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Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...

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April 11 2018

How Ancestry Might Inform Your Fat Choices

By Mark Sisson
49 Comments

Inline_Ancestry Fat Choices.jpegOne of the more exciting developments over the past few years has been the explosion in population genetics research. People are a diverse lot, and even though we’re all people who essentially want the same things out of life (and we’re working with the same basic machinery), there’s a lot of wiggle room. It’s not just information for curiosity’s sake. The information researchers are uncovering about human ancestry can have real ramifications for how said humans should eat.

A couple years ago, I wrote a post laying out a few guidelines for using your personal ancestry to inform your diet. Today, I’m going to talk about another one: polyunsaturated fat metabolism.

For years, it’s been “common knowledge” in alternative health circles that most people just aren’t very good at converting the omega-3s (ALA) in plant foods into the long-chained omega-3s found in seafood (DHA, EPA), and that everyone should just eat fish for their omega-3s. This remains solid advice, but the reasoning needs a little tweaking. It turns out that the genes that encode the proteins responsible for conversion of ALA into DHA/EPA (and linoleic acid into arachidonic acid)—known as FADS—have a couple variants. Some variants make conversion less effective and some make conversion more effective. Furthermore, the distribution of these variants vary across populations.

For instance, the variant that increases conversion of ALA into DHA and EPA is more common in South Asian (Indian, Pakistani, Bangladeshi, Sri Lankan) populations and African populations than any other group, while it’s moderately common in Europeans and East Asians and rarest in Native Americans and Arctic natives. Why?

In Africa, anatomically modern humans initially crowded along the coasts because that’s where the food was, especially the omega-3-rich seafood that provided the nutrients necessary for brain expansion. When humans began expanding into the omega-3-deficient interior of the continent, those with the FADS gene variant for improved long chain PUFA conversion were more successful. They could live in areas totally bereft of marine foods and still make enough EPA and DHA to survive and produce big-brained babies. Researchers estimate that the new variant became entrenched in African populations around 85,000 years ago due to positive selection. To this day, African populations almost exclusively carry the variant that increases conversion.

Then, as modern humans left Africa and moved into Europe and Asia carrying that same genetic variant, they encountered new environments that placed new demands on their genes.

In South Asia, the gene variant persisted. Plants were plentiful and long-chained omega-3s were not due to warm water reducing the omega-3 content of marine life, and the ability to efficiently convert fats offered a survival advantage. About 3/4 of the population carries it today.

In East Asia, about 1/2 of the population carries it.

In Europe, meat and fish were more widely available. Conversion was less necessary when you had a regular intake of pre-formed EPA, DHA, and arachidonic acid. Thanks to European admixture with existing archaic populations who still had the conversion-decreasing variant, its frequency increased until the arrival of farmers from the East, whose agricultural innovations selected for and genes contributed to the conversion-increasing variant.

In Native American populations, including Arctic, North American, and Latin American natives, the variant is almost completely absent. They were getting all their long-chain PUFAs directly from animal and marine foods, and it shows in the genes.

That’s a broad overview. The story’s more complicated than that, of course. East Asia is a big place with many different ethnic groups. Same goes for Europe, and Africa, and everywhere else. Except for the Africans and Native Americans, the frequency of the variants vary within these populations.

In European populations, for example, the conversion-increasing variant has the strongest selection in southern European populations (Tuscans), slightly less strong selection in Iberian populations (Spain/Portugal), moderate selection in Britain and northern Europe, and the weakest selection in far northern Europeans (Finns).

The ancient European groups that fed into modern populations followed a similar north-south pattern of variance. West and Scandinavian hunter-gatherers in the north show the least selection for the variant, since the cold waters of northern Europe offered plenty of cold water fatty fish and elongation of plant omega-3s just wasn’t very helpful or necessary. Pastoralists and farmers to the south show the most selection.

What’s it all mean?

