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Fats & Omega-3
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In one pass Lard is solid at room temperature, olive oil flows, and fish oil is thinner still.
Educational content, not medical advice — consult a clinician.
Bile emulsifies → micrometer droplets Oil and water do not mix, so bile from the gallbladder acts like a detergent, emulsifying large oil droplets into micrometer-scale droplets that enzymes can reach.
Saturated only · stiff (lab membranes) The carbon chain of a saturated fatty acid (SFA) is straight — every C-C bond is single and rotatable, and the lowest-energy conformation is all-trans = a straight chain.
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Chapter 1
Three families
Lard is solid at room temperature, olive oil flows, and fish oil is thinner still. The difference is how many double bonds sit on the fatty acid's carbon chain — an extra link between two carbons. The more double bonds, the more the chain bends, the less tightly it packs, and the softer and more fluid the fat. That same structural difference also decides how each fat travels through the body.
By number of double bonds, dietary fats fall into three families:
Saturated fat — no double bonds. The chains are straight and stack neatly, so these fats tend to be solid at room temperature (coconut oil, animal fats, milk fat). They are chemically stable and slow to spoil, but eating a lot of them raises (the so-called bad cholesterol).Monounsaturated fat — one double bond, so the chain bends once (olive oil, avocado, nuts). It is the main fat of the Mediterranean diet and draws little dispute.Polyunsaturated fat — two or more double bonds, so the chain bends the most and is the softest (fish oil, flaxseed oil, sunflower oil). The more double bonds, the more easily it oxidizes, which is why flaxseed oil is a poor choice for high-heat stir-frying.
One more class, trans fat (mostly from partially hydrogenated vegetable oil), is the only one to avoid as far as you can. Processing straightens its chain like a saturated fat; it raises LDL and lowers (the so-called good cholesterol). The US Institute of Medicine (IOM) set no safe intake for it — only that less is better.
By number of double bonds, dietary fats fall into three families:
Saturated fat — no double bonds. The chains are straight and stack neatly, so these fats tend to be solid at room temperature (coconut oil, animal fats, milk fat). They are chemically stable and slow to spoil, but eating a lot of them raises (the so-called bad cholesterol).Monounsaturated fat — one double bond, so the chain bends once (olive oil, avocado, nuts). It is the main fat of the Mediterranean diet and draws little dispute.Polyunsaturated fat — two or more double bonds, so the chain bends the most and is the softest (fish oil, flaxseed oil, sunflower oil). The more double bonds, the more easily it oxidizes, which is why flaxseed oil is a poor choice for high-heat stir-frying.
One more class, trans fat (mostly from partially hydrogenated vegetable oil), is the only one to avoid as far as you can. Processing straightens its chain like a saturated fat; it raises LDL and lowers (the so-called good cholesterol). The US Institute of Medicine (IOM) set no safe intake for it — only that less is better.
Myth · Is coconut oil a superfood?
In the 2010s, coconut oil was marketed as a "healthy superfood." Here is the claim set against the evidence, point by point:Coconut oil is about 82% saturated fat (the figure the American Heart Association, AHA, gave in 2017), more than butter (about 60%) or lard (about 40%).Its most plentiful fatty acid is lauric acid, which has 12 carbons (written C12) and sits between medium and long chain.The AHA's 2017 advice: coconut oil raises and has no known benefit that offsets it, so the AHA advises against using it.A of clinical trials (Neelakantan 2020) found the same: compared with non-tropical vegetable oils, LDL was clearly higher on coconut oil, while markers of blood sugar, inflammation, and body fat showed no difference.
Another common claim is that "coconut oil is MCT (medium-chain ), so it's different." That is a misreading. Strictly speaking, MCTs are made of fatty acids with 8 and 10 carbons (C8 and C10). Coconut oil's main fatty acid, C12, is handled in the body more like a long-chain fat. Pure MCT oil (caprylic and capric acids) and coconut oil are two different things metabolically.
