Longevity Articles

How An Omega-3 Deficiency Can Make You Old and Sick

Prevent an omega-3 deficiency by consuming high amounts of fatty fish or taking fish oil supplements

While you've likely heard the term "omega-3s" before, you may not know exactly what that means. Your doctor may have mentioned them in passing, or you may have seen fish oil pills popping up on supermarket shelves. This is for good reason, as omega-3 fatty acids are crucial for our overall health and longevity. Unfortunately, our Western diet today has heavily altered the makeup of the fat ratios that we typically consume, meaning if you don't make a conscious effort to get omega-3s in your diet, you're likely not getting enough.

Keep reading to find out how we disrupted this ratio of omega fats and what you can do to prevent getting an omega-3 deficiency.

Omega-3 Fats: The Basics

Omega-3 fatty acids, also known as omega-3s, are a class of fats that are considered essential, meaning our bodies cannot produce them on our own and we must consume them through food or supplements. The three main omega-3 fatty acids are EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid), and ALA (alpha-linolenic acid).

Have you ever wondered why they are called omega-3 fats? Let's get technical for a minute: they get their name based on their chemical structure. They are polyunsaturated fats (PUFAs), which are made up of carbon chains with several double bonds.

The "omega" part comes from where the double bond is placed on that chain. The first double bond in an omega-3 fat will come up on the third carbon molecule in from the end of the fatty acid chain, while omega-6 fats have their first double bond six carbons in. Alright, chemistry lesson over! Visual learners, take a look:

Omega-3 and omega-6 fatty acid structures

(Image Credit: Generalic, Eni. "Omega-3 fatty acids." )

The most bioavailable forms of omega-3s are EPA and DHA, which the body can readily and easily use. The third form, ALA, can be converted in the body into EPA and then into DHA. However, this process is highly inefficient. On average, between 1-10% of ALA gets converted into EPA, and less than 1% into DHA [1]. Therefore, getting your omega-3s from EPA and DHA sources is your best bet.

Food Sources of Omega-3 Fats

The best sources of EPA- and DHA-rich foods are fatty fish, like salmon, sardines, mackerel, anchovies, and tuna. Eggs can be a source of omega-3s, if the hens are fed an omega-3 enriched diet (typically flaxseed), or if the hens are pasture-raised, which means they have ample access to eating grass and insects. One study found that eggs from pasture-raised hens had 2.5-times greater omega-3 fats compared to conventionally raised hens [2]. Similarly, grass-fed beef contains some omega-3s due to the cows grazing on grass.

Salmon and other fatty fish are the best sources of EPA and DHA to prevent omega-3 deficiency

Fatty fish get their omega-3 content from the algae they consume, making certain algae, like seaweed, spirulina, and chlorella, the only plant-based sources of EPA and DHA. However, you'd have to consume them in very high quantities to get a beneficial dose. Other plant-based sources of omega-3 fats contain ALA, rather than EPA or DHA. The foods with the highest ALA content are flaxseeds, chia seeds, hemp seeds and walnuts.

How We Upended the Omega-3 to Omega-6 Ratio

Although we do need omega-6 fatty acids in our diet, our current food supply and standard American diet has us consuming much omega-6s than omega-3s. Our ancestors likely had an omega-3 to omega-6 ratio of about 1:1. It's currently estimated that the typical Western diet has a ratio closer to 1:16, even up to 1:20 [3]. A healthy and realistic recommended ratio is about 1:4 for omega-3 to omega-6.

The main reason the ratio has been upended and we now over-consume omega-6 fats relative to omega-3s is the extensive use of industrial seed oils, which are cheap to make and are readily available. These oils include soybean, canola, vegetable, cottonseed, peanut and corn oils. Even if you don't cook with these oils in your kitchen, there's a high likelihood you consume them without knowing you are. For instance, soybean oil is the most commonly consumed oil, prevalent in many processed foods, and restaurant and fast food meals.

While omega-6 fats aren't inherently bad, they can be pro-inflammatory when consumed in the processed seed oil form. The main omega-6 fatty acid is linoleic acid (LA), which is also a polyunsaturated fat. The chemical structures of these fats (mainly, their amount of double bonds) make both omega-3 and omega-6 fats prone to oxidation. This increases pro-inflammatory signaling pathways in the body and can contribute to chronic disease [4]. There is also a cap on how much of each fat our bodies can contain, meaning omega-3s and omega-6s compete for space.

The nature of processing industrial oils exposes the seeds to excessive heat and light, both of which cause oxidation in the oil, leading to the creation of free radicals in our bodies when we consumed.

Oxidized fats can affect our health negatively by increasing pro-inflammatory pathways, which is at the core of all chronic diseases. This includes "inflammaging," the pro-inflammatory states that accelerate and contribute to the aging process [5,6].

Omega-3 fats are also prone to oxidation if exposed to excessive heat and light. For example, oxidation can occur if you leave fish oil pills in a warm and sunny place or use high-heat cooking with omega-3-rich oils like flaxseed oil. Omega-3 fats are delicate, so treat them that way!

