Dr. Michael Eades on Seed Oils: Qs and hopefully As

tl;dr: Dr. Eades is one of the savviest people I know in this space. I'm honored he's taking my hypothesis seriously enough to write about it.

Dr. Eades is one of the more knowledgeable people in the diet and obesity space. Aside from starting his training as an engineer, he independently invented the idea of the Paleo diet, had a successful medical career, and wrote one of the best-selling diet books of all time.

Protein Power.

He’s also got an excellent newsletter/blog now called The Arrow. I’ve come up in it in two recent installments, #165 and #199.

Arrow #165

The relevant section from 165 is “Obesity, Seed Oils, and Sugar”, and starts:

“This morning I received the latest Substack post from my friend Tucker Goodrich titled Response to Gary Taubes on Omega-6 Fats (Seed Oils) and Obesity.

“The post, which is well worth a read, contrasts Gary’s take on what’s driving the obesity and diabetes epidemics (sugar) to Tucker’s (seed oils).

“Gary’s contention—and I’ve discussed this with him many, many times—is that…”

I’m not going to copy the whole thing. Dr. Eades has a couple of comments/questions on it though, and I thought I’d address those here.

“But based on the info in Tucker’s post from this morning, I did learn that seed oils have been around in the US a lot longer than I thought they had. And up until the late 1970s, obesity held steady.

“Same with sugar. Sugar has been around forever and obesity rates held steady till the late 1970s.

“So, maybe there is a threshold effect for both of them. And those of us in the US hit it starting in the late 1970s.”

Clearly it is a key question: when did obesity go from being a rarity to being common?

This woman was so uniquely fat in 1864 she made a nice living from appearing in the circus.

In general it is true that there is not really any obesity data prior to the 1960 (so I’ve been told), but I’m aware of a few studies attempting to interpolate that gap in the data with older data.

“Changes in the Distribution of Body Mass Index of White US Men, 1890–2000”

“While behavioural explanations primarily focus on the increase in mean or median BMI, our data also show that the long-term shift in location of the distribution of BMI only accounts for 75% of the increase in obesity prevalence. The remainder is mostly attributable to the fact that the higher quantiles of the BMI distribution increased faster than the lower quantiles. While this pattern has been observed in recent surveys (cf. Friedman 2003), the present study confirms that this trend can be traced back as early as the late 19th century.” (Helmchen, 2004)

“The Trend of Mean BMI Values of Us Adults, Birth Cohorts 1882–1986 Indicates That the Obesity Epidemic Began Earlier Than Hitherto Thought.”

“…The birth-cohort approach also enables us to calculate the annual rate of change of BMI values, whereas the period-effect approach does not.”

“…The rate of change in BMI values was anything but continuous. Rather, the general upward trend was punctuated by upsurges, particularly after each of the two World Wars. The birth cohorts of the 1920s experienced a rapid increase in BMI values.” (Komlos, 2010)

And, perhaps most telling (via Speakman, 2023):

“Decreasing Human Body Temperature in the United States Since the Industrial Revolution”

“In this study, we analyzed 677,423 human body temperature measurements from three different cohort populations spanning 157 years of measurement and 197 birth years. We found that men born in the early 19th century had temperatures 0.59 ̊C higher than men today, with a monotonic decrease of 0.03 ̊C per birth decade. Temperature has also decreased in women by 0.32 ̊C since the 1890s with a similar rate of decline ( 0.029 ̊C per birth decade).” (Protsiv, 2020)

Unfortunately I don’t think this data alone helps us reconcile sugar vs. seed oils as causative of obesity, but it does let us put it in the correct context.

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Dr. Eades goes on to discuss a remarkable look at what happens to us when we have excess Ω-6 PUFA in our adipose tissue.

(Khatua, 2021)

A colleague’s daughter died last spring at 37 of necrotizing fasciitis, and I can’t help but wonder if this is related to the increase in seed oils in our diet, as a related condition in infants (necrotizing enterocolitis) is associated with a high PUFA intake (Alshaikh, 2022).

Arrow #199

“I’m sure my friend Tucker Goodrich, who I suspect is all over this, will inundate me with papers when he reads this.”

Too funny.