In practice:
Do not swap olive oil for coconut oil because of a "superfood" label.Cooking with coconut oil now and then (especially in Southeast Asian dishes) is fine, but it does not suit daily use as your main oil.For a daily main oil, prefer extra-virgin olive oil, avocado oil, tea-seed oil, or canola oil.Putting coconut oil on hair or skin is topical use and has nothing to do with the heart.
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Chapter 2
Two essential fatty acids
Mammals lack two enzymes (the Δ-12 and Δ-15 desaturases), so we cannot add a double bond at the omega-6 or omega-3 position of a fatty acid chain ourselves. The starting points of both lines must come from food, which is why they are called essential fatty acids:
Alpha-linolenic acid (, 18:3 omega-3) — from flaxseed, chia seeds, and walnutsLinoleic acid (LA, 18:2 omega-6) — from soybean, corn, and sunflower oils
Modern diets are rarely short of LA. One tablespoon of corn oil holds about 7 g of linoleic acid, close to half of an adult's daily adequate intake (US IOM: 12 g for women, 17 g for men). What is usually short is omega-3: most people eat little ALA, and even less of the long-chain omega-3s in fish ( and ).
Does a lot of omega-6 push up inflammation? By mechanism, arachidonic acid (AA), downstream of LA, is the raw material for some pro-inflammatory signaling molecules. But in randomized trials in healthy adults, eating more or less linoleic acid barely changed inflammatory markers in the blood (a systematic review, Johnson 2012). So the sounder move is to eat enough omega-3, not to fight omega-6.
Alpha-linolenic acid (, 18:3 omega-3) — from flaxseed, chia seeds, and walnutsLinoleic acid (LA, 18:2 omega-6) — from soybean, corn, and sunflower oils
Modern diets are rarely short of LA. One tablespoon of corn oil holds about 7 g of linoleic acid, close to half of an adult's daily adequate intake (US IOM: 12 g for women, 17 g for men). What is usually short is omega-3: most people eat little ALA, and even less of the long-chain omega-3s in fish ( and ).
Does a lot of omega-6 push up inflammation? By mechanism, arachidonic acid (AA), downstream of LA, is the raw material for some pro-inflammatory signaling molecules. But in randomized trials in healthy adults, eating more or less linoleic acid barely changed inflammatory markers in the blood (a systematic review, Johnson 2012). So the sounder move is to eat enough omega-3, not to fight omega-6.
Myth · Should you avoid omega-6 entirely?
"Omega-6 = pro-inflammatory = harmful" is a common oversimplification in nutrition media. Point by point:Linoleic acid (LA, omega-6) is an essential fatty acid; a long, complete lack of it causes dermatitis and poor wound healing.Most of the LA you eat goes into the phospholipids of cell membranes or is burned for energy.Only a very small share of LA is converted to arachidonic acid (AA), and AA is the raw material for pro-inflammatory signaling molecules such as prostaglandin E2 (PGE2). Eating more LA also does not push tissue AA up in proportion.In randomized trials in healthy adults, changing dietary linoleic acid barely changed inflammatory markers in the blood, such as C-reactive protein () and cytokines (a systematic review by Johnson and Fritsche, 2012).
What about the omega-6 : omega-3 ratio? The commonly quoted estimates are about 1:1 in ancestral diets and about 15:1 to 17:1 in modern Western diets (Simopoulos 2002). These are inferred numbers, from a narrative review that proposed the "ratio hypothesis." The two families really do compete for the same enzyme in the liver, so the ratio makes mechanistic sense. But when the European Food Safety Authority (EFSA) assessed dietary fats in 2010, it chose not to set a target ratio and gave absolute amounts for each instead. The back-and-forth over the ratio is covered in The Omega-6 : Omega-3 Balance. The more useful adjustment is to eat enough omega-3 (fish, ground flaxseed), not to force omega-6 down.
What is actually worth avoiding:
Trans fats (partially hydrogenated vegetable oils, now restricted or banned in many countries), the only class of fat with no healthy intake.Refined oils reused again and again at high heat (such as restaurant frying oil); the trouble is the oxidation products they form.Too much total energy: any fat, eaten in excess, gets stored.
