It was called the “Eskimo Paradox.” How was it that Eskimos in northwestern Greenland, with their mega intake of dietary fat and cholesterol, which made up a whopping 40% of their calories, had less heart disease than Danish settlers?
Was their diet of fish the key to not keeling over with a heart attack? Scientists concluded that yes, it was, and this was believed for decades. But further investigation threw a spanner in the works.
That's because it was discovered that Eskimos don’t have less heart disease. In fact, they had a higher death rate from heart attacks than the Danes living there! Their primary food source wasn't even fish; it was mammal protein. Oops!
Yet even flawed and shoddy research from half a century ago has its place because it led to copious research into the omega-3 fatty acids EPA and DHA found in fish. This means we now have a much better understanding of how important these fatty acids are to our health and what can happen when we don't have enough of them.
Key Takeaways
There are three omega-3 fatty acids: Alpha Lipoic Acid (ALA), eicosapentaenoic acid (EPA), and docosapentaenoic acid (DHA). Omega-3s are important for the health of the heart, eyes, and joints, especially the brain. They can even slow the aging process and protect against age-related diseases.
Eating foods that contain the omega-3 essential fatty acid ALA is easy. When we do, we also benefit from the two other omega-3s, EPA and DHA, which the body makes from ALA.
Low omega-3 symptoms can show up in problems with your skin, hair, nails, joints, and eyes, and in the brain, with lower concentration and depression.
Understanding the Three Types of Omega-3 Fatty Acids
All fats have their own specific chemical structure, giving them a range of different functions and uses in the body and the way they appear in foods.
Saturated fats, in spite of their bad reputation, have important and specific roles in cells, and in foods that contain a lot of them they’re typically solid at room temperature like beef or butter. Most people consume more than enough of these kinds of fats - no shortfall there, unlike omega-3.
The omega-3s are polyunsaturated fats and are typically liquid at room temperature. The omega-3 fatty acid, alpha-linolenic acid (ALA) must come from the food we eat because the body can’t make it. Since we need some each day to stay in good shape, it’s classified as an essential fatty acid (EFA). Inside the body it goes through several reactions until it’s converted to eicosapentaenoic acid (EPA) and after more reactions, to docosapentaenoic acid (DHA).
EPA and DHA are not essential fatty acids because they can be made from ALA. But a low intake of ALA will produce a shortfall in EPA and DHA. Even if we get a heap of ALA from our diet, the body only converts a very small amount of ALA into the other omega-3s.[1]
To add to this low conversion, the first reaction, which converts ALA to stearidonic acid, requires an enzyme called delta 6 desaturase. This enzyme can become faulty or dysfunctional, a problem that “is increasing rapidly in the population.”[2]
Linoleic acid (omega-6) competes with EPA and DHA for this enzyme. Since Western diets typically contain an abundance of omega-6 fats compared to omega-3, linoleic acid wins, reducing our ability to make these omega-3s even further.
It gets even worse.
To convert ALA to the other forms, you need zinc, magnesium, and other nutrients, which are often deficient, especially in non-meat eaters. For all these reasons health authorities recommend we eat foods rich in EPA and DHA to ensure we get our fill, although it's important to note some scientists say the low conversion from ALA to EPA/DHA is how the body was designed and only tiny amounts are needed to fulfil its functions.
Alpha-linolenic acid (ALA)
ALA is found in the oil of plants such as flaxseed, chia seed, and hemp seed, and in grass-fed or pasture-raised beef and lamb.
It has important roles in:
growth and development
reproduction
maintaining cell structure
keeping blood cholesterol at normal levels
regulating gene expression
vision
maintaining healthy skin
Eicosapentaenoic acid (EPA)
EPA helps reduce inflammation, maintain normal blood pressure, and has key roles in neurological and cardiovascular health. It’s effective for reducing higher-than-normal levels of blood fats (triglycerides) and prevents the blood from clotting too easily. EPA also produces eicosanoids, compounds that influence a network of controls in the body, particularly related to inflammation and immunity.[4]
Docosahexaenoic acid (DHA)
DHA is found in high concentrations in the brain, where it’s involved in signaling between brain cells. It’s vital for brain development and function in childhood, as well as brain function in adults. High amounts are also found in the retina, and it’s therefore needed to maintain good vision. It’s also involved in cell membrane structure and function, and in cellular signaling.[5]
Sources of Omega-3 Fatty Acids
Omega-3 fatty acids can be found in both plants and animals.
