You might guess that there is some chemical switch in hibernating animals that somehow slows their metabolism and you’d be right, but you’ll probably be shocked when you learn how this mechanism works. You’ll also likely be surprised to learn that this mechanism exists in humans and that there is always a large amount of this enzyme present in obese people.
This enzyme, known as scd1, works in a quite mystifying manner. It takes saturated fat in the body and converts it to unsaturated fat. This in turn impairs mitochondrial function, and slows your metabolism, and allows animals to fatten up for winter.
Also interesting is that there are many studies showing that consuming stearic acid, the main component of beef and dairy fat, speeds up your metabolism.
While there have been human studies as well, the most interesting study was a rodent study where a high fat diet full of stearic acid reduced their total fat percentage by 25%, dramatically lowered dangerous visceral fat, and even increasing lean tissue by 4%! All on the same calories as the other mice.
The short, short version is that within cells, succinate is a signalling molecule for the mitochondria which cause them to both strengthen and create new mitochondria, increasing the energy capacity of the cell. It also increases the production of heat energy by the mitochondria. So as succinate goes up, metabolism goes up. As succinate goes down, metabolism goes down.
Burning fat is a slow process, but it’s the cleanest and healthiest form of energy. It’s also the main fuel source for the body except during intense exercise. It accounts for about 70% of all energy production in the body, and even more when in ketosis. The more you burn fat, the more succinate accrues in the cell, and the higher your metabolism goes over time.
Lineolic acid, from seed oils, burns quickly like carbs do but also has many other problems. It quickly depletes succinate and NAD+, which turns off the Sirt3 antiaging mechanism of your cells and also slows your metabolism.
By contrast, longer chain fatty acids create a surplus of succinate and NAD+ when they are burned. So a long chain like palmitic acid burning will stimulate quite a bit of mitochondrial growth; however, stearic acid is a special case, because it has an odd number of carbons. This means the body much first carboxylate it before it can completely burn it. This will very dramatically slow down the fat burning process.
When not enough energy is being produced due to being caught up burning stearic acid, the succinate builds up quickly and this signals the mitochondria that they need to increase in numbers and functionality. And this speeds up the metabolism of the cell.
Think of it like this: the mitochondria produces succinate at a steady rate, while some forms of fuel burn very slowly so excess succinate is produced that signals that more mitochondria and heat energy must be produced.
At this point you may think this is very complicated and esoteric, perhaps even nonsensical.
But when you take a deep dive, this does make sense. PUFAs like lineolic acid are mobilized more easily so burn off first, and when you have PUFAs and carbs in the blood it generally means you have eaten recently. This also means that heat in the body is abundant, and in nature this probably means it is a warmer time of year.
The winter is when the body needs to create more heat, and as you eat less over a long winter, or fast, you tap more and more into your stored saturated fat supply. So for the body, it makes perfect sense to spend more energy on heat output when you burn saturated fat. And when you burn fat you must have mitochondria in order to be able to burn enough fat to get enough energy, so it also makes sense for the mitochondria to increase.
So not only does saturated fat not cause heart disease, but it is one of the healthiest things you can ingest.
You may be interested to know that you can trigger succinate in other ways, such as fasting, exercise and vibration
So the cliff notes, in case all the mumbo jumbo went in one ear and out the other:
animals go into torpor by triggering an enzyme that desaturates fats because unsaturated fats slow the metabolism while saturated fats speed it up. Seed oils also trigger this enzyme in humans. Lineolic acid from seed oils is especially harmful and stearic acid, which is the predominant fatty acid in beef and dairy, is especially beneficial. They do this by indirectly affecting succinate and NAD+ levels because of how fast they produce energy.
This can also be take as a supplement, brought on through shivering, through exercise or by anything else that makes your fat cells jiggle.
Music courtesy Karl@whitebataudio
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