Fats are one of the three essential components of a balanced diet, the other two being proteins and carbohydrates. In addition, minor components such as vitamins and minerals are also essential, in the sense that they can enter the body only through the food we eat. The term fat includes oils also, generically called lipids.
The most important term in any discussion on healthy food is ‘balanced diet’. Nature in its evolutionary wisdom has ensured that the various forms of food naturally available to humankind have all the essential components mentioned above, packed in a matrix of dietary fibre, which is equally essential. All the components are not present in a single source. A sensible mix of the various natural food items will ensure this ‘balanced diet’, without the need for food supplements.
While it is understood that oils and fats are necessary components of food, this field is replete with misinformation and disinformation. What are bad dietary fats? The case against them is built upon two charges. One, they are ‘fattening’, and two, they contribute to coronary heart disease (CHD). The fattening effect, namely causing bulk and weight gain, is a charge that is true of all food, not fats alone. The food we consume is primarily used by the body for two functions, namely, as fuel, and as building and repair material. The second function is mainly the responsibility of proteins, though all the other ingredients of food also contribute to this function.
The first function, namely fuel, to provide energy for all activities physical and mental, is the role of carbohydrates and fats. A term that is widely used when talking about diet, is calorie which is a unit of energy. It measures, in this context, the amount of energy provided by the chemicals in the food when they are oxidised as part of the metabolic process. Our body is frugal in nature and has a built-in provision not to waste any excess nutrients that are left after meeting the energy requirement. The excess food is not excreted but stored in tissues for use on future occasions when there is food scarcity. This is the excess weight gain, and fats are not the only guilty ones on this front.
Also, a fact to remember is that all edible oils and fats, animal or vegetable, are nearly equal, weight for weight, in providing calories. So if calories are your demons and you want to reduce the risk of weight gain, the solution is to eat just the required amount of food, no more. If you still want to have a good meal or many good meals, one partial solution is to utilise (burn away) the excess calories by manual labour, exercise, yoga or what have you.
Coming to the other item in the charge sheet against fats, namely its role in CHD, it is linked in the popular understanding with the term cholesterol. Many vegetable oil manufacturers claim on their package label that their product is ‘100% fee of cholesterol’ — which is usually 100% true. What they fail to mention is that their competitor’s product is also free of cholesterol. Cholesterol is an animal product and is present in varying amounts in meats, egg and animal fats. But why are we so worried about cholesterol?
Early on it was discovered that there is a correlation between the cholesterol content of blood and CHD. It took years of research to absolve cholesterol, in part, from the charge that it is the main villain in CHD. Today we know that cholesterol is an important molecule manufactured in the liver and is the precursor for many other chemicals in the body. Any cholesterol that is present in the food we eat contributes only in a small way to the total cholesterol that is reported by the clinical laboratory in your ‘lipid profile’ report. So what is the connection between oils and fats in your diet, cholesterol in your blood and CHD?
One of the causative factors of CHD is the deposit of plaques on the walls of arteries, narrowing them and restricting the flow of blood. The composition of plaque is complex but it is safe to say they are composed of lipids, cholesterol and proteins. The degree of unsaturation and the type of unsaturation of the fatty acids of the lipids are among the factors that decide the ability of plaque to clog arteries. What a healthy diet needs is a combination of fatty acids with different degrees of unsaturation. Luckily, most or all natural edible oils contain a healthy mix of different degrees of unsaturation.
Do not believe the claim in advertisements that such and such oil is good for the heart. All oils are good if taken in moderation and definitely bad if taken in excess. Omega-3 fatty acids are touted as ‘essential’, but it is good to know that they are widely distributed in nature and need not be taken in the form of costly tablets. Trans-fats are bad, but no natural oil contains trans-fats. They are artefacts that appear only during processing, especially during hydrogenation. Some exotic oils like olive oil are good but not necessarily better than less-expensive indigenous oils. At one time there was much hype about polyunsaturated oils such as sunflower oil.
Today the hype seems to have dwindled. There was also much adverse publicity about coconut oil. This oil seems to have been exonerated of late of serious dietary sins. In fact, a good advice about diet is that if you hear that some food that you enjoy is bad for you, don’t panic and drop it completely. Reduce the intake of that item and wait; other research in the course of time may show it is actually good for you. And it is safe to rely on grandma’s wisdom, namely, all food including oils, which human beings have been eating from time immemorial, are good for health, if consumed sensibly and in moderation. The less processing and ‘refining’, the better, and the key word is moderation.