People with African ancestry are almost certainly homozygous (2 copies) carriers of the increased-conversion variant. South Asians, including Indians, Pakistanis, Bangladeshis, and Sri Lankans, are also strong candidates to be homozygous carriers. Southern Europeans are most likely heterozygous (1 copy) carriers, Western and Northern Europeans less so.

Indigenous ancestry (unless African) probably means you’re a carrier of the decreased-conversion variant. Alaskan or Greenland Inuit, American Indian, Mexican mestizo—they tend to have lower FADS activity due to the relatively recent inclusion of agricultural foods in their ancestral diets. The farther north your people hail from, the more likely you are to carry at least one copy of the decreased-conversion variant.

If you carry the FADS variant that increases conversion:

  • Watch your linoleic acid intake. A major reason linoleic—>arachidonic conversion was selected for was the rarity of both long-chain PUFAs and linoleic acid in the ancestral environment. Being able to convert all your linoleic acid to AA is great, assuming you’re not cooking with soybean oil, eating fries fried in corn oil, and snacking on potato chips in between meals. Seed oil high in concentrated linoleic acid is a historical aberration for everyone regardless of ancestry.
  • Don’t think you can skip the fish and start glugging flax oil just because your mom was Sri Lankan and your dad was Tuscan. Studies show that the benefits of long-chained omega-3s like DHA are not modified by FADS gene status. Everyone can benefit from fish. Some people just need it more.

If you carry the FADS variant that reduces conversion:

  • You need pre-formed DHA/EPA and arachidonic acid. You don’t make it very well. That means eating fish, shellfish, eggs, and other animal foods. Hard sell, I know.
  • And if you eat a ton of vegetable oil—as most people do these days—you’re in troubleResearch shows that people with the conversion-decreasing variant who eat a lot of linoleic acid have lower HDL, higher triglycerides, and a bigger waist than those who eat very little.
  • Your absorption and incorporation of DHA from food may be enhanced. One study in infants with the conversion-reducing variant found that taking fish oil increased DHA way more than in other babies. This could be a feature of infants with the variant—mom eats fish, passes DHA through breastmilk to baby, who absorbs every last drop—and not of adults.

Don’t know your FADS gene status? No problem. It’s actually more fun this way.

I would take the time to get your ancestry tested, unless you’re absolutely certain of your family tree—and it stretches far enough back to actually say something about your deep ancestry. That way you can look at the various populations from which you hail and make some educated guesses. And you can even plug the raw genetic data into a service that spits out your nutrition-and-health-related variants.

Even then, you may not get any hard and fast answers. FADS gene variant frequency data isn’t widely available for every possible ethnic group on Earth, so a lot of this is more art and intuition than hard science.

If the traditional diet of your immediate ancestry is plant-based—not vegan, just not buying steak from the non-existent grocery store—you probably carry at least one and perhaps two copies of the conversion-enhancing variant.

If your people lived near the sea or ate a decent amount of animal foods, you’re probably carrying one of the conversion-reducing variants.

Whatever you do, take it easy. Have fun with it. Very few people represent the tail end of an unbroken line of ethnic purity. Most people will vary a bit here or there, or a ton here and a ton there. I have a lot of Scandinavian ancestry, which explains my need for a lot of pre-formed DHA and EPA from wild seafood (I’ve confirmed with genetic tests).

As this topic is a moving target, with new data coming out constantly, I’ll probably revisit it from time to time. Until then, what do you all think about the field of ancestral influence and health? What’s your ethnic background, and what do you think it means for your ability to metabolize PUFA? And what other questions do you have regarding ancestry and diet?

Thanks for reading, everyone. Take care!

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49 thoughts on “How Ancestry Might Inform Your Fat Choices”

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  1. Fascinating. French, Danish and a little bit of Native American…guess I’ll have to keep eating lots of cold water fish and egg yolks…completely cool with that.

