Fat - Part 2
Dietary Fat 101
While I’m happy to bid farewell to those low-fat days of yore, there’s still an important type of fat that’s being at least moderately vilified – saturated fat.
Let’s look at all of the different types of fat so you can understand the chemistry of fat, and then we can talk about healthy vs inflammatory fat.
Also, fatty food is usually discussed as being one type of fat. Like butter is saturated fat and olive oil is monounsaturated. But food is rarely as simple and black and white as that.
Butter is about 60% saturated fat and contains a decent amount of monounsaturated fat. The % of saturated fat lowers and unsaturated fat increases when a cow is fed its proper diet (grass). Olive oil contains about 14% saturated fat.
…like with carbs, the conversation about fat requires nuance and flexibility.
Saturated Fat
Saturated fats are solid at room temperature and they’re also pretty darn stable. This is key. Saturated fats are super mega stable and take longer to go rancid compared to unsaturated fats.
Saturated fats are commonly found in animal-based foods, as well as in coconut oil and palm oil.
As with all foods that come from an animal, the quality of the fat depends on what the animal eats. Organic butter has a deeper color and contains a different blend of nutrients (including anti-inflammatory omega-3 fatty acids) than conventional butter because the cows that produce the milk for organic butter eat much more grass than grains.
Organic butter also contains much higher levels of conjugated linoleic acid (CLA) and butyric acid, which are both notable fats that may have anticancer potential.
Don’t be fooled by the media-driven nonsense about saturated fats. You need some in your diet every day. They’re essential.
But…what about heart health? Don’t I need to reduce saturated fats to lower my cholesterol and protect my heart?
While this idea has been promoted as fact for decades (since about the 1950s), the research on this is scarce and inconclusive.
The original recommendation was based on an observational study and out of that came the diet-heart hypothesis. This was the idea that saturated fat lodges in the arteries…even though that’s physiologically impossible.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6053258/
While this remained an unproven hypothesis, it’s usually stated as fact and has been used to sell margarine, low-fat foods, and other highly refined oil products as replacements for saturated fat.
There were some studies done in the 1980s that did show that saturated fat was a problem but, they also included nasty trans-fat in the mix (which IS a problem), so one can’t deduce that saturated fat alone is an issue from those studies.
Then, in 2010, a huge cohort study was released that found the opposite – saturated fats aren’t connected to heart disease. BUT! Low fat foods are! Oops.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2824152/
Many other studies in the last few years have echoed these results:
https://www.healthline.com/nutrition/5-studies-on-saturated-fat
The “saturated fat is bad” narrative is so strong that it’s almost impossible to find any information about what saturated fat does in the body! This is a natural fat, so it must have some uses. We know that butyric acid, which is found in grass-fed beef and butter, has many anti-cancer properties…but must be many other good points, since these natural fats have always been in the diets of humans.
Here’s something cool that we know now:
Your brain is 60% fat and saturated fat plays an important role in making memories. This is new research but points to a need to keep healthy, unprocessed saturated fat in the diet. https://www.sciencedaily.com/releases/2021/06/210628123017.htm
I think over the next few years/decades, now that fat is fashionable, we’ll begin to see more benefits to saturated fat emerge.
A short chemistry lesson before we move on:
Chemically, saturated fat is quite straight, allowing the fatty acids to stack neatly, making it a more solid fat. But, unsaturated fats bend, making them liquid at room temperature.
Here’s a visual:
The “saturation” of a fat refers to hydrogen atoms. Saturated fat is fully saturated with hydrogen atoms, making it a straight and stable fat.
Missing hydrogen atoms create two things: they cause the fatty acid structure to bend, bending more with each missing hydrogen atom. And, these are weak spots in the structure, and this allows for faster rancidity.
In a nutshell, this means that saturated fat has a long shelf-life and polyunsaturated fats (with many missing hydrogen atoms) are very unstable and can go rancid quickly.
The bending of the fatty acid also keeps it from solidifying. Monounsaturated fats have a small bend and are liquid at room temperature but solidify in the fridge.
Polyunsaturated fats, like omega 3 fatty acids, have a deep “C” curve, which keeps the oil liquid even at freezing temperatures. It’s believed this is one of the reasons that cold-water fish are so high in omega-3 fatty acids (they’re creating their own antifreeze :).
Trans-fat are very unique fatty acids. They start their life as “c” shaped polyunsaturated fats, but food manufacturers don’t like that they’ll go rancid so quickly, so they force hydrogen atoms into their chemical structure. This forces them to straighten out…but doesn’t create a nice, normal saturated fat. Instead, this artificially created straightness is very VERY rigid and can cause damage to our tissues when we ingest it. This is just one of the reasons to stay FAR FAR away from trans-fat!
Now that you can picture their structure, let’s look at unsaturated fats :)
Unsaturated Fats
Monounsaturated fats are missing just one hydrogen atom. They’re liquid at room temperature but solidify in the fridge.
Foods high in monounsaturated fats are olive oil, avocados, and many nuts. Unprocessed monounsaturated oils, like cold-pressed extra virgin olive oil, are full of antioxidants and are wonderfully healthy. But, highly processed oils like canola oil (also high in monounsaturated fats) are best avoided.
Since polyunsaturated fats are missing more than one hydrogen atom, so they’re always liquid, even at colder temperatures. They can also spoil a lot faster than other types of fats. The food industry has solved this problem by refining the heck out of polyunsaturated corn, soy, and other vegetable oils. Highly processed oils can stay fresh for a long time but are highly inflammatory to your body.
All unsaturated oils can go rancid easily because the unsaturated spots on the fatty acid chains are weak points that can be “attacked” by oxygen. A bitter taste is a sign of rancidity. Storing unsaturated oil in a dark glass bottle at cool temperatures can lengthen its shelf life.
Omega-3 and omega-6 are the most famous polyunsaturated fats because they’re essential, and play vital roles in your immune system.
Omega-3 fatty acids (O3):
They’re needed for your body to make the anti-inflammatory prostaglandin PGE3. The body uses inflammation for healing, and it needs PGE3 to clean up that inflammation. Without enough omega-3s in your diet, you can have inflammatory issues, like low-grade chronic inflammation.
Omega-6 fatty acids (O6):
They’ve been given a bad name over the last twenty years. They’re necessary for making prostaglandin E1 (PGE1) and prostaglandin E2 (PGE2).
PGE1 is a forgotten but important anti-inflammatory prostaglandin, and PGE2 is pro-inflammatory and necessary, so the immune system can trigger inflammation for healing.
The key here is balance. You need the right amount of these fats for your immune system to work correctly. But for decades, food manufacturers have been using highly refined, pro-inflammatory omega-6 oils (like corn and soy oils) to replace saturated fat in their foods. This practice makes the Nutrition Facts label on food products fall in line with the warning to stay away from saturated fat, but it’s also skewed the average O6-to-O3 ratio.
In 1900, people had about two times the O6 in their diets as they had O3. On average, people today consume about twelve times as much O6 as O3! No wonder inflammation is running rampant right now!
And yes, the food manufacturer’s “solution” to the “saturated fat is bad” narrative has caused a heck of a lot more inflammation than saturated fat would have. Geez!
Okay, you’ve made it through today’s chemistry lesson :). Now that you know the difference between the chemical structures of fat, let’s look at what makes a healthy fat.
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