Plant Sources (ALA)
The primary source of ALA is found in plants. It’s concentrated in seeds and nuts. The top healthy plant sources are:
Flax seeds and flaxseed oil
Chia seeds
Walnuts
Pistachio nuts
Pine nuts
Edamame (Green Soybeans)
Navy beans
Cherimoya (Custard Apple)
Avocado
Zucchini
Animal Sources (EPA and DHA)
EPA and DHA are found in the liver of lean white fish, in the body of oily fish and in shellfish.
Top sources are:
Herring
Salmon
Mackerel
Tuna
Sardines
Trout
Cod
Haddock
Anchovies
Bass
Oysters
Shrimp
Mussels
Crab
Vegetarians, vegans and those who don't like fish can get EPA and DHA from marine algae.
Eating More Omega-3s: Omega-3-Rich Diets
As previously mentioned, Western diets, which include the standard American diet (SAD), contain over-the-top amounts of chemically altered and only partially functional omega-6 in relation to omega-3. This is estimated to be around 15 or 20 to 1 in favor of omega-6, whereas a ratio of 1:1 to 2:1 is consistent with evolutionary aspects of diet, neurodevelopment, and genetics.[6]
The major culprit for this overabundance of adulterated omega-6 is processed cooking oils and the thousands of products lining the supermarket shelves that contain them. The solution is not simply to consume more omega-3 foods to improve the ratio. That won't get you very far.
The solution is firstly to avoid using these nasty oils and replace them with extra virgin olive oil, coconut oil, avocado oil, or clarified butter (ghee), and secondly to avoid or cut back as much as you're willing on processed foods, microwave meals, fast foods, etc. This is the only way to seriously lower adulterated, mostly non-functional omega-6 and improve the ratio. (As an aside, people on the SAD diet actually have a deficiency of functional omega-6)
Kick SAD out and solve the omega-6/3 ratio problem with a diet that is more in line with a Mediterranean-style diet, which is rich in unsaturated fats, vitamins and minerals, antioxidants, polyphenols, and spices. The diet emphasizes vegetables, legumes, fruits, unrefined cereals, nuts, olive oil, low to moderate dairy foods, moderate to high amounts of fish, limited consumption of red meat, and modest amounts of alcohol. This balanced diet will provide fully functional omega-6 and omega-3 in healthy ratios.
Health Benefits of Omega-3 Fatty Acids
Healthier Heart
An analysis of 17 trials involving over 45,000 people found higher levels of omega-3 were linked to a lower risk of fatal coronary heart disease (CHD). Another review of 345,000 people free of cardiovascular disease found higher levels of dietary ALA were linked to a 9% lower risk of developing heart conditions and a 15% lower risk of dying from heart disease.
Yet when it comes to trials that come in the randomized, controlled category, far fewer benefits are seen. One major review found omega-3 fish oil supplements had no effect on the risk of heart disease or death from heart disease. Another from the American Heart Association also found little evidence to support their use in those with healthy hearts but suggested it might help those with existing CHD.[7]
Even though omega-3 lowers triglycerides and may help lower blood pressure and improve blood flow, a possible reason for these disappointing findings is that the intima, which is the inner lining of the arteries, “is 100% exclusively made of LA” (linoleic acid, omega-6). There are no omega-3 fatty acids in the intima.[8]
The current position of the National Institutes of Health is that seafood promotes heart health, yet evidence for fish oil supplements is weak, possibly helping those who already have CHD.[9]
Overall, the highest quality research shows ALA is important for heart health and can protect against a heart attack rather than EPA/DHA. So if your heart is your top concern focus on ALA rich foods, but if you're more interested in keeping your brain in apple-pie order...
Sharper Memory and Balanced Mood
The brain is 60% fat; it’s the fattest organ in the body and, as we’ve already mentioned, more DHA is found there than anywhere else apart from the eyes, which are extensions of the brain. DHA also makes up 30% of cell membranes in the brain’s grey matter - the darker, outer portion of the brain. EPA is also essential to the brain and plays a role in many cellular processes.
For these reasons it should come as no surprise that human studies confirm the importance of omega-3 fats in cognitive health.
