Is it me or is there so much conflicting info floating around out there on fats recently, right? What we really want to know is, which ones are actually good for us, which ones do I need to avoid, and how do I know the difference? So I took it upon myself to get up to speed on the latest research and after many hours of getting it all sorted out - here’s what you need to know!
Below I have listed each type of fat: saturated, monounsaturated and polyunsaturated. Under each I explain what they are, why you need them, the best dietary sources, and I comment on a few points about each that seem to have the most confusion.
Saturated Fats:
What are they:
On saturated fats all potential bonding sites on the carbon atoms of the fatty acid chain are occupied by hydrogen, therefore “saturated.” They’re temperature stable (resistant to oxidative damage when exposed to heat), which makes them a good choice for cooking.
Why you need them:
They contribute to critical metabolic functions and protect against oxidative damage. They also enhance the immune system and play a vital role in bone health. Our cell membranes are composed partially of saturated fat.
What may need clarification:
1. We’ve been told for years to avoid saturated fats like the plague, so why are they ok now? Here’s the deal. The idea that saturated fats should be avoided at all costs can be traced back to Ancel Keys, PH.D. and the Seven Countries Study he conducted from 1958 - 1970. Keys had set out to prove the diet-heart hypothesis: that high saturated fat consumption causes high cholesterol in the blood which causes heart disease. However, when publishing his research he only analyzed the information from 7 counties, although he had data from 22. He excluded the countries that did not fit his hypothesis. This flawed research is what years of dietary fat guidelines have been based on.
2. Studies have shown that saturated fats raise protective HDL cholesterol. They also raise LDL, however, there are 2 types of LDL cholesterol; small, dense LDL and large, “fluffy” LDL. Small, dense LDL does contribute to the build up of plaque in the arteries, but saturated fat increases the large, fluffy benign LDL.
3. Finally, when saturated fats are consumed in the presence of excessive carbohydrates unhealthy fat storage will increase…however, when consumed on a low carb diet they are a clean burning fuel.
Best Sources: Grass fed meats, Grass fed butter, Coconut oil, tallow, lard
Monounsaturated Fats:
What are they:
These fats contain a single double bond on the fatty acid chain. They’re less temperature stable than saturated fats so should not be used for high temperature cooking.
Why you need them:
They’re good for cardiovascular and immune function, and to protect against heart disease.
What may need clarification:
Not much:) Monounsaturated fats are widely accepted to be healthy and are known for being a staple of the “Mediterranean" diet.
Best Sources: Extra Virgin Olive Oil, Olives, Avocados, Macadamia nuts
Polyunsaturated Fats:
What are they:
These fats contain more than one double bond in their fatty acid chain. They remain in liquid form at room temperature and below. They are easily susceptible to damage from light and heat and are definitely not suitable for cooking. They are often referred to as PUFAS, an abbreviation for Polyunsaturated Fatty Acids.
Polyunsaturated fats are broken into 2 categories of Essential Fatty Acids (EFAs):
Omega-6 and Omega-3. They are labeled essential because your body cannot manufacture them internally; they must be obtained from your diet. Omega-6 PUFAS are named for the hydrogen double bond at the 6th carbon in the fatty acid chain, and likewise omega-3 PUFAS are named for the hydrogen double bond at the 3rd carbon in the fatty acid chain.
Omega-6:
Why you need them:
You need them for proper brain function; they also stimulate skin and hair growth, maintain bone health and help regulate metabolism
Best Sources: Flax, hemp, chia, pumpkin & sunflower seeds, pine nuts, pistachios
Omega 3:
Why you need them:
You need them for proper brain, skin, cardiovascular and immune function.
Best Sources: Oily cold water fish (wild, not farmed), pasture raised eggs, pasture raised animal meats, leafy greens
What may need clarification:
1. Omega-6/Omega 3 Ratio:
An ideal ratio is 1:1, but 4:1 is an adequate healthy ratio to aim for in your diet. A typical American has a ratio of 20:1 or higher! This is because the SAD (Standard American Diet) obtains the majority of it’s PUFAs from industrial oils, and those oils are included in many processed foods and snacks. This includes canola, safflower, soy, corn, and peanut oil. What makes them especially unhealthy? These refined oils are processed with a petroleum solvent to extract the oil, heated some more, treated with more chemicals to improve color, and deodorized to remove the smell from all these chemical processes. They go rancid and oxidize easily, causing inflammation when you ingest them. This is why even “organic” vegetable oils are not a good choice…they may not be genetically engineered or contaminated with glyphosate but they still go through this industrial process.
2. Omega 3s: Plant Based vs Animal Based Sources
There is a major difference in the omega-3 that you get from plant vs animal sources. Marine based omega-3 primarily contains DHA (docosahexaenoic acid) and EPA(eicosapentaenoic acid), while plant based omega-3 contain ALA(alphalinolenic acid). DHA and EPA are crucial for health and particularly brain health. ALA is a precursor to EPA and DHA, but an enzyme is needed to convert it and typically your body can only convert a very small amount. This is why plant based omega-3s can’t be substituted for animal based omega-3s.
I hope this breakdown resolves some of the confusion about the different types of fats. If you’re still a little bit stuck on the idea that saturated fats are good for you, think about this for a moment. The general state of health for most Americans has been declining for the past 40+ years. Many of the foods that the “experts” have been telling us to eat in place of saturated fat and cholesterol contain unstable polyunsaturated fats from seed oils…but where has that gotten us? (and yes, sugar plays a huge role too but that's a whole separate blog topic...) If we as a country are unhealthier than ever before, it makes logical sense to me that we’ve been doing something wrong and it’s time to change our way of thinking…and eating!
