Omega 3 in Indian fish and in a vegetarian diet

 Omega 3 in Indian fish and in a vegetarian diet

Fish is the greatest source of omega 3 fatty acid. But which fish? You must have noticed it’s always Salmon, Sardine, Atlantic Macherel, Cod, Hering, etc, basically those fish that are not available or accessible for most of the Indians.  Therefore many of us have few doubts related to omega 3 fatty acid in the Indian diet.

The potential questions that you may have are –

  1. What exactly is omega 3 fatty acid? Why is it important?  How much of this do you need on daily basis?
  2. How about the omega 3 content of Indian fish like Rohu, Catla, Anchovy, Bombay duck, Hilsa, Bhetki, Indian Salmon, Prawn, etc? How much fish to eat for omega 3?
  3. Even if these fishes are good, how about mercury and formalin poisoning?
  4. What about vegetarians? How can they ensure omega 3 in their diet?

Let’s figure out the – what/how/why/when /how much – part of consuming regular Indian food rich in omega 3 fatty acid.

Omega 3 in Indian fish and in a vegetarian diet 1

What is omega 3?

Omega 3 fatty acid is an essential fatty acid that our body needs on a daily basis. Our body cannot produce it on its own but must be supplied through food.

ALA (alpha-linoleic acid), DHA (Docosa hexanoic acid), EPA (eicosa pentanoic acid) are the three main types of omega 3 fatty acids. ALA is mainly found from plant sources and DHA and EPA are present in animal foods.

A little amount of ALA can get converted into biologically active forms of EPA and DHA. EPA can also get converted to DHA. DHA is the most important omega 3 fatty acid in our body.

Why Omega 3 is important?

  1. DHA is vital for the health of the brain and retina
  2. Pregnant and lactation women must consume an optimum level of omega 3 on a daily basis
  3. It can fight against depression, anxiety
  4. It can reduce the symptoms of ADHD in children
  5. It is good for heart health
  6. It can fight against inflammation and autoimmune disorders
  7. It can reduce the symptoms of  metabolic syndrome like – belly fat, high blood pressure, insulin resistance, low HDL level
  8. It can improve mental disorders, Alzheimer’s disease
  9. It helps to prevent cancer
  10. It can reduce fat from the liver
  11. It may help to improve sleep
  12. It is good for the skin
  13. It can reduce menstrual pain
  14. It may improve bone and joint health (3)
Omega 3 in Indian fish and in a vegetarian diet2

How much Omega 3 you need on a daily basis?

As per Joint FAO/WHO, Expert Consultation on Fats and Fatty Acids in Human Nutrition, 2008, adult male and non-pregnant/non-lactating adult women should consume a minimum of 250 mg of EPA+DHA on daily basis. The dosage can increase up to 2 g based on the condition like cardiovascular disease.

As I have already mentioned above, the conversion of ALA into biologically active EPA or DHA is insufficient in our body. Therefore, if you are a vegetarian and not getting enough DHA and EPA from the diet, the most guideline recommends at least 1600 mg of ALA for men and 1100 mg of ALA for women. (1, 2. 5)

Table 1: Daily recommendation of Omega 3 fatty acid (ALA, DHA, EPA)

Age groupAdequate intake of  ALA/ dayAdequate intake of DHA+EPA/ day
0-6 month0.2- 0.3% of Energy (Provided from breast milk) 
6- 12 month0.4 – 0.6% of Energy 
2-4 yrs 100-150 mg
4-6 yrs 150 – 200 mg
6-10 yrs 200-250 mg
Adult0.5% of Energy250 mg – 2 g
Adult pregnant / lactation women 300 mg

What happens if one consumes an overdose of omega 3 for a prolonged period of time?

Every good stuff becomes poisonous when taken in excess continuously. As per experts consuming more than 3 g of omega 3 fatty acid per day might reduce the efficacy of the immune system. It increases lipid peroxidation and reduces cytokine production.

Omega 3 in Indian fish and in a vegetarian diet 3

Omega 3 fatty acid in common Indian fish

There is no doubt that fish is a great source of first-class protein, vitamins (including Vit B12), and minerals for a daily diet. Apart from this, fish fat is also quite healthy.

Indian fish is no exception. We are blessed to be in a country with natural diversity which brings us a wide variety of freshwater, marine water as well as brackish water fishes.

Coldwater, fatty fish are the best source of omega 3. However, even lean fish/low-fat fish or medium-fat fish also contain a good amount of omega 3 fatty acid.