  2. Very interesting – I keep wavering on whether to order a testing kit or not (23andme or similar), so learning about these additional insights that may come from knowing those results is certainly tipping the scale in favor.
    As someone with eastern European ancestry (most of my modern ancestors hail from the Ukraine), there’s likely a mix of agrarian/horse – based nomad, and coastal cultures, not to mention some desert – dwellers farther back. Don’t know what that means for ideal omega-3 sources just yet, but luckily I’m a fan of both plant and animal options.

    1. Alisa, I’m fully Ukrainian and would love to hear anything you’e since discovered,

  3. Though I don’t know my gene status, I find the science of this fascinating! Reaffirms that even within paleo-primal, there’s no “one” optimal way of eating.

  4. Seems like a wide open field for further study. This ties in to some of the writings of Denise Minger in “Death by Food Pyramid”, like how much amylase different peoples have in their saliva. Can’t wait for some ground breaking work using our DNA.

  5. I am half native american and english and seem to definitely do well with the meat and I love my sardines! Never got into the flax yuckness. My kids are native and english and finnish, and they all loved their sardines when young. my baby twins have been paleo their whole life and are so strong and happy. haven’t done genetic testing yet

  6. ” And you can even plug the raw genetic data into a service that spits out your nutrition-and-health-related variants.”

    What services do this?

    1. I ran my data through Promethease.com. You get the raw data, but it’s easy to generate reports. There’s a drop down menu for diseases, so you can select, say, diabetes. If you can select, say, vitamin D. There’s also a search box into which you can type a search term. You can also select for only good genes, only bad, all, homozygosity or heterozygosity.

      I found that my geneset leads to low serum vitamin D, inefficient vitamin B12 recycling, and very hugh risk for diabetes. On the plus side, iI’m at low risk for heart disease when eating saturated fat, and I have an astounding cluster of genes associated with longevity! The latter is borne out by family history; my close relatives routinely live into their 90s, my paternal grandfather died at 104, and a great-great grandfather made it to 108! I also found the answer to why, since early childhood, I’ve been so easily physically fatigued – I’m homozygous for AMPD1.

      Promethease lets you save specific searches as pdf or Excel files, so you can create comprehensive personal reports.

      I’ll do the Found My Fitness for comparative purposes.

  7. This is a fascinating subject for me, I love ancestry studies, especially as it relates to nutrition, and I hope you delve into this even further in the future. I have (paternal) Polish and Balkan ancestry, and (maternal) Italian/French ancestry. I tend to favor meat and plants, and I use a lot olive oil, but I don’t do well on very high fat meals. I’m allergic to dairy. I don’t like fish, but I eat it for the nutrients. White potatoes are my weakness. How’s that for a mish-mash? 😉 I just purchased a Pathway Fit DNA test which will help determine my genetic diet type – well, at least that’s what they claim. We’ll see.

  8. Interesting topic! Do you know if there’s any evidence within an individual of downgrading or upgrading expression of these genes based on long-term dietary availability of source of PUFA? Is the inheritance of these genes Mendelian as you imply?

  9. Interesting. I’m mostly eastern european (the rest is western european), and my mDNA is from sublade T2 (agriculturalists), IIRC. Polish cuisine does feature a lot of meat, but also grains and veg. Maybe I’ll just try to eat more fish anyway instead of trying to draw conclusions where there is scarce data.

    1. Same here. My polish ancestors lived off mushrooms and game meat. Root veggies and barley and buckwheat. Fish was in the diet but not prominent. As time passes the food became very wheat oriented and more processed meats. I stick to shrooms and pig, cattle, some fish and bird. And lots of veggies. Fruits will typically be apples and peaches. Sometimes boiled. I feel great. Ice heard maple water also figured in polish prehistory.

  10. You Rock Mark! Thank you so much for being you. It has helped me and my loved ones. And your constant sharing of valuable information is so helpful and encouraging.