In practice there is no need to avoid omega-6 entirely. Make olive oil or avocado oil (mostly monounsaturated) your everyday oil, use seed oils in moderation, and add fish and some ground flaxseed for omega-3. That is more useful than fussing over the ratio.
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Chapter 3
How fat is digested and absorbed
Fat does not dissolve in water, so after you eat it, it takes a special route:
1. The gallbladder releases bile. Bile acids emulsify big oil droplets into tiny ones, enlarging the surface the digestive enzymes can reach.
2. Pancreatic lipase, with its helper colipase, cuts into monoglycerides and free fatty acids.
3. Bile acids wrap these pieces into mixed micelles (small balls that can carry cargo through water) and deliver them to the surface of the small-intestine lining (the brush border).
4. Once absorbed, the gut cells reassemble the pieces into triglycerides and pack them into chylomicrons, large transport particles that also carry the fat-soluble vitamins A, D, E, and K.
5. Chylomicrons do not take the portal vein to the liver. They enter the lymph vessels first, travel up the thoracic duct, and join the blood where the left subclavian vein meets the internal jugular vein at the base of the neck.
That is why:
after a fatty meal, blood triglycerides take 3–4 hours to peak;a salad with no oil lets you absorb very little of its carotenoids — they have no ride;people who have had their gallbladder taken out often tolerate a very fatty meal less well.
1. The gallbladder releases bile. Bile acids emulsify big oil droplets into tiny ones, enlarging the surface the digestive enzymes can reach.
2. Pancreatic lipase, with its helper colipase, cuts into monoglycerides and free fatty acids.
3. Bile acids wrap these pieces into mixed micelles (small balls that can carry cargo through water) and deliver them to the surface of the small-intestine lining (the brush border).
4. Once absorbed, the gut cells reassemble the pieces into triglycerides and pack them into chylomicrons, large transport particles that also carry the fat-soluble vitamins A, D, E, and K.
5. Chylomicrons do not take the portal vein to the liver. They enter the lymph vessels first, travel up the thoracic duct, and join the blood where the left subclavian vein meets the internal jugular vein at the base of the neck.
That is why:
after a fatty meal, blood triglycerides take 3–4 hours to peak;a salad with no oil lets you absorb very little of its carotenoids — they have no ride;people who have had their gallbladder taken out often tolerate a very fatty meal less well.
Clinical · Fat absorption after gallbladder removal
Removing the gallbladder (cholecystectomy) is one of the most common abdominal operations. The gallbladder normally stores bile and squeezes it out in a burst after meals. Once it is gone, the liver still makes bile, but it now trickles into the gut continuously and in small amounts, without the "store it, then release it after a meal" rhythm.In the first weeks to months after surgery, the common patterns are:
After a very fatty meal (grilled meat, fried food, cream), there may not be enough bile to emulsify the fat fully, and some people get bloating or greasy stools.More common is bile acid diarrhea. With no gallbladder holding bile back, more bile acids flow straight into the colon and make it secrete water, which shows up as loose stools after meals. The treatment direction is a drug that binds bile acids, prescribed by a doctor — not extra bile. Over-the-counter ox bile supplements push in exactly the opposite direction.After a simple gallbladder removal, obvious fat-soluble vitamin deficiency is uncommon. If diarrhea does not settle or you are losing weight, see a doctor to find the cause.
Most people adapt gradually over a few months to a year after surgery, and fat absorption returns close to normal.
Practical advice:
In the first few months: eat smaller, more frequent meals, cut the fat in any single meal, avoid very greasy foods at first, and add them back step by step.If diarrhea after meals persists: ask a doctor whether it is bile acid diarrhea, and do not buy bile supplements on your own.Fish oil is still absorbed; taking it with meals in divided doses works better than one large dose.