The table below will give you an idea of omega 3 content of few popular Indian fish.

Table 2: List of few common Indian fish and it’s omega 3 & omega 6 content (4)

Common  NameScientific NameHabitatFat ContentOmega 3 (%) (EPA+DHA)Omega 6 (%)Omega 3/6 Ratio
Gangetic ailia / KajoriAilia coilaFresh WaterLean (<2%)9.327.70.3
Mola carplet/ MourolaAmblypharyngodon molaFresh WaterMedium (4-8%)1212.70.9
Climbing Perch/KoiAnabas testudineusFresh WaterMedium (4-8%)212.77.9
Catla         Catla catlaFresh WaterLow (2-4%)22.79.32.4
MrigalCirrhinus mrigala Fresh WaterLow (2-4%)7.835.70.2
Walking catfish/magurclarias batrachusFresh WaterLow (2-4%)2.822.71.8
Indian river shad/ ChapilaGudusia chapraFresh WaterMedium (4-8%)20.910.91.9
Bombay Duck- Loteyharpadon nehereusMarine WaterLow (2-4%)31.36.74.6
stinging catfish or fossil cat-  shingiheteropneustes fossilisFresh WaterLow (2-4%)7.36.91.1
Rohu/ RuiLabeo rohitaFresh WaterLow (2-4%)7.814.70.5
barramundi- bhetkilates calcariferBrackish WaterLow (2-4%)13.412.11.1
giant river prawn or giant freshwater prawn – golda chingri  Macrobrachium rosenbergiiFresh WaterMedium (4-8%)11.623.50.4
Flat head grey mullet – Chapta matha khorolMugil cephalusBrackish WaterLow (2-4%)13.24.72.8
Giant tiger prawn / Bagda ChingriPenaeus monodonBrackish WaterLean (<2%)22.016.31.3
copper mahseer / Boka/ BoolooahNeolissochilus hexagonolepisCold WaterLow (2-4%)20.910.32
Asian green mussel, – pool barb / Jat putiPerna viridisFresh WaterLean (<2%)22.64.25.3
rita – rithaRita ritaFresh WaterLean (<2%)9.51.95
Indian oil sardine  sardinella longicepsMarine WaterHigh  (>8%)21.44.94.3
Seenghala / giant rivar catfish/ aarSperata seenghalaFresh WaterLean (<2%)16.319.20.8
Tropical anchovyStolephorus commersonniiMarine WaterLean (<2%)9.04.02.2
Ilish/ HilsaTenualosa ilishaFresh Water, marine water, brackish water High  (>8%)14.25.42.3
yellowfin tunaThunnus albacoresMarine waterLean (<2%)12.715.60.8
king mahseer/ mohasholTor putitoraCold waterMedium (4-8%)   
largehead hairtail / churiTrichiurus lepturusMarine waterLow (2-4%)18.83.914.8
freshwater garfish – KakilaXenentodon cancilaFresh waterLean (<2%)1.11.40.7
Omega 3 in Indian fish and in a vegetarian diet 4

Hilsa (high-fat content), large head hairtail/ churi (low-fat content), Indian river shad (medium fat content) have a significant amount of DHA  934.5 mg, 567.8 mg, and 342 mg of DHA respectively.

Indian oil sardine (High-fat content), Hilsa (high-fat content), Cooper masher/ Boka (low-fat content) contain  937.9 mg, 304.5 mg, and 301.8 mg of EPA respectively.

Table 3: Few common Indian fish and it’s EPA & DHA content (4)

Common  NameScientific NameEPA (mg/100wet g)DHA (mg/100wet g)
Gangetic ailia / KajoriAilia coila 180.0
Mola carplet/ MourolaAmblypharyngodon mola94.6133.3
Indian river shad/ ChapilaGudusia chapra 342.0
barramundi- bhetkilates calcarifer155.2127.6
Giant tiger prawn / Bagda ChingriPenaeus monodon108.154.1
copper mahseer / Boka/ BoolooahNeolissochilus hexagonolepis301.8210.1
Asian green mussel, – pool barb / Jat putiPerna viridis169.9158.9
Indian oil sardinesardinella longiceps937.9534.9
Seenghala / giant rivar catfish/ aarSperata seenghala35.249.6
Ilish/ HilsaTenualosa ilisha304.5934.5
king mahseer/ mohasholTor putitora201.9115.5
largehead hairtail / churiTrichiurus lepturus203.1567.8
freshwater garfish – KakilaXenentodon cancila 70.0

How much fish to eat for omega 3?

