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Nov 21, 2020

After publishing my recent giant fish oil article "A Deep "Dive" Into The Fascinating World Of Fish Oil, The Right Fat Ratios In Your Diet, Plant Vs. Animal Based Oils & The Exact Fish Oil Ben Greenfield Uses Every Day.", I've been getting plenty of questions about fish oil lately, including:

-Based on human clinical research, what are the actual proven benefits of fish oil?

-What kind of dosages/types of fish oil were used in studies?

-Are there concerns about rancidity/oxidation when taking fish oil?

-What kind of amount and EPA/DHA ratio is ideal?

-Are there people who shouldn't take fish oil?

-Are there certain nutrients or supplements that should be taken with fish oil?

-How can one test their omega fatty acid status?

And much more.

So I finally decided to get a couple of true, unbiased fish oil experts on my show.

Dr. William S. Harris is my first guest. He is an internationally recognized expert on omega-3 fatty acids and how they can benefit patients with heart disease. He obtained his Ph.D. in Human Nutrition from the University of Minnesota and did post-doctoral fellowships in Clinical Nutrition and Lipid Metabolism with Dr. Bill Connor at the Oregon Health Sciences University.

His interest in omega-3 fatty acids began with his postdoctoral work when he published his first study on the effects of salmon oil on serum lipids in humans (1980). Since that time he has been the recipient of five NIH grants for studies on the effects of omega-3 fatty acids (EPA and DHA) on human health. He has more than 300 publications relating to fatty acids, including omega-3s, in medical literature and was an author on two American Heart Association scientific statements on fatty acids: “Fish Consumption, Fish Oil, Omega-3 Fatty Acids and Cardiovascular Disease” (2002), and “Omega-6 Fatty Acids and Risk for Cardiovascular Disease” (2009) both published in the journal Circulation. Dr. Harris is a Professor in the Department of Medicine in the Sanford School of Medicine at the University of South Dakota and the President and CEO of OmegaQuant.

Dr. Harris's daughter, Dr. Kristina Harris Jackson, PhD, RD is my second guest. Kristina received her PhD in Nutritional Sciences from Pennsylvania State University in 2013 and completed her training to become a Registered Dietitian in 2014. As a graduate student, she studied under Dr. Penny Kris-Etherton, an internationally-recognized expert in fats and nutrition. She worked as a postdoctoral fellow at the University of Colorado-Denver under Dr. John Peters in the area of worksite wellness before returning to the omega-3 field. Kristina joined the family business OmegaQuant Analytics as a Research Associate in 2014, with a particular focus on omega-3s in maternal health, helping create the Prenatal DHA test and the Mother’s Milk DHA test. In 2020, she became Assistant Professor (non-tenure) in the Department of Internal Medicine at the University of South Dakota Sanford School of Medicine. (2020-2022). She lives in Sioux Falls, South Dakota with her husband, two kids, one old dog, and four grandparents.

During this discussion, you'll discover:

-The 2 sources of Omega-3 fatty acids...8:35

  1. Plant derived fatty acid ALA, alpha linolenic acid( 18 carbons); an acid in the omega-3 family – not the same thing as the fish derived omega-3
  2. Fish derived EPA (20 carbons) and DHA (22 carbons)
  • Cannot get much of the good stuff from ALA (seeds and nuts)
  • Algal oil from micro algae (single cell organism, not kelp) that make EPA/DHA naturally; at the base of the marine food chain
    • Omega-3 fatty acids are made by plants, not fish
  • Some companies grow these algae in big ponds, harvest the omega-3 fatty acids and put in capsules
    • Vegan derived EPA/DHA products has exactly the same molecules as EPA/DHA derived from fish, but does not come from fish, it comes from algae
    • Process is expensive
  • Aquaculture industry is driving the demand for algal oil
    • 70~80% of fish oil produced is fed back to the fish
  • Other sources of fish oil are genetically modified land plants
    • Canela seed oil; Australia is at the forefront to put genes into oil producing land plants, like soy beans

-What makes essential fatty acids so essential...15:45

  • Cell membranes, made up of fatty acids, surround every cell in the body
    • For structural aspect of the cell
    • Provides starting products for different signaling pathways, affects how cells communicate internally and externally
    • Membrane fluidity; more carbon and double bonds makes cell membranes more flexible and fluid
  • Cell membranes are comprised of dietary fats
    • The body can’t make the essential omega-6 fatty acids (linoleic) and omega-3 fatty acids(ALA and EPA/DHA); these comes from the diet
    • Trans-fats are also dietary fats
  • Other fats, like saturated fats and monounsaturated fats, are affected by metabolism

-Omega-3 fatty acids being oxidized once it enters the body is a misconception...19:36

-Ratio of omega fatty-acids in the body and what the ratios should be...25:32

  • Good ratio of EPA to DHA is when eaten in fish
    • EPA taken alone increases EPA and decreases DHA a little bit; increased omega-3 index - the measure of EPA/DHA in red blood cells (RBC)
    • Pure DHA taken alone increases both EPA and DHA in RBC
    • DHA is the predominant omega-3 fatty acid in membranes
    • 85% DHA to 15% EPA in RBC
    • In fish oil, total dose (EPA+DHA) is the important thing
    • A study found the ideal optimum fatty acid levels (EPA+DHA) to be 8~12% index
  • Ratio of omega-6 to omega-3