Some groups have more serious fat malabsorption and need a doctor to monitor fat-soluble vitamins (A, D, E, and K — for example, regular checks of serum ) and essential fatty acids: chronic pancreatitis (not enough pancreatic lipase), cystic fibrosis (CF), short bowel syndrome, and severe Crohn's disease involving the ileum (the damaged ileum reabsorbs bile acids poorly).
Chapter 4
Cell membrane
Every cell (the human body has about 37 trillion) is wrapped in a phospholipid bilayer (lipid bilayer), so fat is not only fuel in storage but also building material. The key variable in the membrane is which fatty acids hang from the phospholipid tails:
with more saturated fatty acids and cholesterol, the membrane packs tighter and stiffer;with more polyunsaturated fatty acids (especially ), it is looser and more fluid, leaving the receptors and channels in it more room to move.
These rules were measured in cells and artificial membranes. Cells actively tune how stiff their membranes are, and how far everyday diet can push that has not been measured directly in people.
DHA, a long-chain omega-3, makes up ~50% of the phospholipid fatty acids in the membranes of the outer segments of retinal light-sensing cells, and about 15–20% of gray-matter phospholipids in the brain. That is the structural basis for research on omega-3, vision, and nerve development — not mysticism.
Membranes renew at very different speeds. The fatty-acid makeup of blood and red-cell membranes can follow a diet change within weeks to months (a red blood cell lives about 120 days); DHA in the brain turns over far more slowly, on a scale of years.
with more saturated fatty acids and cholesterol, the membrane packs tighter and stiffer;with more polyunsaturated fatty acids (especially ), it is looser and more fluid, leaving the receptors and channels in it more room to move.
These rules were measured in cells and artificial membranes. Cells actively tune how stiff their membranes are, and how far everyday diet can push that has not been measured directly in people.
DHA, a long-chain omega-3, makes up ~50% of the phospholipid fatty acids in the membranes of the outer segments of retinal light-sensing cells, and about 15–20% of gray-matter phospholipids in the brain. That is the structural basis for research on omega-3, vision, and nerve development — not mysticism.
Membranes renew at very different speeds. The fatty-acid makeup of blood and red-cell membranes can follow a diet change within weeks to months (a red blood cell lives about 120 days); DHA in the brain turns over far more slowly, on a scale of years.
Mechanism · How membrane fluidity affects receptors
Membrane fluidity describes how freely molecules can move within a membrane. Receptors, ion channels, and transporters sit in the membrane and have to change shape to work, so how stiff or soft the membrane is affects them. What follows comes mainly from experiments in cells, artificial membranes, and animals:A stiffer membrane (more saturated fatty acids and cholesterol):
G-protein-coupled receptors (GPCRs, the largest family of receptors on the cell surface) signal more weakly;ion channels open and close more slowly;rods and cones respond to light more sluggishly;vesicle fusion at nerve synapses slows.
A softer membrane (more polyunsaturated fatty acids, especially ):
DHA carries 6 cis double bonds, which twist its tail into a spiral that cannot pack tightly, so the membrane is highly fluid;in the outer-segment membranes of retinal light-sensing cells, DHA makes up about 50% of the fatty acids in phosphatidylethanolamine, which helps rhodopsin reset quickly after it absorbs light;some researchers think the activity of AMPA and NMDA receptors in synaptic membranes also depends on DHA-rich membrane microdomains (lipid rafts); this is still being studied.
Evidence in people:
Low DHA during pregnancy and infancy is associated with lower scores for visual development and cognition (an observed association). This is part of the background for adding DHA to infant formula, which is now widespread.Age-related macular degeneration (AMD, a common cause of vision loss in older people): in AREDS2, a large randomized trial, adding DHA and to the existing supplement formula did not further reduce progression to advanced AMD.Multiple sclerosis, depression, and bipolar disorder: there is plenty of research on membrane fatty-acid status, but randomized trials disagree, and any benefit is small.