Omega 3 content in Indian fish varies from species to species. If you are traditionally a fish eater and enjoy rice-fish like me, feel free to continue it.

If traditionally you consume fish regularly as part of your lunch or dinner, try to have one medium piece of fish along with dal, vegetables, curd, etc.  The medium size of the fish piece is generally about 75-100 g. It’s fine to have 300 – 400 g of fish in a week as a part of the meal. (8)

Don’t waste the fish skin, eat that too. Evidence suggests fish skin contains a good amount of omega 3 too.

Try to keep variety in your fish choices. Low fat, medium fat, high fat, lean fish, freshwater fish, marine fish, and brackish fish – choose fish from every category to bring the balance.

Omega 3 in Indian fish and in a vegetarian diet 5

Okay, but what about mercury in fish?

Yes, indeed it’s a matter of concern. Mercury is a common industrial waste. It releases into the air and then slowly settles on land and into the water. Microorganisms build on that and convert it into methylmercury.

Fish in the water starts absorbing it slowly. So the mercury found in fish is methylmercury. Fish that live longer and eat other fishes have higher levels of methylmercury.

Methylmercury poisoning is dangerous. It may lead to cerebral palsy, blindness, deafness, impaired mental function, impaired lung function, etc.

Therefore, it’s better to choose small and medium-size fish for regular consumption. Big fishes are better to consume in restriction.

The table below shows the category of fish as per the methylmercury load. Try to avoid giving high and very high mercury fish especially to women during pregnancy and lactation. (9)

Table 4: List of common fish as per mercury content

Low MercuryModerate Mercury
(consider eating
maximum 6
servings in a month)
High Mercury
(consider eating
maximum 3
servings in a month)
Very High Mercury
(Avoid eating)
AnchovyRohuSea BassShark
PomfretCatlaTuna (Canned Albacore, Yellowfin)Swordfish
TilapiaBassGrouperTuna
HilsaLobsterBluefish 
Catfish (Shingi)Tuna
(Canned Chunk light)
  
MackerelCod  
Mullet   
Indian Salmon   
Pink perch   
Shrimp   
Squid   
Crab   
Trout   

What about the usage of formalin in fish?

Yes, it’s again a serious concern. Formalin is toxic and can create a number of health hazards including cancer.

Formalin is used as a preservative to prevent its decay. It is used to wash the fish to control parasite infestation on the fish skin, gill, and fins.  

Therefore don’t forget to wash fish thoroughly.  Keep fish in saltwater for one and a half hours and then put it in a vinegar solution (with 20% vinegar) for another one hour. Next, wash it again with plain running water.

Central Institute of Fisheries Technology (CIFT), Cochin, and the Indian Council of Agricultural Research (ICAR) has developed an easy-to-use rapid formalin detection kit for fish. Food Safety and Standards Authority of India (FSSAI) recommends consumers to get the kit for rapid testing of fish before purchase. If you are interested, you can keep the kit handy before you go fish shopping next time. The kit will cost approximately Rs  50/-  containing 25 strips and reagent. Each test would cost  Rs 2/-.(10)

How to ensure omega 3 in a vegetarian diet?

Omega 3 in Indian fish and in a vegetarian diet 6

It’s absolutely fine if you are a vegetarian. You can still get omega 3 from your regular diet. As mentioned above, 1600 mg and 1100 mg of ALA (omega 3 from plant source) is needed for adult men and women respectively.  

Flaxseed, chia seed, walnut are the three rich sources of omega 3 for your diet. The table below will help you to choose the best omega 3 for your vegetarian diet.

Table 5: Common foods with high ALA content

FoodsALA content (per 100g)
Flaxseed7.8 g
Grounded flaxseed22.9 g
Flaxseed oil52.1 g
Walnut9.3 g
Walnut oil10 g
Chia seed18 g

Consider consuming any one of the item on daily basis to ensure your omega 3 (ALA) supply.

  • 1 table spoon (15 ml) of flaxseed oil (contain 7.8g of ALA)
  • 1 handful (20g) of walnut (Contain 1.86g of ALA)
  • 1 table spoon (15g) of chia seed (Contain 2.7g of ALA)
  • 1 table spoon (15 g) of grounded flaxseed  (Contain 3.4 g of ALA)

Don’t try to cook food with any of the above items specially with flaxseed oil. (11)

Use these in cooked food from the top. For eg, consider adding chia seed/ walnut or grounded flaxseed/ flaxseed oil with your – smoothie/ upma/ poha/ shake/ dressing/ dip  etc.