-Ethyl Ester and Triglyceride forms of Omega-3 fatty acids...33:20

  • Different ways Omega-3 fatty acids are processed and concentrated
    • Ethyl ester is the first highly concentrated form; first to be concentrated into a capsule
    • Triglycerides form is the more natural form (how it would be present in the fish)
  • Most fish oil supplements in the U.S., if it does not say it is in triglyceride form, is an ethyl ester
  • No standardized way to know if it is triglycerides or ethyl ester
  • Biggest difference as far as bioavailability goes is if supplements are taken with meals
    • Ethyl esters, if taken without a meal might not be absorbed at all; absorbed well if taken with a meal, preferably a meal that contains fats
    • Triglycerides are not affected by that meal component as ethyl esters
  • All pharmaceutical brands of fish oil are ethyl esters
    • More EPA and DHA molecules in a 1 gram capsule if in ethyl ester form
  • Distinction only came up around 15 years ago when ethyl ester form of fatty acids was seen as not well absorbed by the body when taken on an empty stomach
    • Taking ethyl ester form supplements without food might not get the desired omega-3 index result

-What genes convert ALA or plant-based oil into EPA/DHA...45:15

  • Genetic conditions that affect omega-3 fatty acid levels
    • FADS genes produce the enzymes that convert ALA to EPA and DHA
    • Enzymes also convert linoleic acid to arachidonic acid (polyunsaturated omega-6 fatty acid)
  • Natural variations by populations in the kinds of mutations that are present in the FADS genes can affect levels, particularly of arachidonic acid
  • Omega-3 EPA/DHA are not much affected by the FADS genes
  • Major genetic effect driving omega-3 levels in the population is not known
  • Is there a genetic effect on the absorption of omega-3 in the population?
    • No study on why a certain population has a huge absorption response while in another population, there is hardly any response
  • Nomenclature:
    • Omega-3 ­– a fatty acid where the 1ˢᵗ double bond counting from the omega carbon is in the third position
    • Omega-6 – a fatty acid where the 1ˢᵗ double bond counting from the omega carbon is in the sixth position
  • Cannot be inter-converted
  • Plants can convert omega-6’s into omega-3’s, animals cannot

-Ratio of omega-6 to omega-3 fatty acids...52:17

  • “Ratio of omega-6 to omega-3” is imprecise – it’s not clear what type omega-6 or omega-3 is referred to; for example, there are 7 omega-6 fatty acids in the blood
    • It also presumes that ALA and EPA/DHA have the same biologic activity or they have the same value when they do not
    • The same is also true on the omega-6 side
  • To say “total omega-6 to total omega-3 ratio” would also be confusing; it does not say what type fatty acids are there; it does not tell anything about it's effect on health - some fatty acids are beneficial and some are not
  • You can have very high levels of omega-6 and omega-3 in your blood, or you can have very low levels, and yet have the same ratio
  • It also presumes that all omega-6’s are bad and all omega-3’s are good, which is not true
    • Omega-3 fatty acids being good is not questionable
    • What’s questionable is the goodness or badness of omega-6’s; linoleic acid is not made in the body and has to be eaten
    • Studies have shown that high levels of linoleic acid in the blood always predict lower incidence of heart disease and diabetes, and conversely
  • Focus on the omega-3 index is that EPA/DHA are what is missing in our diets; there are plenty of omega-6’s

-Link between Omega-6 and inflammation and chronic disease...1:00:18

  • High consumption of oxidized PUFAs , primarily found in vegetable oils which are high in omega-6 fatty acids
  • Omega-6 fatty acid that gives rise to eicosanoids in the inflammatory pathway is Arachidonic acid, a synthetic product of linoleic acid
  • Eicosanoids is associated with increased incidence of inflammation and chronic diseases like arthritis, cancer, etc.
  • Synthesis of arachidonic acid is very regulated; tissue levels remain the same regardless the amount of linoleic acid consumed, to a point (it eventually runs out if linoleic acid consumption is stopped)
  • Higher levels of linoleic acid in the blood means you are eating more of it, which comes from vegetable oil; the only way to get high levels in your blood is to eat more
  • For heart disease and diabetes, higher levels of linoleic acid is good for the heart and metabolism; less people develop these diseases if they have high levels of linoleic acid
  • The best way to decrease the ratio is to increase your omega-3 side; by increasing EPA/DHA, EPA replaces, to some extent, the arachidonic acid
    • Having more long-chain omega-3 in the membranes lowers omega-6, correcting the proportion

-Contaminants in fish oil, cleanliness, sourcing, concerns about packaging, shelf life, heat exposure during the manufacturing process...1:06:13

-And much more!

Resources from this episode:


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Do you have questions, thoughts or feedback for Dr. Harris or me? Leave your comments below and one of us will reply!