SFA vs Dietary Cholesterol restriction

[Stavia]

ok, we now understand what the building blocks called fatty acids look like, BUT they don't occur like this in food. They are found joined to a "glycerol" molecule.

The glycerol looks like this. Please note it has three little sticky out thingies that are available to hold hands with something

Glycerin_Skelett_svg.png

It loves to hold hands with three fatty acid chains. Thus we get the word "triglyceride". Tri meaning three.
Remember I said don't worry about the word "acid' yet? now it comes into play. Acid means the fatty acid molecule can give up a hydrogen atom, thus freeing a hand. It can then use this hand to hold onto one of the hands on the glycerol molecule.
Here is a picture of a triglyceride, you should be able to recognise the three fatty acids in this triglyceride. The red one is polyunsaturated. Can you work out what the blue and green ones are?

[Julie G]

Green, MUFA, Blue, SFA? Could be totally wrong..

[MarcR]

I am enjoying the tutorial, Stavia - thank you!

[Stavia]

Green, MUFA, Blue, SFA? Could be totally wrong..

you get the gold star!!!
Will get onto effects of saturated fats after next patient

[Stavia]

I am enjoying the tutorial, Stavia - thank you!

lol thanks. I love teaching actually.

[Stavia]

okies, lets look more closely at saturated fats because now we understand where they fit in having started big picture first.
In the body they are found as triglycerides, made up of a glycerol with three attached chains of fully saturated fatty acids ie no double bonds.
These fatty acids can be between 3 and 36 carbon atoms long. Here again are some names we will recognise:
Butyric acid with 4 carbon atoms (contained in butter)
Lauric acid with 12 carbon atoms (contained in coconut oil, palm kernel oil, and breast milk)
Myristic acid with 14 carbon atoms (contained in cow's milk and dairy products)
Palmitic acid with 16 carbon atoms (contained in palm oil and meat)
Stearic acid with 18 carbon atoms (also contained in meat and cocoa butter)

Now - why are they supposedly so bad for us?
This is very difficult to tease out. It is not as obvious as "eating too much sugar causes diabetes in those who have insulin resistance". Much of our current recommendations are based on association. For instance I have posted a meta-analysis (pooled data from many different trials) showing an association between saturated fat intake and dementia. Other meta-analyses have shown associations between saturated fat intake (and now you all know this is NOT the same as cholesterol intake - it is unsure if cholesterol intake within reason tracks with disease) and CVD (cardiovascular disease). The fact that people tend to confuse the words cholesterol, fat, and saturated fat IMO has added to the confusion.
Is it plausible that increased dietary saturated fat intake does in fact cause CVD? or Dementia?
Well, one mechanism that is immediately obvious is that the dietary saturated fat has to be carried by something, and that is the LDL particle. Remember we discussed how the LDL particle itself is atherogenic (causes atherosclerosis) regardless if it is carrying cholesterol (and will register and can be measured on a normal lipid panel) or carrying triglyerides (and is not able to be measured on a normal lipid panel but needs to be measured with apolipoprotein b or a NMR)? More LDL particles means more atherosclerosis (usually).

Here is an excerpt from a review and we get to the nubbin of it: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2943062/

There exists considerable inter-individual variation in the response to dietary saturated fat. The ability of saturated fats to raise LDL cholesterol is enhanced by increased intake of dietary cholesterol as well as baseline LDL cholesterol concentrations [2•]. Intrinsic differences in the regulation of lipid metabolism may partly explain the heterogeneity of responses to dietary saturated fat. In fact, an association of the apoE4 allele with a greater LDL response to saturated fat has been reported in a number of studies, although this effect is confounded by the relationship of apoE4 to baseline LDL levels

My comment on this is as follows:
1. "There exists considerable inter-individual variation". No shit Sherlock. This IMO has caused considerable confusion cos people can be in two or more camps, each defending their position evangelistically cos it works for them. As my hubby says. Do. Your. Own . Research. ie test yourselves after each diet change.
2. If there is even a breath of suspicion that something is bad for apoe4 and its not cray cray, if I don't need it to be healthy, I'm outa there.

here's another long paper talking about saturated fat and effect on lipids
http://jn.nutrition.org/content/135/9/2075.full


***oops - I forgot to explain a term we use - Lipids are a group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, phospholipids, and others. And now you know what sterols and TGs are. You can work out what a monoglyceride and diglyceride is (two and one fatty acid holding hands with a glyycerol). A phospholipid is a diglyceride and a phosphate group and maybe some choline. Phosphatidylcholine is a phospholipid. It is used to form our cell membranes in a nice double layer like a balloon.

