Nutrition Meets Food Science

ESSENTIAL TO LIFE: Essential Fatty Acids

Fats have been always grabbing the limelight and taking all the attention most of the times amongst all the other nutrients. It has been shown down quite often for a person being obese or suffering from heart diseases and some others to count on. This maybe true to some extent but is it fair enough to blame fats for all the bad happening in our body?

Everyone is avoiding or cutting down fats from their diets. Fats carry 9 kcal per g which is more than double that is given by carbs and proteins. Also saturated as well as trans fats increase the chances of heart diseases.
But can we totally avoid fats? No, say the doctors. It is because there are some fatty acids that are essential for life and the body can’t make them.

Human body can synthesize most of the fats from another fats or fat substitutes but in case of essential fatty acids it solely needs to come from the diet as human body cannot make it. By this we understand that essential fatty acids are essential to life & must therefore be supplied through the diet in order to meet body’s nutritional requirements.

Chemically, essential fatty acids are Poly Unsaturated Fatty Acids (PUFA) i.e. containing several double bonds between carbon atoms. It is classified into two major fatty acids:

  • Omega-3(ω − 3) fatty acid
  • Omega-6 (ω − 6) fatty acid

What are omega 3 fatty acids?

Omega 3 fatty acids are essential fatty acids meaning your body cannot make them& therefore they need to come from diet.

There are three main derivatives of Omega 3 fatty acids –

  1. Alpha linolenic acid (ALA)
  2. Eicosapentaenoic acid (EPA)
  3. Docosahexaenoic acid (DHA).

How do these fatty acids benefit health?

  • Energy reservoir:
    As a fat their primary role is to provide energy to the body. Essential fatty acids are found in skin layer & also occur as triglycerides to provide energy to the body more rapidly than saturated fatty acids (SFA).
  • Essential fatty acid in early life:
    EFA plays a vital role in foetal growth & early human development. There is a suggestive evidence for a beneficial effect of omega 3 intake on child’s cognitive (mental) development. Also, there are significant association between dietary intakes of arachidonic acid (ARA) & docosahexaenoicacid (DHA) and birth weight, head circumference & placental weight. A child deficient in EFA has poor mental growth, maintenance &it may affect the child’s overall performance.
  • Improves cardiovascular performance:
    Eating a diet rich in α-linolenic acid has reverse effect on atherogenesis (accumulation of fats in arteries). Also, it prevents the blood vessels from any clot or blockages impeding blood flow. Hence, diet rich in omega-3 are recommended especially for patients who are at cardiovascular risks.
  • ω-3 fatty acids in cancer:
    It is found that omega 3 fatty acids helps in preventing breast & colon cancer in human by inhibiting growth of tumour cells. Also during chemotherapy, omega-3 fatty acid may have reduced inflammatory response and an increase active response rate to the treatment.
  • Brain & Central Nervous System requires particularly high proportion of Arachidonic acid & DHA. Also the photo-receptors present in the retina of eye needs high proportion of phospholipids containing DHA.
    All these functions are performed well when we eat diet rich in essential fatty acids especially omega -3.

ω-6 fatty acid:

Just like omega 3s, omega 6 fatty acids are polyunsaturated healthy fatty acid& we need to get omega 6 also from the dietary source.

There are four types of omega 6 fatty acids :

  1. Linoleic Acid (LA)
  2. Arachidonic Acid (ARA)
  3. Gamma Linoleic (GLA)
  4. Conjugated Linoleic Acid (CLA)

They also have functions similar to omega-3 fatty acid. Omega-6 play an important role in regulating our genes & promotes good immunity against bacterial infection.

Foods containing Omega 3 & Omega 6

Omega 3 fatty acids are found in:

  • Fatty fishes like salmon, mackerel, anchovies, sardines, cord, herrings, lake trout, tuna, etc.
  • Flaxseeds, rape seeds, chia seeds
  • Cod liver oil
  • Green leafy vegetables
  • Walnuts, soyabean, tofu
  • Eggs
    Image by the cozy apronImage by Keto Vale
  • Barley & oats also have appreciable amount of γ –linolenic acid which lowers the cholesterol levels.

Omega 6 are found in:

  • Corn, cotton seeds
  • Safflower &soyabean oils
  • Fish, egg, meat & poultry
  • Nuts & oil seeds

These foods are also called as “brain super foods”.

Role of fats in Indian diet

With an increasing association between obesity & non-communicable disease in India, essential fats being good fat plays a prominent role in our diet.

  • University of Eastern Finland states that Camelina sativa oil and fatty fish had a major effect on lipid metabolism. Several studies show that dietary fats can be used to target metabolic pathways that are linked with cardiovascular disease & type 2 diabetes.
  • Gamma-linoleic acid has anti-inflammatory properties that may help in reducing the symptoms of rheumatoid arthritis & other joint pain conditions in both adults & children.

Not all fats are bad, daily intake of small amount of healthy fats is necessary for normal growth and functioning of body. Fat intake of people differs from place to place depending on their culture, lifestyle, eating pattern & portion sizes.

Recommended intake on dietary fats for Indians:

Category Minimum level of Total  fats

(%E)

Visible fats to be consumed per day(g/p/d)
Infants 40-60 25 (for 6-24 months)
Children 25 25-30
Adult Men 20 25-40
Adult women 20 25-30
Pregnant Women 20 30
Lactating women 20 30

Source: RDA & EAR for Indians 2020

For a 6 months old infant, human milk should be the only source of dietary fats with minimum 40-60g of total fats whereas 25 to 30g of visible fats are recommended for children up to 9years of age.

Fat intake for both men & women varies depending on their range of physical activities.

An adequate intake of fatty acids is required during reproductive age to ensure enough nutrition to pregnant or lactating women as well as for growth & development of the foetus or infants.

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Abir Ansari

Jr. Nutritionist, PFNDAI

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