  11. I’m mostly Northern European, French and Native American. I feel the best, have the most energy, and get the best sleep eating similar to a Polynesian/tropical type diet. Seafood, chicken, tropical fruits, taro and sweet potato and LOTS of coconut.

  12. I think I read something from maybe Chris Kresser about how some people may react poorly to saturated fats due to their genetic make-up. Anyone have any info on this?

  13. 65% Celtic with only one copy of the FAD gene to turn walnuts and flax seed into usable EPA. I eat sardines, eggs, salmon – not much chicken or beef. FADS2 at rs1535. If you have A/A, you’re a high converter. As a G/G, my conversion rate is 29% lower. If you have A/G, as an interim converter, your rate is 18.6% lower

  14. I usually don’t pay attention to fads, but this one seems worthy of digging further!

    Dominant Native American genes here mixed with Western European, I understand better why I find seafood so satisfactory. Totally curious to go for genetic testing to know more about that aspect and all the other known ones, you got me convinced here Mark!

  15. I’m almost 100% southern Italian and I’ll say that after a ton of dietary experimentation, I feel my very best eating more fish and fresh produce, some (questionably paleo) legumes and doing without the amount of beef many Americans eat.

    1. To clarify: of southern Italian heritage. Not currently living in Italy.

  16. Eastern and Western European here, and who knows what else if you go back far enough. I know my immediate ancestors ate a lot of meat and potatoes. I often include seafood in my diet but also eat plenty of meat and veggies. I tend to prefer fatty meat over lean cuts. What I normally eat seems to work well for me so I don’t think I’ll be changing anything any time soon.

  17. If you have your FADS results, how do you interpret them? In other words, what gene (FADS1, FADS2, FADS3, etc.), marker (rs#), and genotype (A/A, G/G, etc.) are we looking for to determine our variant phenotype.

  18. I know in the 23andme blurb they indicate the fragments of DNA they look at are indicative of where your ancestors were 500 years ago. So you really need to do the testing, not just look at your family tree three generations back. I am a northern and eastern european mutt: great grandparents from Ireland, Poland, Germany and Czechoslovokia. Yet, according to 23andme, I had a ancestor from subsaharan Africa in the 1600s and spanish, Balkan and Italian ancestors from 1700s onward.

  19. Professor Mark, Thank You for providing insightful discussion on a topic that is confusing to many. I’m curious if these genetic variants have been studied in the Polynesian and Australian Aboriginal populations. It’s not as simple as access to food source, but may be influenced by access to sunlight and vitamin D source as well. You have investigated this in greater depth than I, but Ancestral Health concepts of one’s genetic makeup impacting metabolism of various nutritional components brings home the truth that there is no one size fits all diet. This could be controversial to the food pyramid pundits influencing health policy at the government level.

  20. Very interesting article- thanks! I’ve got results for 7 known FADS 1/FADS2 variants, I am homozygous for 6 of them (for the ‘risk’ allele) and heterozygous for 1 (1 risk allele, 1 normal). Lucky I love cold water fish, eggs etc. Might have to supplement DHA/EPA though.

  21. I’m South Asian and don’t do well (digestively) with a diet completely lacking in grains and legumes. I’ve also noticed that too much animal-based doesn’t work for me. I probably eat about 4-6 oz a day now, or less, and a much higher carb diet and seem to have finally found my sweet spot. Primal and paleo has taught me that refined flours, wheat and unfermented dairy are no good though, despite how common wheat based breads are in North Indian cuisine. Of course, selfishly, I’d love to know more about how people of South Asian descent seem to far on paleo/keto diets. My suspicion is not well, and I don’t know any Indian people who are straight up paleo/primal.

  22. A great post, Mark. A caveat: early human ancestors in Africa did not crowd along the coasts. The richest cluster of proto-humans occurs in the Wast African Rift Valley. If you look at a map of the sites, a lot of them are clearly far from the sea. Proto-humans clustered around sources of fresh water, as we need to drink a lot and often.

