Saturated Fat is in the Eye of the Beholder; also Ants and Torpor

I wanted to make a quick post to point out a real bias in the literature about how the phrase “saturated fat” is used. Lard is always referred to as saturated fat. Never mind that it’s always less than 50% saturated.

I also wanted to apologize for not getting around to make summary posts of my Obesity Explained videos. Time in the day! But watch the videos.

Temperate Ants, MUFA and Anteaters

I’ve been researching the fat composition of edible insects. I’m not terribly interested in them as a food source for humans, but the research being done gives us a window into the dawn of mammalian torpor.

Many studies have shown that the dietary fat choices of hibernators have a very real affect on their ability to hibernate successfully. (Geiser, 1987) The idea that mammals evolved to get torpid by using the fats found in fall fruits like acorns is appealing but ignores the reality that mammals evolved 40 Million years before flowering plants. In fact, the evidence would suggest that early mammals largely ate insects.

So if you want to know how fat composition effects torpor, you have to start with bugs. There can’t be a better example of a very early mammal who eats insects and hibernates than the echidna, AKA spiny anteater. Echidnas live in temperate Tasmania and, as the name implies, eat ants and termites. They are closely related to platapi, making them the worlds most ancient extant lineage of the mammalian family tree. They lay eggs and the babies lap up milk through Mom’s skin. They never evolved nipples. Ancient mammals.

Luckily for us, someone studied the fat composition of their diet and body fat before and after hibernation. (Falkenstein, 2001) Echidnas eat MUFA rich temperate ants, presumably aided by increased SCD1 expression, to liquify their body fat to something resembling olive oil to become torpid.

They burn off the MUFA over the winter so that by spring their bodyfat resembles that of a self-respecting mammal. In this case I’ve compared it to that of a mangalitsa hog: a famously fatty breed. You can see that the much leaner landrace hog has less MUFA. You can also see that equatorial ants from Kenya have fat more comparable to lean hogs than torpid echidnas. (Ayieko, 2012)

So then, what is saturated?

As you can see there is considerable overlap between the fat composition of edible insect fat and mammal fat. However, the differences in the language discussing the fat compositions are huge.

Consider the phrasing of this paper from Nigeria, discussing an edible termite. (CU, 2012) “The high fat content of the termite was made up mainly of unsaturated fatty acids (60.64%), consisting of 53.07% monounsaturated and 7.57% of polyunsaturated fatty acids.” So a fat that is 40% saturated is accurately called mainly unsaturated since its about bugs.

Now let’s look at a paper TITLED, “Learning and Memory Impairment in Rats Fed a High Saturated Fat Diet”. You can see that the phrase High Saturated Fat is right there in the title. The high saturated fat being referenced is lard and they analyze the lard they are using: 35% saturated, 36% MUFA and 18.8% PUFA!

So the “saturated” lard is much more unsaturated than the “mainly unsaturated” termite oil. Got it?

Lard is frequently and unironically referred to in the nutrition literature as simply saturated fat. This paper is ABOUT fat composition and simply sees lard as saturated. (Putti, 2016) “We showed that the replacement of lard (saturated FA)”. Lard is just simply saturated. End of story.

Termite oil is mostly unsaturated, though. ‘Cause it’s from bugs and bugs are good.

Conclusion

The nutrition industry has clear biases in what they consider saturated fat. Obviously I’m the first one who finds this funny. Except it’s really not funny. It’s hurting science. When you do a research paper about lard you should be honest with yourself and with your readers what its made of.

Also, it’s pretty cool that insects get higher in MUFA as they get further from the equator and this shift is matched by the mammalian hibernators who eat them. Dontchathink?

Most important takeaway: baby echidna’s are VERY cute!

Merry Christmas and Happy Holidays everyone. 2023 is going to be a big year for all things Fire In A Bottle! If you haven’t yet, check out the new Obesity Explained video series on FIAB YouTube!

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CU, I., CO, U., & LA, N. (2012). Chemical Analysis of an Edible African Termite, Macrotermes nigeriensis; a Potential Antidote to Food Security Problem. In Biochemistry & Analytical Biochemistry (Vol. 01, Issue 01). OMICS Publishing Group. https://doi.org/10.4172/2161-1009.1000105

Falkenstein, F., Körtner, G., Watson, K., & Geiser, F. (2001). Dietary fats and body lipid composition in relation to hibernation in free-ranging echidnas. In Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology (Vol. 171, Issue 3, pp. 189–194). Springer Science and Business Media LLC. https://doi.org/10.1007/s003600000157

Geiser F, Kenagy GJ. Polyunsaturated lipid diet lengthens torpor and reduces body temperature in a hibernator. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. Published online May 1, 1987:R897-R901. doi:10.1152/ajpregu.1987.252.5.r897

M.A. Ayieko, J.N. Kinyuru, M.F. Ndong’a and, G.M. Kenji. (2012). Nutritional Value and Consumption of Black Ants (Carebara vidua Smith) from the Lake Victoria Region in Kenya. Advance Journal of Food Science and Technology 4(1): 39-45, 2012.

Putti, R., Migliaccio, V., Sica, R., & Lionetti, L. (2016). Skeletal Muscle Mitochondrial Bioenergetics and Morphology in High Fat Diet Induced Obesity and Insulin Resistance: Focus on Dietary Fat Source. In Frontiers in Physiology (Vol. 6). Frontiers Media SA. https://doi.org/10.3389/fphys.2015.00426