In practice: membrane composition shifts slowly with diet, but there is currently no evidence that eating more DHA improves membrane function that is already normal. You do not need to count DHA milligrams each day; 2–3 fatty-fish meals a week, or algae oil, is enough.
areds2-2013-jama
Chapter 5
Three kinds of omega-3
Omega-3 is not one thing but a family of three:
(alpha-linolenic acid, 18:3) — from plants (flaxseed, chia seeds, walnuts) (20:5) — can be made into signaling molecules that help inflammation wind down (E-series resolvins) (22:6) — structural fat of the brain and retina; it can also be made into D-series resolvins and protectins
The body can convert ALA into EPA and then DHA, but only through a string of enzymes (Δ-6 desaturase, an elongase, Δ-5 desaturase, two more elongations, a second pass through Δ-6, and a final trim), and the first one, Δ-6 desaturase, is also claimed by omega-6 linoleic acid. The result (a review by Burdge and Calder, 2005):
ALA to EPA: about 5–10% (a bit higher in women, linked to estrogen)ALA to DHA: often under 1%
So eating lots of flaxseed is not a reliable way to get DHA. For vegetarians and vegans who want EPA and DHA, algae oil (microalgae make DHA themselves) is the direct source; for people who eat fish, two fatty-fish meals a week are usually enough (for example see Salmon, see Sardines, herring, or mackerel).
(alpha-linolenic acid, 18:3) — from plants (flaxseed, chia seeds, walnuts) (20:5) — can be made into signaling molecules that help inflammation wind down (E-series resolvins) (22:6) — structural fat of the brain and retina; it can also be made into D-series resolvins and protectins
The body can convert ALA into EPA and then DHA, but only through a string of enzymes (Δ-6 desaturase, an elongase, Δ-5 desaturase, two more elongations, a second pass through Δ-6, and a final trim), and the first one, Δ-6 desaturase, is also claimed by omega-6 linoleic acid. The result (a review by Burdge and Calder, 2005):
ALA to EPA: about 5–10% (a bit higher in women, linked to estrogen)ALA to DHA: often under 1%
So eating lots of flaxseed is not a reliable way to get DHA. For vegetarians and vegans who want EPA and DHA, algae oil (microalgae make DHA themselves) is the direct source; for people who eat fish, two fatty-fish meals a week are usually enough (for example see Salmon, see Sardines, herring, or mackerel).
In practice · How to pick a fish-oil supplement
The Fish Oil and algae-oil supplement market is a mixed bag, but three numbers are enough to navigate it. More on forms and freshness is in Fish Oil · / Supplements.1. The actual EPA plus DHA content (not "fish oil 1000 mg")
"1000 mg fish oil" on a label is not 1000 mg of omega-3. A typical ordinary capsule holds only 180 mg of EPA plus 120 mg of DHA, 300 mg in total. Look at the EPA and DHA milligrams per serving; their sum is what you actually get.
2. Oxidation
The polyunsaturated double bonds in fish oil oxidize very easily, and in fish oil that has gone off, part of the EPA and DHA is already damaged. The industry body GOED (Global Organization for EPA and DHA Omega-3s) sets a total oxidation value (TOTOX) below 26 as its standard. Open the bottle and smell it: a strong fishy smell usually means it has oxidized. Capsules are more stable than liquid; refrigerate after opening.
3. Form
Natural (TG): the form fish carry naturally.Re-esterified triglyceride (rTG): purified and concentrated, then put back on a triglyceride backbone; most mainstream high-strength products are this form.Ethyl ester (EE): the product of industrial distillation and concentration, and cheap. Taking it with a meal that contains fat improves absorption somewhat.Phospholipid form (krill oil): EPA and DHA are attached to phospholipids, with natural astaxanthin. Each capsule holds little and costs a lot; makers say it absorbs better, but there are not enough head-to-head studies.
In the Dyerberg 2010 trial (72 volunteers, about 3.3 g of EPA plus DHA a day for 2 weeks), with natural fish oil set at 100%, bioavailability was 124% for rTG and 73% for EE.