A paper published by the American Academy of Neurology (AAN) showed women with higher levels of omega-3 fatty acids had bigger brains compared to those with much lower levels. This includes the hippocampus, which plays an important role in memory. Shrinking brain volume is a sign of Alzheimer’s disease as well as normal aging. Lead author James Pottala said, “the effect on brain volume is the equivalent of delaying the normal loss of brain cells that comes with aging by one to two years.”[10]
Another AAN study produced similar results. It found diets lacking in omega-3 cause the brain to age faster and lose some of its memory and thinking abilities. Study author Zaldy S. Tan said: "People with lower blood levels of omega-3 fatty acids had lower brain volumes that were equivalent to about two years of structural brain aging."[11]
A study out of the University of Texas (UT) found, like the AAN studies, that a higher omega-3 index - a measure of blood concentrations of EPA and DHA - was linked with larger hippocampal volumes in addition to better abstract reasoning and enhanced cognition in middle age.
One of the study authors, Debora Melo van Lent said: “Omega-3 fatty acids such as EPA and DHA are key micronutrients that enhance and protect the brain." Her colleague and lead author Claudia Satizabal added that “even at younger ages, if you have a diet that includes some omega-3 fatty acids, you are already protecting your brain for most of the indicators of brain aging that we see at middle age."[12]
Another UT study showed people with higher omega-3 levels had increased blood flow to key brain regions needed for healthy cognition. Lead author Daniel G. Amen said, "This is very important research because it shows a correlation between lower omega-3 fatty acid levels and reduced brain blood flow to regions important for learning, memory, depression and dementia." His colleague William Harris added: “This study opens the door to the possibility that relatively simple dietary changes could favorably impact cognitive function."
The University of Pittsburgh has also been studying omega-3. In one study they discovered that even healthy young adults can improve their working memory by increasing their omega-3 intake. Neuroscientist Bita Moghaddam, who led the study, was astonished by their results saying, "Before seeing this data, I would have said it was impossible to move young healthy individuals above their cognitive best," and yet that’s precisely what he witnessed.[13]
In another study they investigated the improvement in mood often seen with higher levels of omega 3. They found those with elevated levels were more agreeable and less likely to report mild or moderate symptoms of depression. They think this could be because raised levels show increased grey matter volume in areas linked to mood and behavior.[14]
Better Eye Health
Omega-3 is needed by the retina, and may help prevent macular degeneration and dry eyes.
Abundant levels of omega-3 found in the retina led researchers at the National Eye Institute, National Institutes of Health, to look at its role there. They concluded that omega-3 plays a protective role in various factors that impact the health of the retina, so low omega-3 could create vision problems.[15]
Age-related macular degeneration (AMD) is the major cause of adult blindness in developed countries. In two studies published in the American Journal of Clinical Nutrition, the first found eating oily fish at least once a week compared with less than once per week halved the risk of succumbing to the condition, while the second found those with the highest intake of omega-3 were 30% less likely to develop it. [16] And a research review found that “many studies reported a positive effect of the intake of fatty acids, mainly DHA and EPA, in the prevention and treatment of AMD.”[17]
It’s also good for dry eyes. According to the Mayo Clinic, an omega-3 fatty acid supplement can reduce symptoms.[18]
Pain Relief and Reduced Inflammation
Omega-3 has anti-inflammatory properties and produces molecules called resolvins, maresins, lipoxins, and protectins, which are collectively known as specialized pro-resolving mediators (SPMs). These play important roles in resolving inflammation.
This has led to research to find out if omega-3 has value in joint pain. In lab research, omega-3 supplements lower inflammation, slow the breakdown of cartilage, and limit the progression of pain symptoms. Some human trials have shown little or no benefit, while others showed an improvement in pain and function with fish oil and improved pain, stiffness, and physical function with krill oil.[19]
Anti-Aging
Cells won't function normally without sufficient omega-3, so they're important to most body systems. In a review paper, scientists wrote that “a large number of studies have indicated that dietary supplementation of omega-3 fatty acids…may have the potential to prevent and reduce the complications of aging.” After carrying out their own research, their results on omega-3 “imply that it has the effect of anti-aging and preventing aging-related disease.”[20]
Are You Deficient? Low Omega-3 Symptoms
Research into the signs and symptoms of omega-3 deficiency is extremely limited and there’s no standard test for diagnosing deficiency. Studies have focused on the health benefits of increasing the intake of these fats in people with certain conditions. With that in mind, here is a list of possible deficiency symptoms.
Dry, irritated skin
A deficiency can cause rough, scaly skin and dermatitis, according to the National Institutes of Health.
