More than you wanted to know about a little-understood but important aspect of diet and health, explained in a nontechnical manner, with oversimplifications abound.
Your cells need some kind of fuel to function. this fuel can only come (ultimately) from the outside world as food. AKA "diet". your blood carries the fuel to the cells so they can do their work. on most diets, the main fuel for cells is glucose, which the body derives from sugar or carbohydrates (which are basically sugar + some complexity).
on other diets, the main fuel for cells is fat. on these diets, fat/lipid particles are carried on little blood ferries called lipoproteins (the final "L" in LDL and HDL). LDL carries lipids _to_ your cells so they can use it, HDL carries unused lipids _away_ from your cells (to the liver) so they can be disposed of. (on both very high carb and very low carb diets, your cells will still use some amount of both glucose and fat for energy, but the ratio will change dramatically).
Naturally, if you have a lot of these ferries in your blood (because you are using fat as cell-fuel), your LDL and HDL counts ("total cholesterol") will be high on basic blood tests.
LDL - the ferries that carry fats to your cells to burn - come in two varieties:
- small + dense
- large + fluffy
both carry fuel to your cells, but the small/dense ones have an unfortunate side-effect of slamming into artery walls, penetrating them, and accidentally depositing their lipids there. This is the "plaque" of cardiovascular disease fame. The large, fluffy particles do not penetrate the arterial walls as readily - they bounce off and keep going on to their destinations. their effect on arterial plaque is not zero, but far less impactful than small, dense particles.
In either case, the HDL particles are always good: they remove excess lipids from the body. this is why HDL is "the good cholesterol". There are advanced blood tests available which measure particle size (so, like, an _acutally useful_ test), but odds are your doctor will refuse to order this test. Strange!
We didn't mention Triglycerides yet. Suffice it to say that more triglycerides = smaller, denser LDL particles = more arterial wall penetration = more cardiovascular risk. To finish off our triglycerides sidebar, the dietary patterns that increase triglycerides (bad!) are: excess calories from carbohydrates, added sugars and refined carbohydrates, low fiber intake, low omega-3 intake (especially in combination with excess seed oil intake), high trans fats consumption (more on trans fat in a moment).
Back to finish up cholesterol: this is why a diet that is high in _good fats_ (again, more in a moment) will increase "total cholesterol" - you have more fat boats fueling your cells - but doesn't indicate greater cardiovascular risk: because the large, fluffy particles are not damaging your arteries and the large number of HDL particles are protective!
Furthermore, if you reconsider the sidebar on triglycerides you'll notice that avoiding refined carbohydrates and sugars has the added effect of lowering triglycerides, which keeps the LDL particles even healthier. You'll often see the simple recommendation to keep the HDL/Triglycerides ratio high. this is why. HDL good, triglycerides bad.
We didn't even get into insulin sensitivity - one of the most important factors in metabolic health... another time.
A last word on dietary fat types: Not all fats are created equally. You can look into monounsaturated and polyunsaturated on your own, but I want to mention two others here: Trans fat and Saturated fat.
Trans fats mostly come from _artificial sources_, like processed vegetable or seed oils. most often found in ultra-processed, packaged foods. yuck. trans fat **lowers HDL, increases inflammation and increases proportion of small, dense LDL particles**. These are all the bad things we discussed above.
Saturated fat is mainly found in meat, dairy and coconut oil. It **increases LDL particle size and raises HDL**. These are the good things we discussed above.
So, yes, while someone's _total cholesterol_ may go up when eating saturated fats, it doesn't necessarily mean their cardiovascular risk has increased.
Now that you understand how cholesterol works, compare moderate saturated fat intake to eating a diet full of refined carbohydrates, sugars, processed vegetable/seed oils, and all the other items we explained above...
Ok really now, the **last** last word: the "cholesterol" you see on a food label has less impact on blood cholesterol than you thought. the details are too squirrely to go into here, but the takeway is: the fat content discussed above is the lion's share of the impact, with the number you see next to "cholesterol" on your food label having a negligible effect.
#diet #paleo #keto #health #healthstr #foodstr #carnivore #cholesterol