Dose guide
General health: 250–500 mg of EPA plus DHA a day (roughly what 2 fatty-fish meals a week provide).Existing coronary heart disease: the American Heart Association (AHA) advises about 1 g of EPA plus DHA a day.Very high triglycerides (> 500 mg/dL): 2–4 g a day, a prescription dose that a doctor decides on.Pregnancy and breastfeeding: at least 200 mg of DHA a day.Inflammatory and autoimmune conditions: doses are higher and the evidence is less consistent than for lowering triglycerides, so use it under a doctor's guidance.
Safety
The safety reference usually quoted from the US FDA is 3 g a day of EPA and DHA combined. It is the intake ceiling the FDA used when it classed fish oil as generally recognized as safe (GRAS), not a formal Tolerable Upper Intake Level (). The higher the dose, the more care bleeding deserves: if you take warfarin, aspirin, or another anticoagulant or antiplatelet drug, tell your doctor before adding fish oil. Stopping it before surgery is a common, cautious practice.
Vegetarians and vegans can use algae oil. It provides DHA directly and contains no mercury, but it is usually lower in EPA and costs more.
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Chapter 6
This week: three habits
Three habits that are more useful than memorizing milligrams:
1. Two fatty-fish meals a week — salmon (see Salmon), trout, sardines (see Sardines), herring, mackerel. One 100–150 g portion carries roughly 1–2 g of plus , along with vitamin D and good-quality protein.
2. Cook mainly with olive oil or avocado oil — both are mostly monounsaturated fat and hold up fairly well to heat. Soybean, sunflower, and corn oil need no special avoiding either: the American Heart Association (AHA) advises using exactly these unsaturated vegetable oils in place of saturated fat.
3. Sprinkle a small handful of ground flaxseed, chia seeds, or walnuts on breakfast — a backstop for . Flaxseed must be ground: the whole seed has a hard coat, and much of it passes out in the stool intact.
Do these three and the omega-6 : omega-3 ratio falls on its own. But the European Food Safety Authority (EFSA) sets no ratio to hit; it gives amounts for each (for example, about 250 mg of EPA plus DHA a day for adults). So eating enough omega-3 is far more useful than chasing a ratio or counting EPA milligrams.
1. Two fatty-fish meals a week — salmon (see Salmon), trout, sardines (see Sardines), herring, mackerel. One 100–150 g portion carries roughly 1–2 g of plus , along with vitamin D and good-quality protein.
2. Cook mainly with olive oil or avocado oil — both are mostly monounsaturated fat and hold up fairly well to heat. Soybean, sunflower, and corn oil need no special avoiding either: the American Heart Association (AHA) advises using exactly these unsaturated vegetable oils in place of saturated fat.
3. Sprinkle a small handful of ground flaxseed, chia seeds, or walnuts on breakfast — a backstop for . Flaxseed must be ground: the whole seed has a hard coat, and much of it passes out in the stool intact.
Do these three and the omega-6 : omega-3 ratio falls on its own. But the European Food Safety Authority (EFSA) sets no ratio to hit; it gives amounts for each (for example, about 250 mg of EPA plus DHA a day for adults). So eating enough omega-3 is far more useful than chasing a ratio or counting EPA milligrams.
In practice · Choosing low-mercury fish
When "eat more fish" meets real life, the most common worry is mercury (methylmercury) contamination.High-mercury fish (pregnant or breastfeeding women, women who may become pregnant, and children should avoid them): shark, swordfish, marlin, king mackerel, tilefish from the Gulf of Mexico, orange roughy, and bigeye tuna. The joint fish advice from the US Food and Drug Administration (FDA) and the Environmental Protection Agency: do not eat these fish during pregnancy or breastfeeding, or in childhood.
Medium mercury (limit them): canned albacore (sold as white tuna), with about 3 times the mercury of canned light tuna; halibut; and some bass. During pregnancy, eat this group only in limited amounts.
