Can a Low-Carb American Diet Cause Omega-3 Deficiency?
tl;dr: It would be nice if our food supply was trustworthy.
Dr. Michael Eades has done a number of posts recently about seed oils:
I thought I would do one about him.
I’ve had the privilege to meet him in person, and share a meal with him and our wives, at the AHS 2021 seminar where we both gave talks.
He’s a very smart guy. He’s one of the most knowledgeable people I know in the nutrition space, and has been one of the leaders of the low-carb community for decades.
He’s also very successful, and, to infer from the lifestyle comments he makes on his blog/newsletter The Arrow, can likely afford to eat as well as he thinks is necessary for his and his wife’s health (her nickname is “MD”).
Ω-3 Deficiency
So I was pretty surprised to read this:
“I have had a couple of problems I’ve been battling. One is a terrible itch on my back and the cheeks of my rear end. I’ve written it off to the dry skin of old age. MD keeps telling me to put some kind of skin conditioner on my back and butt, but I just don’t want to oil myself up. So I don’t. I also have mild back pain, probably from golf and doing dead lifts with the bands. My back is ancient and has suffered a lot of abuse over my fairly active life.”
Itchy skin (dermatitis) is a classic sign of essential fatty acid (EFA) deficiency. Ralph Holman was one of the more productive researchers in this area. He invented the Ω terminology we use to describe these fats, and described the first reported case of Ω-3 deficiency in a human being (Holman, 1982).
He described a “severe dermatitis of deficiency” which appeared when rats were made deficient in essential fats.
“When such rats were supplemented with marine (fish) oils, remarkable cures of dermatitis took place although such oils do not show curative activity in the usual assay.” (Holman, 1971)
For many decades it was thought that only rodents were subject to EFA deficiency, but the development of total parenteral nutrition (TPN), which was initially a fat-free formulation, proved that humans are susceptible to EFA deficiency too. A totally fat-free diet (the ultimate ultra-processed diet) induces “skin lesions” or “dermatitis” in a month or three.
Dr. Eades will be happy to hear that therapeutic administration of corn oil to the skin was ineffective: you are better off eating your ‘skin lotion’ (not literally) than applying it topically (Holman, 1998).
“MD and I started the sardines once a day and the flaxseed oil salad dressing with every meal, and my itching vanished within a week. I kid you not. And my back pain is all but gone.”
Sardines, of course, contain the animal-based Ω-3 fats we actually need; flaxseed oil contains plant-based Ω-3 fats that we can convert to the animal-based ones. Somewhat. See the FADS research below.
So that, to me, seems to be a pretty clear case of a deficiency which is immediately cleared up by curing the deficiency. Dr. Eades seems to think the same.
“So, in the words of the famous Monkee’s song, ‘now I’m a believer. Not a trace of doubt it my mind.’ Just adding that bit of omega-3 to my diet has paid huge dividends…. I do know it got rid of my chronic itch and my back pain and did so quickly.”
And yes, there’s good reason to think the back pain was the same issue. That’s fuel for another post, but I discussed it here: “Linoleic Acid and Pain”.
Seed Oils and Low-Carb
I’ve often said that I think a good amount of the beneficial effect of a low-carb diet is due to the restriction of seed oils that comes with reducing carbohydrates in ultra-processed foods.
For instance, potatoes fried in seed oils (chips or French-fried) cause obesity, potatoes without seed oils do not.
Dr. Eades’ experience suggests that his low-carb diet has successfully reduced his seed oil intake, and with it his intake of plant-based Ω-3 fats. Soybean and Canola oils are the most common seed oils in the American diet, and have substantial amounts of plant-based Ω-3 fats. For most Americans I suspect those two oils are their primary source of Ω-3 fats. The girl in (Holman, 1982) had her severe Ω-3 deficiency cured with soybean oil.
However, plant-based Ω-3 fats aren’t a substitute for the animal-based variety (Wien, 2010). As in that RCT, eating plant-based Ω-3 fats could have left Dr. Eades with a deficiency, since they do not allow the body to make all the Ω-3 fats it needs. The vegetarians in (Wien 2010) were not able to make DHA from plant-based Ω-3.
How To Get Ω-3
So Dr. Eades, who can eat whatever he would like (I presume), wound up with a deficiency by eating a low-carb, somewhat-processed diet.
“Until I became sensitized to the whole ultra-processed foods idea, I’ve got to admit that I simply looked at the carb content on food labels. I simply read what was in whatever food I was considering in terms of actual food content and completely ignored all the chemicals, gums, preservatives, etc at the bottom of the list of ingredients.”
I presume (I’m doing a lot of that) that means he was eating industrial beef, chicken, and pork, and evidently not enough fish. As Prof. Hulbert notes, that’s a diet that’s deficient in Ω-3.
I have long maintained that fish should not be necessary for a healthy diet. Most of the people in Africa, where we evolved) do not have access to seafood, due to the geography of the continent.
The same is true for every other landmass. If you’re a paleolithic hunter-gatherer, you never popped down to the fish store to buy some for dinner, and it was usually too far a walk to go fishing.
So clearly we had some other way to get it, and that must have been from eating game that fed on leaves and had ample Ω-3 fats, enough to allow us to evolve our large brains.
“The Fat from Frozen Mammals Reveals Sources of Essential Fatty Acids Suitable for Palaeolithic and Neolithic Humans.” (Guil-Guerrero, 2014)
Is Grass-fed Sufficient?
Dr. Eades read Omega Balance recently, and reviewed it in Arrow #202.
He notes a problem with getting enough Ω-3 from modern industrially-raised animals. Is the USDA perpetrating a grass-fed fraud?
“The U.S. Department of Agriculture’s standard for a ‘grassfed’ beef animal is that it be 50% grass-fed.”
WHAT!?!
DRAT. This is very upsetting. But luckily it’s not quite accurate.
The source for this claim is a South Dakota State University Extension website (Bauman, 2021), from which comes the quote above, that ‘grassfed’ means only 50%.
“Information provided in this grassfed beef article series is primarily derived from an April 2017 independent report titled ‘Back To Grass: The Market Potential for U.S. Grassfed Beef’” (Bauman, 2021)
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