Alright so I'm trying to get my facts straights on the different fats and how each one effects your cholesterol levels. And I figured here would be the best place to ask.
Saturated Fat - Raises HDL and LDL (but the fluffy LDL)
Monounsaturated Fat - Raises HDL and Lowers HDL
Carbs lower both.
How does Polyunsaturated fats effect us?
Now I've heard Canola oil is bad for you, yet isn't it high in Monounsaturated fats?
asked byJosh_25 (0)
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on May 06, 2013
at 04:37 PM
Check out these guides for great, easy to digest info:
What Are PUFAs?
Chemically speaking, polyunsaturated fats have more than one (hence the ???poly???) double bond in their carbon chain. They???re further determined by the position of these double bonds in relation to the end of the molecule. For example, omega-3s sport a double bond three ???links??? down from the ???methyl??? end of the molecule.
These double-bonded carbon links are in essence missing their hydrogen atoms. (As you recall, if all the links have their hydrogen, you???re looking at a fully saturated fat.) Because they???ve got multiple ???incomplete??? double bonds to their name, polyunsaturated fats are, as a class, chemically unstable and prone to oxidation.
What Do They Do?
PUFAs can be a real Jekyll and Hyde. On the one hand, PUFAs include the essential fatty acids, including our favorite omega-3s. But when oxidation comes into play, we???re looking at a whole different animal. Heating in particular sets a bad course in motion, but simply exposure to air, light and even moisture can incite the process. We???re now looking at lipid peroxides, which initiate a free radical free-for-all. The free radicals make their way through the body pillaging at every turn. Their damage takes a toll on everything from cell membranes, to DNA/RNA strands, to blood vessels (which can then lead to plaque accumulation). The harm adds up over time in the organs and systems of the body and can cause significant impact, including premature aging and skin disease, liver damage, immune dysfunction, and even cancer.
For Canola oil, you can check out this great article:
Canola was a hybrid derived from rapeseed to reduce the high erucic acid content of traditional rapeseed oil, which had a bitter taste and toxic effects from the acid. Canola oil is also called LEAR (Low Erucic Acid Rapeseed). Like most cash crops, the largest share of the market is by far GMO-based, and one corporate GMO giant, Monsanto, has been accused more than once of the release of unapproved GMO seed varieties. Despite all the genetic engineering, somehow canola remains one of the most heavily pesticide-treated crops.
Once harvested and graded, seeds are heated to facilitate oil extraction. Most canola oil is chemically extracted using the harsh petroleum-derived solvent hexane. Even when expeller pressing is used, a process common to organic brands, the massive force of industrial presses still produces heat. True ???cold-pressed??? canola oil (extracted with millstones) does exist but can be hard to find and is more expensive.
Following extraction, canola oil must be de-gummed to remove unappealing solids that settle during storage. The process involves heat and sometimes the addition of acids. Next stop, the oil is then bleached and separated. Finally, the oil (known for its stench) must be deodorized through heating methods that use temperatures as high as 500 Fahrenheit.
(Frankly, the whole process is rather unappetizing if you ask me. Deodorized food? Seriously.) This brings us back to the omega-3 issue. Polyunsaturated fats aren???t the most stable fats out there. In fact, they???re pretty sensitive to heat and will turn rancid quickly. Obviously, canola oil undergoes a good deal of heating and heat-related degeneration in its processing. Needless to say, this is no good. Whatever omega-3 benefit there might have been is gone ??? like keys in lava, as one of the old Jack Handey quotes put it. What???s more is, you end up with a small but damaging amount of trans fat in your ???heart healthy??? oil. How???s that for irony?
My thinking is this: why bother with something so processed and unhealthy when there are umpteen other, better options out there? Olive oil, coconut, palm oil, lard and ghee are suitable for most cooking applications. And for salads and other ???no heat??? dishes, you have dozens of tasty (non-deodorized) choices, including avocado and nut oils. As for canola, who needs it?
on May 06, 2013
at 11:48 PM
Some general things to add. Carbs, mainly fructose, can raise blood triglyceride levels. High triglycerides and Low HDL are very important biomarkers of cardiovascular risk. And very generally: PUFA's will effect inflammation levels in your body. Omega-6 fats are inflammatory, and Omega-3 fats are anti-inflammatory. The ratio between the two is extremely important, and should probably be as close to 1:1 as possible. Many Americans are likely closer to 15:1.