Low in mercury and rich in omega-3 (recommended):
Salmon (wild or farmed)Sardines and anchovies: small and short-lived, so they build up little mercury, and they are high in omega-3. Eaten with the bones they add calcium, plus vitamin D and B12.HerringFarmed troutCanned light tuna (mostly skipjack): about a third of the mercury of canned albacorePacific cod
Sustainability and the environment:
Choose products with a sustainability certification (MSC, ASC).Avoid overfished species (bluefin tuna, swordfish).Farmed and wild each have trade-offs: the omega-3 content of farmed fish varies with its feed, and contamination is easier to control. Prefer certified farmed fish.
In pregnancy: eat 2–3 servings of low-mercury fish a week (8–12 oz, about 230–340 g), and you can add 200–300 mg of algae-oil a day as a backup. Do not give up fish entirely out of fear of mercury: for the fetal brain, eating low-mercury fish does more good than harm overall, which is the core message of the FDA and Environmental Protection Agency fish advice.
Vegetarian and vegan alternatives:
Microalgae DHA supplements: DHA directly, no mercury, and a small environmental footprint.Flaxseed, chia seeds, and walnuts: they provide , but only a small share is converted to and DHA.
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References · 8
- Sacks, F. M., Lichtenstein, A. H., Wu, J. H. Y., Appel, L. J., Creager, M. A., Kris-Etherton, P. M., et al. (2017). Dietary fats and cardiovascular disease: A presidential advisory from the American Heart Association. Circulation, 136(3), e1-e23. Coconut oil is ~82% saturated; the AHA advises against its use because it raises LDL-C with no known offsetting favorable effect, and recommends replacing saturated with unsaturated fat. 10.1161/CIR.0000000000000510
- Institute of Medicine. (2005). Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press. nap.nationalacademies.org/catalog/10490/dietary-reference-intakes-for-energy-carbohydrate-fiber-fat-fatty-acids-cholesterol-protein-and-amino-acids
- Mozaffarian, D., & Wu, J. H. Y. (2011). Omega-3 fatty acids and cardiovascular disease: effects on risk factors, molecular pathways, and clinical events. Journal of the American College of Cardiology, 58(20), 2047–2067. 10.1016/j.jacc.2011.06.063
- Johnson, G. H., & Fritsche, K. (2012). Effect of dietary linoleic acid on markers of inflammation in healthy persons: a systematic review of randomized controlled trials. Journal of the Academy of Nutrition and Dietetics, 112(7), 1029-1041. Across 15 RCTs in healthy non-infant adults, altering dietary linoleic acid produced virtually no change in inflammatory markers (CRP, fibrinogen, PAI-1, cytokines, soluble adhesion molecules, TNF-α). 10.1016/j.jand.2012.03.029
- National Institutes of Health, Office of Dietary Supplements. (2023). Omega-3 Fatty Acids — Fact Sheet for Health Professionals. ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional
- Burdge, G. C. (2006). Metabolism of α-linolenic acid in humans. Prostaglandins, Leukotrienes and Essential Fatty Acids, 75(3), 161–168. Conversion of dietary ALA is limited; the 2002 young-women / young-men tracer papers are different studies (EPA ~21% / DHA ~9% in women; little DHA enrichment in men) and are not this record. 10.1016/j.plefa.2006.05.013
- Burdge, G. C., & Calder, P. C. (2005). Conversion of alpha-linolenic acid to longer-chain polyunsaturated fatty acids in human adults. Reproduction, Nutrition, Development, 45(5), 581-597. Conversion of dietary ALA to EPA is limited (~5-10%) and conversion to DHA is very low (often <1%), so plant ALA cannot substitute for the EPA/DHA in fish. 10.1051/rnd:2005047
- EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA). (2010). Scientific Opinion on Dietary Reference Values for fats, including saturated fatty acids, polyunsaturated fatty acids, monounsaturated fatty acids, trans fatty acids, and cholesterol. EFSA Journal, 8(3), 1461. The Panel proposed not to set a Dietary Reference Value for the n-3/n-6 ratio, instead setting Adequate Intakes for linoleic acid (4% of energy), α-linolenic acid (0.5% of energy), and EPA+DHA (250 mg/day for adults). 10.2903/j.efsa.2010.1461