In fact, SFAs are recognized as the single dietary factor that has the greatest negative effect on LDL cholesterol (LDL-C) concentrations

[apod]

I try to keep mine under 7 grams a day and if I pig out, it may go to 10grams max and then I feel bad.

I'm curious, ~how many gram of carbs do you eat (starches, sugars, complex carbs) / how often / how many kcal? It looks like pulling SFA too much lower would substantially raise my carb-intake (which maybe isn't such a bad thing, although I do enjoy the feeling of low-carb / intermittent ketosis and feel like there are benefits there.) On the other hand, it would also lower my PUFA intake, which would definitely be a good thing, imo. Anywhere in the 50-150gram range for carbohydrates has been really comfortable for me for the past couple years or so, eating mostly vegetables with some low-carb fruits / berries and safe starches on top with a good 16hr gap between dinner and breakfast and a 6-7hr gap between breakfast the next meal -- 2200-2500kcal is about what I need (even the occasional 2,800-3,000kcal works great), but I can scoot by for a while under 1900 (bmi is around 23.2, but body fat is ~8 or 9%.)

Looking at today's cronometer after cutting back on fullfat dairy (I tried some nonfat grass-fed filmjölk today -- not bad!) and moving toward the leanest cuts of meat, it looks like olive oil is now my main contributor of SFA, where <15g might be comfortable for me (today didn't have quite enough calories, but clocked in around 11.5g SFA.) Next on the list would be dark chocolate and nuts as major SFA contributors. I think I could be satisfied dialing back to smaller servings and using cocoa powder in place of chocolate.

I'll be curious to try to dial this in and rerun the test in 3-6mo.

[Stavia]

I try to keep mine under 7 grams a day and if I pig out, it may go to 10grams max and then I feel bad.

I'm curious, ~how many gram of carbs do you eat (starches, sugars, legumes?) / how often / how many kcal? It looks like pulling SFA too much lower would substantially raise my carb-intake (which maybe isn't such a bad thing, although I do enjoy the feeling of low-carb / intermittent ketosis and feel like there are benefits there.) On the other hand, it would also lower my PUFA intake, which would definitely be a good thing, imo. Anywhere in the 50-150gram range for carbohydrates has been really comfortable for me for the past couple years or so.

Looking at today's cronometer after cutting back on fullfat dairy (I tried some nonfat grass-fed filmjölk today -- not bad!) and moving toward the leanest cuts of meat, it looks like olive oil is now my main contributor of SFA, where <15g might be comfortable for me (today didn't have quite enough calories, but clocked in around 11.5g SFA.) Next on the list would be dark chocolate and nuts as major SFA contributors. I think I could be satisfied dialing back to smaller servings and using cocoa powder in place of chocolate.

I'll be curious to try to dial this in and rerun the test in 3-6mo.

I'm on about 1200ish calories a day. Gilgamesh says I have a very efficient metabolism. I seem to have stopped losing weight and am at BMI 23.
My carbs are around 80-100 grams=400 -500 calories. Only non starchy veggies and salad and fruit. No legumes, grains, pottaoes. Very occasional sweet potato.
Fats around 400 to 500 calories as well - avocado (quarter), olive oil (1 to 2 T max a day), fatty fish, nuts (10 to 20 grans max a day). Protein is around 300 calories = 60 grams (I weigh 63kg). Protein overwhelmingly fish.

[apod]

I'm on about 1200ish calories a day.

Ah, a low-carb, low-fat, moderate protein diet -- nice! That is one way to avoid driving higher carbs up while avoiding SFA, although I don't think I could comfortably pull that off.

[Stavia]

I'm on about 1200ish calories a day.

Ah, a low-carb, low-fat, moderate protein diet -- nice! That is one way to avoid driving higher carbs up while avoiding SFA, although I don't think I could comfortably pull that off.

I'm a middle of the road girl all the way
But I can only do it cos my maintenance calories are so low. If I were a dynamo like Julie needing 2000 cals to stay reed thin and sexy, I dunno what I'd do....