    Cumnane and Crawford, separately and together, argue for the importance of DHA and EPA in brain development in our evolution. However, they consider that aquatic animal sources are the key – whether those animals are marine, lacustrine, or riverine.

  23. I’m confused. I’m 75% Norweigan, the rest mixed european. My FADS (myrf) is homozygous. My genetic report says this variant has “higher than average levels of arachidonic acid, LDL and total cholesterol levels due to upregulated elongation of omega 6 PUFAs to pro-inflammatory compounds. Consider limiting sources of omega 6 PUFAs especially AA.”

    So this says PUFAs are bad for me because they are pro-inflammatory, but you are saying they aren’t bad because they get converted to Omega 3’s which are anti-inflammatory.

    Is this not the FADS gene you are talking about, but one of the others?

  24. Im not real good at researching this stuff…but I know my geography…so where on the African coast, near what is modern Ethiopia, did early humans (first mirgration) get cold water fish, high in Omega3s..? Plus, fishing is a hugely costly and difficult task…that does not always pay off with hugh dividends.

    It seems too simplistic to say humans clustered near the coasts, and therefore ingested Omega3s in sufficient brain expanding amounts. Am I, early human, gonna wade out into the oceans to maybe catch fish, and/or die, or go get that slower moving critter back here on land…? Hmm…

    1. I suspect ‘fish’ for these people included easy to gather clams, oysters, crabs, mussels, seabird eggs, etc. Not to mention taking advantage of schools of spawning shallow water fish which made gathering much easier. Sealife was plentiful even up to a couple of centuries ago.

  25. One thing that stands out to me reading the comments (especially as someone with some Native American genetics) is the number of commenters that also are part Native American. It stands to reason that we would be benefit disproportionately from a return to hunter-gatherer nutrient profiles. FWIW, I’m also of Polish, Dutch, and German extraction — lots of meat and veggies in these traditional diets as well!

    To this particular post more directly, it’s somewhat surprising to me that (unlike things like steak, bone broth, and leafy greens) I rarely crave fish and have to remember to eat it occasionally.

    I would love more posts along these lines — the post from a couple years ago has really influenced my thinking. Other topics that would be fun to analyze similarly would be salt (and other micronutrient) needs, tuber consumption (or more broadly, what’s the “best” carb source for people of different genetic backgrounds), best protein sources (I find myself flourishing eating red meat and eggs, but feeling rather lousy when I eat a lot of foul), and whether you’re genetically more likely to benefit from long term ketosis. To the last point, I’ve come to the conclusion (after much N=1 experimentation) that dipping in and out of the keto zone by cycling consumption of (cooked and cooled) tubers makes me feel the best — exactly as Mark suggests.

  26. Maybe one of the reasons I was always getting sick on a vegan diet. I am Finn, Swede, Welsh, Brit, Saxon, with some celtic Spanish thrown in. Fish has always felt right for me, and so has beef. For years I used to mix butter 50/50 with flax oil thinking I was doing a good thing. I think I’ll get tested; this article has made me curious. I have to find a way to share your article with some vegan friends without being offensive. Thank you for making this information understandable.

  27. Very cool post. Do you have preferences for sites that do genetic testing?

  28. My background is almost entirely southern European (with some eastern and central thrown in) – though my direct relatives are Italian, Central Euro and Puerto Rican (both grandparents). I have the AA variant (high-converter). Surprising given that most of my relatives would have lived near the ocean, for as far back as can be remembered.

  29. I love this! I recently had my DNA analyzed and similarly found that I do not convert plant omega 3s well. This makes sense and my ancestry is primarily Northwestern European.

    My biggest question regarding genomics and nutrition is that many of the health-evaluating programs that process your raw dna data include something called “saturated fat tolerance.” These analyses go so far as to say that I am more likely to gain weight with saturated and monounsaturated fat, and less likely to gain with polyunsaturated. I understand that much of their logic rests in the shady principles upheld by the AHA, but I am curious what your thoughts are on this, and what legitimate suggestions we can find in this analysis?

