The FastDay Forum

Last week, I had my bloods tested & The results that came back were not good.my LDL (bad cholesterol) jumped from 4.5 to 6.9 mmol/L. some tests i found on the internet, have shown that this can happen but the jury is still out as to whether fasting improves or affects negatively your cholesterol.
Interestingly though, I sat in front of my doctor to discuss these results and she had her blood results today and her cholesterol has also jumped up!
I have a repeat blood test in 2 months, so time will tell if IF works for me!

[Tracieknits]

I haven't heard of this, but perhaps the clever people in the Nerdy forum below will be able to help you out. Have you had a glance down there yet?

[carorees]

In order to burn the fat it has to be released from the fat cells and circulate in the blood. As we know, many overweight people are not able to switch into fat burning easily but once having done a few fasts this becomes easier. So, high cholesterol is a consequence of fasting but it is not necessarily a bad thing. What were your HDL levels? The ratio of HDL:LDL is more important than actual values. How long had you been fasting before the blood was taken? I recently saw a paper that said there was not much difference in cholesterol readings between bloods taken after overnight fasting and non-fasting but I would not be surprised if that only applies to people who are not able to switch into fat burning easily.

The improvements in glucose metabolism suggests that fasting is beneficial.

Next time schedule your bloods to be taken after a shorter fast and having had carbohydrates with your last meal...i.e try to be like all the other patients who are having cholesterol tests!

Back from walking the dog!
Hi carorees,
Thanks to you and (tracieknits plus seperate congrats to your successful week) for replying.
In answer, the local gp's Focus is on LDL figures but i guess that the HDL's were within acceptable range.
My GP was the one who introduced me to the whole thing and is taking a two day straight fast each week. she i guess has a healthy BMI so won't be burning as much fat as me!!
I think you could also be right Carorees, as last Tuesday's blood test would have followed a Monday fast and been far from any previous bloods I have had tested, but in the meantime, I think I still need to keep a watchful eye on those pesky LDL's

[carorees]

I think you have your answer then. The "true" figure (that is the one that should be used to determine cardiovascular risk) will be the one when you haven't had a long fast beforehand.

Reading thru my 2 default sources, wikipedia and marks daily apple, I don't understand why one's cholesterol ratio should rise after fasting. I don't see how or why HDL or LDL levels should be affected by fasting when the functions of cholesterol do not appear to be linked to fat burning/beta oxidation? Am I missing a very obvious answer? Can anyone shed any further light?

Also, although I haven't gone looking for research papers, there's a lot of online comment that high cholesterol readings on their own aren't necessarliy a useful sign of impending heart problems. Anyone disagree?

Lastly going slightly off topic, the subject of tryglyceride (tgs) readings in a blood test. Tgs are the stored form of free fatty acids which we use as an energy source. The longer we fast our glycogen levels diminish and we become more reliant on mobilizing tgs as we need to convert the free fatty acids into ATP and ketones for muscular and brain energy. So, surely raised tgs levels during and post fasting are a good thing but then again my understanding is they are also bad as they contribute to atherosclerosis and then heart problems etc. Again, any savants out there who can enlighten me?

Hopefully the answers to my questions can be found in the scene from a monty python film..

[carorees]

Reading thru my 2 default sources, wikipedia and marks daily apple, I don't understand why one's cholesterol ratio should rise after fasting. I don't see how or why HDL or LDL levels should be affected by fasting when the functions of cholesterol do not appear to be linked to fat burning/beta oxidation? Am I missing a very obvious answer? Can anyone shed any further light?

See this: http://www.hcplive.com/publications/int ... -Hour-Fast

Also, although I haven't gone looking for research papers, there's a lot of online comment that high cholesterol readings on their own aren't necessarliy a useful sign of impending heart problems. Anyone disagree?

A one off reading is not enough to make a estimation of risk. Also few docs seem aware that the ratio of HDL to total cholesterol is the most important predictor.

Lastly going slightly off topic, the subject of tryglyceride (tgs) readings in a blood test. Tgs are the stored form of free fatty acids which we use as an energy source. The longer we fast our glycogen levels diminish and we become more reliant on mobilizing tgs as we need to convert the free fatty acids into ATP and ketones for muscular and brain energy. So, surely raised tgs levels during and post fasting are a good thing but then again my understanding is they are also bad as they contribute to atherosclerosis and then heart problems etc. Again, any savants out there who can enlighten me?

You are right about raised free fatty acids/tgs being good in that it shows fat is being used. There have been some indications that a high fat high protein diet results in prolonged high tgs which can cause problems with the cardiovascular system. This is why intermittent fasting is good...it allows circulating fat levels to fall.

If you remember from Dr M's book, he mentioned the concept of hormesis (that which doesn't kill is makes us stronger). Fasting is a form of hormesis and the stress it causes strengthens us but if done too enthusiastically it toss from being beneficial to harmful (like red wine, chocolate, cold exposure etc). Our problem is that we don't know where the benefits turn to harms.

Heart risk graphs have the ratio Total/HDL cholesterol on the x-axis, from memory 3.0 or 4 is the lowest value to feature.

Free fatty acids go up when using fat from reserves, not sure about triglycerides. A quick look suggests that triglycerides are reduced during weight loss interventions.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3564212/ shows triglycerides are the lowest on high fat / higher protein / low carb.

Low fat gives the worst TGs.

[carorees]

As always, more studies are needed! The one that I saw was looking at long term diet in rats.

That HCP link said "Triglycerides were 134.2, fell 52.4, rose 11.2 (p = 1.3x10-4)" so lower during fasting. Don't appear to rise with fat burning at all AFAICS.

[carorees]

What do you make of this report?
www.uab.edu/news/latest/item/2182-high- ... art-attack

What do you make of this report?
http://www.uab.edu/news/latest/item/218 ... art-attack

Rats

Doesn't consider the reduced risk of heart attack in a low carb diet through improved lipid profile. May indicate increased severity of consequences but I don't know how/if a rat heart in vitro maps to a living human.

Caroline, many thanks for your reply. Re my first qu on why chol. rises with fasting, I still don't see a clear answer from your link. Dr Horne stated that there was an indication that the flow of chol in and out of the liver stopped "so that you would have it for energy." That sounds to me like he doesn't know why and secondly I still can't find any reference anywhere stating that chol can be used as an energy source.
Re the 2nd qu, googling is high chol bad for you brings back a ton of info, with Gary taubes and his views featuring prominently.
Re the 3rd qu am not sure that I see raised tgs levels as bringing about a positive hormetic effect. Raised tgs levels fuelling atherosclerosis is a one way process that the body can't recover from, from my understanding. Surely raised tgs for any length of time must have a negative effect in this area?

Thanks again and apologies if this post reads as argumentative