A small randomized, double-blind 12-week intervention in women found that flaxseed oil, which is rich in ALA, led to significant decreases in skin sensitivity, moisture loss, skin roughness, and scaling, while smoothness and hydration were increased compared to those that took a placebo.[21]
Dermatologists also report fish oil helps patients with psoriasis.
Dry eyes
We’ve noted that omega-3 is important for eye health and low levels could give rise to dry eyes. A placebo controlled, double blind randomized trial involving 264 patients with dry eyes found after three months two-thirds of those taking a supplement containing EPA and DHA saw an improvement compared to one-third in the placebo group. [22] A second study also reported a benefit, but a third study of 349 patients over 12 months comparing fish oil with an olive oil placebo found no significant difference between the two groups.[23]
There are various reason why people suffer from dry eyes that may no be related to omega-3 so if you’re one of them you may wish to explore other natural ways to find relief.
Joint pain and stiffness
Many suffer these problems with aging and, as we’ve already noted, omega-3 can lower inflammation and may be helpful in the management of joint pain, stiffness and function.
Depression
Since omega-3 is important for the health of the brain, feeling depressed could be a sign of deficiency. A review covering 26 high quality studies and involving 2,160 participants found an overall beneficial effect of omega-3 polyunsaturated fatty acids on depression symptoms. [24] In another review of six studies which included 4,605 seniors, the researchers concluded that omega-3 fatty acids are effective in helping lift the moods of those with mild to moderate depression.[25]
Poor hair condition
Although many nutrients are needed for healthy hair, if it’s become dry, brittle, thin or is falling out, it could be a sign of omega-3 deficiency. A study of 120 women over six months found a combination of omega-3 and omega-6 reduced hair loss and improved hair density. [26]
Other health problems
Other conditions that could potentially be a sign of low omega-3 include liver problems, brittle nails, a constant buildup of earwax, poor sleep quality, impaired concentration, and fatigue.
Recommended Intakes
In the U.S., health authorities consider ALA to be adequate at 1.6 grams per day for men and 1.1 grams for women, but they offer no guidelines for EPA and DHA. Intake from foods is estimated from survey data to contribute about 90 mg to the daily diet.
Data from the 2011–2012 National Health and Nutrition Examination Survey (NHANES), showed the average daily ALA intake from foods in adults is 1.59 g in females and 2.06 g in males, thus meeting the guidelines. But a dietary analysis of 45,347 Americans published in 2019 found a low intake of omega-3 among the US population.[27]
The American Heart Association recommends eating two servings (6 ounces cooked) of fish, particularly fatty fish, each week to help reduce heart disease and stroke risk. If you have one glass of wine with your meal, this can supercharge the omega-3s in your food.
Ann Skulas-Ray, an assistant professor in the School of Nutritional Sciences and Wellness at the University of Arizona in Tucson, said, "Intakes [of EPA/DHA] in the U.S. are abysmally low. For the average person, taking dietary supplements is really correcting the nearly absent EPA and DHA in the American diet. Dietary supplements are a completely viable option for people who don't eat oily fish."[28]
Summary
Omega-3 is a key component of cell membranes and has multiple functions in the body. As the body can't make ALA it must come from food or plant oil supplements. EPA/DHA is produced in limited quantities from ALA and can only be obtained from eating fish or taking fish oil supplements or marine algae supplements. Omega-3 benefits the brain and eyes in particular, as well as other areas of the body and supports healthy aging. Shortfalls can lead to symptoms that show up in the skin, hair, eyes, joints and brain.
Frequently Asked Questions
What happens if your omega-3 is low?
Low omega-3 symptoms may show up as dry skin, dry eyes, weak hair, joint stiffness, fatigue, poor sleep, or depression.
Is there a downside to taking omega-3s?
It’s important to obtain fish oils from a reputable supplier to ensure they don’t contain contaminants or rancid oil. They may affect the stomach and cause burping in some people or leave a fishy aftertaste. They may also interact with blood thinning medications, giving an increased risk of bleeding. Speak to your healthcare provider if you have any concerns.
What's the best way to increase your omega-3 levels?
By eating foods rich in omega-3. The best way of obtaining ALA is by eating foods containing nuts, seeds, plant oils and pasture raised meats. The best way to obtain EPA and DHA is by eating oily fish. Non fish eaters can get EPA/DHA from fish oil or algae supplements.
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AHA News Are you getting enough omega-3 fatty acids? June 30, 2023
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