I spent today looking through the "What We Eat in America" tables produced by USDA (which are taken from food diary data from NHANES), and the average omega balance (= ω-3/(ω-3+ω-6)) has held steady at about 10% for both adult men and women from 2001-2019.
I thought it would be getting worse over time (since soybean oil consumption seems …
I spent today looking through the "What We Eat in America" tables produced by USDA (which are taken from food diary data from NHANES), and the average omega balance (= ω-3/(ω-3+ω-6)) has held steady at about 10% for both adult men and women from 2001-2019.
I thought it would be getting worse over time (since soybean oil consumption seems to be continuing to increase). But if Hulbert is right, a steady 10% seems to be low enough to do a lot of damage over time.
Another explanation could be that people are systematically under-reporting the high-ω-6 foods in their diaries (and these have been getting worse over time).
Interesting! Yea many potential issues with epidemiology. I've been thinking about that with "PUFAcation" in general, not just the balance.
If there is indeed a threshold, let's say 3% LA from kcals, then you could have various weird artifacts in population-wide statistics.
E.g.you could have a population where everybody is at 2.9% and you see no issues. You increase total population wide consumption a little bit, and suddenly you see tons of issues.
On the other hand, maybe 75% of the population are at 10% and 25% are at 2%. If the 75% increase their consumption, not much more might happen. You might conclude that LA is not a culprit, because it went up but problems did not.
Add that the threshold is probably somewhat different between individuals, that a lot of the damage is done cumulatively over time, and so on, and it's just a really, really rough guide.
I think epidemiology is better at ruling out certain things.
E.g. Asians eating 85%+ rice diets for millennia and being healthy/skinny kind of disproves that carbs per se are always the bad guy. I mean, either not in everyone (are some more adapted to starch?) or it's just sugar/fructose, not glucose (the Lustig position), or maybe something else happened *wink nudge* since that made us not tolerate carbs any more..
Similarly, if the obesity epidemic started in 1910 but seed oils were only invented in 1960, I'd be hard pressed (ha, seed oil pun!) to believe they caused it.
There is more detailed data about the distributions of PUFA intake on a different set of tables at that website, but I’m not going to dig into them right now.
I spent today looking through the "What We Eat in America" tables produced by USDA (which are taken from food diary data from NHANES), and the average omega balance (= ω-3/(ω-3+ω-6)) has held steady at about 10% for both adult men and women from 2001-2019.
I thought it would be getting worse over time (since soybean oil consumption seems to be continuing to increase). But if Hulbert is right, a steady 10% seems to be low enough to do a lot of damage over time.
Another explanation could be that people are systematically under-reporting the high-ω-6 foods in their diaries (and these have been getting worse over time).
Source:
https://www.ars.usda.gov/northeast-area/beltsville-md-bhnrc/beltsville-human-nutrition-research-center/food-surveys-research-group/docs/wweia-data-tables/
Steps:
• Grab Table 1 from each year
• Define omega6 = "PFA 18:2" + "PFA 20:4" (Linoleic + Arachidonic; but basically this is all Linoleic)
• Define omega3 = "PFA 18:3" + "PFA 18:4" + "PFA 20:5" + "PFA 22:5" + "PFA 22:6" (ALA + SDA + EPA + DPA + DHA)
• Compute omega balance = omega3/(omega3+omega6)
Interesting! Yea many potential issues with epidemiology. I've been thinking about that with "PUFAcation" in general, not just the balance.
If there is indeed a threshold, let's say 3% LA from kcals, then you could have various weird artifacts in population-wide statistics.
E.g.you could have a population where everybody is at 2.9% and you see no issues. You increase total population wide consumption a little bit, and suddenly you see tons of issues.
On the other hand, maybe 75% of the population are at 10% and 25% are at 2%. If the 75% increase their consumption, not much more might happen. You might conclude that LA is not a culprit, because it went up but problems did not.
Add that the threshold is probably somewhat different between individuals, that a lot of the damage is done cumulatively over time, and so on, and it's just a really, really rough guide.
I think epidemiology is better at ruling out certain things.
E.g. Asians eating 85%+ rice diets for millennia and being healthy/skinny kind of disproves that carbs per se are always the bad guy. I mean, either not in everyone (are some more adapted to starch?) or it's just sugar/fructose, not glucose (the Lustig position), or maybe something else happened *wink nudge* since that made us not tolerate carbs any more..
Similarly, if the obesity epidemic started in 1910 but seed oils were only invented in 1960, I'd be hard pressed (ha, seed oil pun!) to believe they caused it.
There is more detailed data about the distributions of PUFA intake on a different set of tables at that website, but I’m not going to dig into them right now.
You make some valid points!