  30. I’m basically a western and northern European area mongrel: Scandinavian, Slavic, British. I think I should probably eat more fish. I confess to not spending very wisely. My meager money tends to go to unnecessary indulgences and I basically live out of dumpsters with a little Salvation Army food thrown in. I get wild caught mackerel from a dollar store sometimes though. $1.50 a can that’s 240g drained (of course I don’t waste the broth) – that’s not a bad deal. Please don’t jinx it! Seems like everything I buy ends up going in price.
    I wish we could actually italicize our words on this blog! It would increase our ability to express ourselves.
    And before I forget again, I’ve been thinking for a while that a glossary of acronyms and terms on this site would be a positive addition. For example, imagine someone relatively new to the field of primal research reading something like “I ate EVOO after my HIIT because I figured the MUFAs would balance my interleukin 6 and consequently reduce my DOMS”. Sounds kinda intimidating.
    And I said before that I suspected Mark was a Viking because of Norse references, repeated use of the word fjord, and appearance. I would also add the last name. I noticed that a lot of Scandinavian last names end in “son”, so Sisson would likely mean Sis’s Son. And I imagine that the i in Sis would have an accent on it, but I don’t know. I’m typing this comment in a rush, must take quick break from PC.

    1. Ah, finally found it. It’s not as easy to search for your old comments on MDA as it used to be. But I was chilling out with my bong yesterday, head in the clouds, and I decided I should define these abbreviations because I thought of another one and it reminded me of my previous comment.
      MDA: Mark’s Daily Apple, if you can’t figure that out.
      EVOO: extra virgin olive oil
      HIIT: high intensity interval workout
      MUFA: monounsaturated fatty acid
      (Plagiarized from google) Interleukin-6: (IL-6) is an interleukin that acts as both a pro-inflammatory cytokine and an anti-inflammatory myokine. In humans, it is encoded by the IL6 gene. (you’re going to have to look those other confusing words up yourself as I am not really sure what they are, do, or how they do it).
      DOMS: delayed onset muscle soreness (pain after exercise that you don’t feel until a while later)
      laboratory model: a hot scientist, or) a model grown in a laboratory. Either way, sounds good.

  31. I’ve been away from MDA for a while. Rejoining now because of this article. The world needs this sort of understanding.

    Forty some years ago I was 350 lbs and very unhappy, eating anything that wasn’t nailed down. I’m 70 now, and slim, fit, agile, and strong*! Mostly because of changing eating habits. Yes, working out / body care is equally as important; a body needs both.

    It’s been 5 years now that I’ve “stopped dieting” and truly cleaned up my earting act. I eat nothing processed), no added sugar (save a rare sample bite), drink no alcohol.

    I do eat:
    Sm amounts of low sugar fruit
    Veggies, raw or baked
    Fats: avocados, nuts, fish oils, coconut and olive oil (ok, those oils are processed)
    Protein: eggs, chicken, fish (mostly salmon), beef, protein powders (ok, that’s processed too!)
    That’s it.

    I’m 100% Scandinavian on mom’s side, German, Irish on dad’s. Dad lived to be 90. Mom is still cookin’ at 99. And both of them were NOT eating “well”, along with smoking and alcohol, but neither has/had diseases of any consequence. So I’m striving to protect the genetic gifts I’ve been given. Working out like a demon in order to have a strong body, should I live as long as mom. I almost ruined my gifts all those years ago, but am doing my best to maximize what I have.

    Glad to have rejoined MDA. An important tool on my Healthy Body Journey.

    * At 70, I’m training for deadlift competitions!! Gonna try to hit the Granny circuit! Having lots of fun!!!

  32. Love to read this informational article. It’s really good to know that our ancestry or genes are also responsible for our fat choices. Thanks, Mark, for sharing this awesome stuff.