A lesser-known group of fats is the omega-9s, which are non-essential in the diet, as our bodies can make them. Dietary omega-9 fats include oleic acid (found in olive oil and macadamia nuts), erucic acid (found in canola oil), and nervonic acid (found in salmon and nuts). For the most part, foods with omega-9s are healthful (just avoid the canola oil). However, too many dietary omega-9s can throw off your overall fatty acid balance, especially if you have an omega-3 deficiency.

Omega-3 Deficiency: What Are the Consequences?

The first signs of an omega-3 deficiency typically involve the hair, skin, and nails. The skin may become dry and inflamed and nails and hair can become brittle.

Most crucially, DHA is involved in the proper functioning of the brain [7]. Low levels of DHA have been linked to poor learning and cognition and an increased risk of neurodegenerative or mood conditions [8-10]. DHA is also essential in fetal and infant development, eye health, and vision [11-12].

In general, omega-3 fats reduce pro-inflammatory states, while omega-6 fats tend to promote them. During times of acute injury (like a cut or wound), the pro-inflammatory cytokines that omega-6 fats produce are necessary; however, it's the low-grade inflammatory states that persist that are dangerous to our health [13].

The disrupted ratio of omega-3 and omega-6 fats in our bodies today can cause structural changes in our cell membranes and DNA, leading to increases in chronic disease risk. Having beneficial amounts of omega-3s in the diet can support cardiovascular health.


The best way to prevent an omega-3 deficiency is to consume animal sources of omega-3s, namely fatty fish at least two to three times per week. You can get some, but likely not enough, if you eat pasture-raised eggs and grass-fed beef. You can include plant-based sources of omega-3s, like flaxseed, chia seeds, and walnuts. Even though the conversion rate is low, they are still healthy fat sources; however, don't count on them for your main omega-3 intake.

You'll also want to significantly reduce your omega-6 intake, which will make room for more omega-3s. Avoid industrially produced seed oils and instead, consume the whole-food sources of omega-6 fats, like raw nuts and seeds. Replace your canola oil with avocado oil for higher-heat cooking and use olive oil for dressings and low-heat dishes.

Omega-3 Supplements: Quality Matters

Supplements can be helpful to prevent an omega-3 deficiency if you're not confident that you can readily eat those foods weekly. However, the quality of the supplement does matter. As mentioned, omega-3 fats are susceptible to oxidation and rancidity if not properly made and stored.

Most omega-3 supplements are made of fatty fish oil, although krill oil is another option. Krill oil also contains EPA and DHA and may be more bioavailable than fish oil [14]. Cod liver oil is another option, which contains omega-3 fats as well as vitamins A and D. If you're a vegan or vegetarian, algal oil supplements can provide you with EPA and DHA with similar bioavailability to fish oil [15-16].

It's important that the omega-3 supplement gets tested for mercury, which builds up in larger fish, as well as other toxins or contaminants. While there is no set dosage for how much omega-3 content a supplement should have, beneficial amounts of combined EPA and DHA range from 250-500 mg, with a ratio of EPA: DHA of approximately 2:1. Taking up to 1,000 mg daily of DHA alone, or 5,000 mg combined EPA and DHA, can likely be taken without adverse effects [17]. However, omega-3 doses can vary widely from person to person and a therapeutic dose may be altered based on any conditions that they have.

Your Takeaway: How Can You Prevent Omega-3 Deficiency?

  • Omega-3 fatty acids are crucial in our diets; the most bioavailable forms are EPA and DHA, which are found mainly in the diet in fatty fish, with smaller amounts in pasture-raised eggs and grass-fed beef.
  • Omega-3s reduce pro-inflammatory states and support cardiovascular and cognitive health. 
  • A typical Western diet contains too many omega-6 fats, which promote inflammatory states. These fats are found in industrial seed oils, like canola, vegetable, soybean, and corn oil.
  • To prevent omega-3 deficiency, eat 2-3 servings of fatty fish per week or take a high-quality fish oil, krill oil, or cod liver oil supplement that has been tested for mercury and other contaminants.


  1. https://pubmed.ncbi.nlm.nih.gov/17622276-extremely-limited-synthesis-of-long-chain-polyunsaturates-in-adults-implications-for-their-dietary-essentiality-and-use-as-supplements/ 
  2. https://naldc.nal.usda.gov/download/41808/PDF
  3. https://www.sciencedirect.com/science/article/abs/pii/S0753332206002435
  4. https://openheart.bmj.com/content/openhrt/5/2/e000946.full.pdf 
  5. https://www.mdpi.com/2072-6643/8/3/128 
  6. https://academic.oup.com/milmed/article/179/suppl_11/76/4210217 
  7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6269634/
  8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808858/
  9. http://apjcn.nhri.org.tw/server/APJCN/28/4/675.pdf
  10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3738999/
  11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6087692/
  12. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2838628/
  13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5986409/
  14. x
  15. https://openheart.bmj.com/content/openhrt/5/2/e000946.full.pdf
  16. https://pubmed.ncbi.nlm.nih.gov/25884846-bioavailability-of-fatty-acids-from-krill-oil-krill-meal-and-fish-oil-in-healthy-subjects-a-randomized-single-dose-cross-over-trial/ 
  17. https://www.tandfonline.com/doi/full/10.1080/10408398.2011.596292
  18. https://linkinghub.elsevier.com/retrieve/pii/S0002-8223(08)00512-9 
  19. https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2012.2815

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