamin E in their blood at the study's outset were the least likely to die during the follow-up period, which lasted up to 19 years, Dr. Margaret E. Wright of the National Cancer Institute in Bethesda, Maryland and colleagues report.
There are a number of mechanisms by which vitamin E, also known as alpha-tocopherol, might promote health, Wright and her team note in the current issue of the American Journal of Clinical Nutrition.
For example, vitamin E is a powerful antioxidant, while it also boosts immune system function and prevents tumor blood vessel growth. But studies investigating blood levels of vitamin E and mortality, as well as the effects of taking supplements of the vitamin, have had conflicting results.
 |
|
|
|
|
|
|
|