Dietary fats are required by all us for many functions in the body. Fat is the most concentrated energy source in the diet — 1 gm of fat provides 9 calories compared to 4 calories from carbohydrates or protein. Fats provide insulation to the body, support vital organs and are needed to carry fat soluble vitamins like vitamin A, D, E and K.
Fats are formed from fatty acids which are of three main types — saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). Fat is a nutrient that is necessary for health. According to WHO, at least 10-20 per cent of our overall calories should come from fats.
SFA: Solid at room temperature. SFA can increase blood cholesterol levels, which increase the risk of heart disease.
PUFA: Liquid at room temperature. Corn oil, safflower oil, soybean oil, sunflower oil, cottonseed oil, walnuts, margarines are rich in PUFA.
MUFA: Liquid at room temperature. Olive oils, canola oil, peanut oil, almonds, pecans, hazelnuts, cashew nuts, are rich in MUFA.
MUFA and PUFA have a blood cholesterol lowering effect and can lower the risk of heart diseases. One essential difference between the two is that foods high in PUFA may lower HDL cholesterol —the “good” cholesterol — as well whereas MUFA rich oils do not lower HDL cholesterol which makes it a better choice between the two.
Trans Fats: Unsaturated fats can be made more saturated by adding hydrogen, a process called hydrogenation. This helps in increasing the shelf life of oils. Trans fatty acids are formed during the process of hydrogenation. Trans fatty acids, as well as hydrogenated fats raise blood cholesterol which is bad for heart. Salty snacks foods like chips, crackles made with partially hydrogenated vegetable oils contain trans fats.
Doctors recommend adopting an eating pattern that is lower in saturated fats and higher in MUFA/PUFA content. Total fat intake should not exceed 30 per cent and saturated fats should be limited to less than 10 per cent of total energy intake. Diets rich in SFA and trans fatty acids increase LDL cholestrol, one of the risk factor of heart diseases. Replacing SFA with PUFA/MUFA decreases the risk for heart conditions. Most of the fat in the diet should come from foods that are a source of PUFA/MUFA such as fish, nuts and vegetable oils.
Now, let us specifically talk about the oils available for our consumption. Most of the oils that have been used till now largely depend on where we stay or come from — mustard oil in eastern India, groundnut oil in western India, coconut oil in the south, sesame oil in north western India (Rajasthan). But now, awareness about other oils has changed our oil usage patterns. Oil behaves differently when heated: when it reaches its smoking point a lot of nutrients are destroyed and colour, taste or texture may change on heating the oil.
Let us look at the popular oils available in the market
* Groundnut oil: Good in MUFA/PUFA, low in SFA. All purpose oil
* Sunflower oil: Good in MUFA/PUFA
High smoking point, therefore widely used in frying chips, samosas and vegetables. Has the possibility of increasing sugar content; use with caution in diabetics
* Coconut oils: Full of SFA. Therefore bad for heart as it raises LDL cholesterol
* Mustard oil: Near ideal fat composition; rich in MUFA; high smoking point, very good for deep frying
* Canola oil: Lowest SFA among all oils, rich in MUFA; medium smoking point; good for fries/baking
* Olive oil: High MUFA content; decreased risk of heart diseases and cancer
* Extra virgin olive oil: Derived from first pressing of olives and is full of antioxidants; Good for heart
Finally, the oil you use is your choice but reading the label and having knowledge about SFA/PUFA/MUFA content will make your choice an informed one.
Also Read: Know Not What I Eat | Prakash Nedungadi | Sachidanand Madan The writer is senior consultant, Medicine, at Indraprastha Apollo Hospitals, Delhi. His special field of interest are lifestyle diseases and diabetes ,the knowledge about cooking oils being an integral part of all these medical conditions
.jpg)
