What are polyunsaturated fats?
Chemically speaking, polyunsaturated fats are lipids in which the hydrocarbon chain contains two or more carbon-carbon double bonds. This essentially means that the double bonds are unsaturated and have the capacity to accommodate more hydrogen atoms, thereby gradually becoming saturated. When there are no more double bonds left in the hydrocarbon chain, the fat is said to be fully saturated. Importantly, oils that contain polyunsaturated fats are generally liquid at room temperature. However, at lower temperatures they start to solidify. Polyunsaturated fats are commonly referred to as polyunsaturated fatty acids (PUFA). In this article, we will use these terms interchangeably.
What are the sources of polyunsaturated fats?
There are many foods that are rich in PUFA. These are usually plant-based oils although other foods also contain them. The rich sources of PUFA are mentioned below:
- Soybean oil
- Corn oil
- Sunflower oil
- Olive oil
- Nuts and seeds
- Fatty fish such as salmon, herring, mackerel, trout, and albacore tuna
What are the daily requirements of polyunsaturated fats?
As per the Indian Council of Medical Research (ICMR) guidelines, the following polyunsaturated fats constitute the total PUFA pool:
- Linoleic acid (LA)
- Alpha-linolenic acid (ALA)
- Arachidonic acid (AA)
- Eicosapentaenoic acid (EPA)
- Docosapentaenoic acid (DPA)
- Docosahexaenoic (DHA)
The ICMR recommended dietary intake of PUFA for Indians, based on the percentage (%) of total energy (E) are given in Table 1.
Table 1: Recommended dietary intake of PUFAs
|Physiological groups/age/gender||Total PUFAs
(LA + ALA + AA + EPA + DPA + DHA)
|Adult man/woman||AI* 2.5-3.5|
|Infants||0-6 months||Human milk|
|6-24 months||U-AMDR** 15|
|Children (both boys and girls)||3-18 years||U-AMDR** 11|
* AI: adequate intake; ** U-AMDR: upper limit of accepted macronutrient dietary range
Package labelling: what does the FSSAI say?
The Food Safety and Standards Authority of India (FSSAI) is the apex food regulatory body in the country. The FSSAI, as per the Food Safety and Standards (Packaging and Labelling) Regulations, 2011, has clearly indicated that the nutritional information is to be indicated on the package display panel. Regarding fats, the composition of the following types of fats should be displayed:
- Total fat
- Saturated fat
- Monounsaturated fatty acids (MUFA)
- Polyunsaturated fatty acids (PUFA)
- Trans fatty acids
Why are the health benefits of polyunsaturated fats?
Polyunsaturated fats, along with monounsaturated fats are regarded as healthy fats. Consuming moderate amounts of these fats instead of saturated or trans fats can be beneficial to health. Polyunsaturated fats help to lower the levels of low-density lipoproteins (LDL) which is the “bad” cholesterol as it can cause blockage of small blood vessels that increase the risk of heart disease. Polyunsaturated fats bind to and clear out saturated fats, cholesterol and triglycerides which can cause coronary artery disease. Polyunsaturated fats have also been shown to benefit people suffering from mental illness. For example, studies have revealed that polyunsaturated fats improve depression. They have also been reported to be beneficial for children suffering from attention deficit hyperactivity disorder (ADHD).
Oils that are rich in PUFA also provide essential oils that are not produced by the body and therefore must be provided in the diet. Two of these essential oils are omega-6 and omega-3 fatty acids. Omega-3 fatty acids are beneficial to health and are found in fish oil, olive oil, canola oil, walnuts, peanuts, and almonds. Eicosapentaenoic acid (EPA) and docosapentaenoic acid (DHA) are the most beneficial of the omega-3 fatty acids. The American Heart Association recommends consumption of omega-3 fatty acids daily for optimal heart health.
Omega-3 fatty acids are beneficial in the following ways:
- These are cardioprotective
- These are anti-inflammatory
- Help in brain development in infants
- Help to maintain healthy hair, nails, and skin
Omega-6 fatty acids are present in large amount in safflower oil, which has the highest content (75%) of all dietary sources.
Omega-6 fatty acids are beneficial in the following ways:
- Help to control blood sugar
- Help to reduce the risk of type 2 diabetes mellitus
- Effective in lowering blood pressure in case of hypertension
In Conclusion: Why are polyunsaturated fats an ingredient of choice?
Polyunsaturated fats are important ingredients of many types of food, including processed foods. Most of these are generally good for a healthy lifestyle and are easy to digest. Some of these include the following:
- Breakfast cereals (corn flakes, chocos, muesli, oats)
- Baked products (breads, biscuits)
- Fruit juice (packaged)
- Coffee (brewed, espresso, decaffeinated)
- Salad dressing
- Italian dressing
- Ranch dressing
- Peppercorn dressing
- Sesame seed dressing
- Sunflower seed butter
- Sandwich spread
- Margarine spread
From the foregoing discussion, it is evident that polyunsaturated fats are a healthy alternative to saturated fats and trans fatty acids as the latter are harmful for the body. Polyunsaturated fats are not only nutritious but also quickly digested and easily assimilated by the body. As components of a balanced diet on a daily basis, polyunsaturated fats are important to keep various organs of the body in pristine condition and functioning properly. Therefore, the multiple health benefits of polyunsaturated fats as discussed above, underscore the fact that these are ideal ingredients of choice for a balanced diet and a healthy lifestyle.