101 Fatty acids: A beginner’s guide to types, benefits, and sources
Fats and oils are part of macro nutrition in human diet. They provide higher calories per gram in comparison to other macronutrients, carbohydrates and proteins. Hence, they are placed at the top of food pyramid and are consumed in moderation than the other two macronutrients.
Constitutionally fats and oils consist of fatty acids as the glycerol esters. Fatty acids play multiple roles in good health maintenance. Generally, there are four kinds of fatty acids, namely saturated, monounsaturated, poly unsaturated, trans fatty acids. The fatty acids are organic in nature and are made of varying carbon chain lengths and having single or multiple double bonds in their framework.
Saturated fatty acids
In general, saturated fatty acids are found in fats such as lard and in oils from tropical trees such as coconut and palm. They are usually solid at room temperature. Animal fats usually contain saturated fatty acids in large proportion in comparison to oils from vegetables or nuts. Structurally these fatty acids don’t have any double bonds in their carbon chains and the carbons are fully saturated with hydrogens.
Saturated fatty acids play essential role in human health and should be consumed in moderation. Further, some saturated fatty acids, such as medium chain fatty acids, found in coconut oil found to have some health benefits although additional research is needed to support these claims.
Unsaturated fatty acids
Whereas unsaturated fatty acids are classified as either monounsaturated fatty acids (MUFA) or poly unsaturated fatty acids (PUFA) depending on the number of double bonds and their position in the carbon frame of the fatty acids. Mainly, they are classified as 3, 6, and 9 omega fatty acids depending on the position of double bond from the omega carbon atom (farthest carbon atom from the carboxylic group) in the chain.
Accordingly, when the first double bond in the fatty acid is on 3rd carbon from the omega carbon then it’s called an omega-3 fatty acid.
Similarly, omega-6, and omega-9 fatty acids wherein the first double bond in the unsaturated fatty acids are placed farthest from the omega carbon (methyl carbon on the other side of fatty acid).
Among the fatty acids, omega-3 and omega-6 fatty acids are called essential fatty acids because we need to get them from our diet as our bodies can’t make them. Whereas other omega fatty acids such as omega-9 fatty acids need not be obtained from our diet as our body can make them.
There are mainly three omega-3 fatty acids, namely alpha-lenolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Omega-3 fatty acids EPA and DHA are usually found in fatty fish such as salmon and marine algae, whereas ALA is found in plant oils (olive, soyabean, canola), flax and chia seeds, and walnuts and cashews.
While omega-6 fatty acids and monounsaturated fats are found in large quantities in vegetable oils such as sunflower, soyabean, corn oil and nuts and seed oils. There are couple of omega-6 fatty acids which are important, namely, linoleic acid and arachidonic acid which play important role in inflammation.
In the current research, it’s discovered that we are consuming higher proportion of omega-6 fatty acids (>10 parts) than that of omega-3 fatty acids (<1 part) in comparison to older generations when in fact 4:1 ratio of their consumption is preferred. This imbalance in their ratios of consumption creating several health problems which are rooted in higher inflammation.
Unsaturated fatty acids, especially omega-3 fatty acids, play important role in promoting optimal human health and in reducing the risk of chronic diseases.
Trans fatty acids
While trans fatty acids have a trans double bond in their carbon framework compared to omega fatty acids which have cis-double bonds in their carbon framework. Trans fatty acids are found in smaller quantities in vegetable oils.
However, their percentage is increased during over heating of vegetable oils, during deep frying or reheating the vegetable oils. They are also formed in higher quantity during hydrogenation of vegetable oils in order to get saturated fatty acids from unsaturated fatty acids.
Trans fatty acids are found to be harmful to human health and their consumption should be avoided.
Functions of fatty acids in our body
Fatty acids in general are very important constituents of human diet and they have multiple roles in human health. They act as energy sources in times of fasting or starvation and provide nearly double the energy during metabolism when compared to that of carbohydrates and proteins.
Fatty acids are main constituents of cell membrane, and they also maintain the passage of nutrients and wastage through them.
Various functional hormones are derived from fatty acids. For example, omega-3 fatty acids are the building blocks of prostaglandins which play important roles in various physiological functions.
For brain health, omega-3 fatty acids are essential in cognitive function, memory and mood. Their deficiency usually leads to mental disorders.
They also play important role in heart health, such as in lowering triglycerides and blood pressure, thus maintaining good heart health.
In various other bodily functions such as good immunity, eye development in infants and young children, soft skin, and weight management (medium chain fatty acids) fatty acids also play key roles.
Summary
Fatty acids are one of the macro nutrients for humans. Even though they are consumed in smaller proportions compared to the other macronutrients, the fatty acids play a bigger role in various bodily functions.
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