Omega 3 in Indian fish and in a vegetarian diet7

Isn’t there any other source of omega 3?

Yes, there are many other foods – dairy products, soy products, eggs, etc contain omega 3.  However, they are also high in omega 6 fatty acids. Omega 6 is another essential fatty acid which our body can’t synthesize but essential for multiple body function.

The ratio of omega 6 and omega 3 is very important in food. Confused? Let me explain.

LA or Linoleic acid (omega 6) and ALA (omega 3) compete for a particular enzyme to get digested in our body. That means if your diet is too high in omega 6 then omega 3 will have a very less chance to get digested.

Please note omega 6 is pro inflammatory whereas omega 3 is anti-inflammatory in nature.

ALA(omega 3 ) gets digested and then some of it gets converted into EPA and DHA, the biologically active form of omega 3.

Similarly, LA(Omega 6) also get digested and then converted into Arachidonic acid (AA), the biologically active form of omega 6.

Now both AA and EPA both metabolized to form a very powerful hormone-like substance – eicosanoid that affects out physiological functions like growth, cell division, inflammatory response, muscle activity, blood pressure, and immune function.

Eicosanoid formed from AA involved in response to injury, infection, stress, certain diseases. Whereas, eicosanoid formed from EPA helps to protect against heart attack, stroke, inflammatory diseases like lupus, asthma, arthritis.

Therefore if your diet is high in omega 6, your omega 3 requirement will also go up to maintain the balance. Otherwise, there will be no omega 3 left for digestion or metabolism.

Omega 6: omega 3 ratios ideally should be 1:1 to 4: 1. However in our current western influenced diet pushed this ratio to 15:1 to 17: 1. Needless to say, a lower number is better for our health. (12, 13)

Processed and refined vegetable oil is the biggest source of omega 6 in our daily diet. Therefore no matter how much omega 3 you are consuming, omega 6 always overpower omega 3.  It’s best to reduce omega 6 load in our body and start focusing on omega 3 instead.  (6)

Excessive omega 6 consumption leads to chronic diseases like coronary heart disease, an autoimmune disorder, metabolic diseases, cancer, etc.

4:1 to 2: 1 ratio of omega 6: omega 3 helps to suppress inflammation, asthma, better immunity, etc. (7)

Walnut, chia seed, and flaxseed have the best possible omega 6: omega 3 ratios. Therefore these three foods are must-haves in your kitchen.

Omega 3 in Indian fish and in a vegetarian diet 8

Table 6: Omega 3 & omega 6 content of few common foods

Food
(per 100 g)
Omega 3 content (g)Omega 6 content (g)Omega 6 : omega 3 Ratio
Walnut9.1738.14.2
Chia seed185.70.3
 Flaxseed6.351.40.2
Pumpkin Seed0.3519.0114
Sesame seed0.223.696
Soybean oil*6.550.77.8

*values are percentage of total methylester of fatty acid

Bottomline

Mindful eating is all you need to ensure your omega 3 supply. It is evident that a typical Indian diet – vegetarian or non-vegetarian –  both can fulfill all your nutritional requirements. Consider having fish.  Bring variety to your fish choice. If you are a vegetarian consider having walnut, flaxseed, and chia seed in your daily routine. Don’t miss to reduce your omega 6 consumption. Avoid refined vegetable oil as much as possible.

Enjoy food. Try to plan smart meal to avoid supplements.

Moreover, adopt a healthy lifestyle. Eat simple but good food, sleep well, stress less, stay active, and don’t forget to drink water. You will be fine.

Acknowledgement – Sagnik De, Zoology Graduate from University of Calcutta

Dr. Soma Chakrabarty

http://wellnessmunchcom.wordpress.com

Dr. Soma Chakrabarty has done her Ph.D. in Food and Nutrition in 2017. She is based in Hyderabad. She has 12 yrs of working experience in nutrition. Dr. Soma guides people to modify eating behavior and achieve the goal of wellness. She believes in a sustainable diet that helps people to live rather than survive.

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2 Comments

  • It was very resourceful and informative. Thank you. Keep us up-to-date with your resource.

    • Thank you very much for such lovely comment…. Keep reading our articles.

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