TL Health and Fitness Initiative 2011

On May 23 2011 06:03 MoonfireSpam wrote:

*disclaimer, this is recall from quite old knowledge back in biochemistry and preclinical days, haven't revised this stuff recently at all.

As far as I know the deal with cholesterol is that it is really damn complex and nobody really knows how it works. High levels of cholesterol are associated with atherosclerosis (coronary heart disease when it happens in the arteries supplying the heart). Atherosclerosis refers to the process by which fatty deposits are formed in the arterial walls, macrophages within the artery walls play a significant role by "eating" the oxidised versions of LDL/VLDLs (one of the reasons why antioxidants are good). I can't remember why LDL get oxidised more, I think it has something to do with them being saturated fatty acids. This keeps happening in a positive feedback system over time developing into the plaques. Diabetes increases the chances of LDL oxidation happening, and the insulin resistance that goes with it may increase LDL production by the liver, basically your body loses the ability to control cholesterol levels.

Here's the kicker which is what you are getting at. Your liver is capable of producing cholesterol and it really good at it since cholesterol also forms the base for every steroid hormone in the body. Due to this, your gut is also really good at absorbing cholesterol. And as such your gut and liver generally work as a tag team to maintain decent levels of cholesterol, if you stopped eating it, your liver would take over and if you eat lots, your liver till stop producing, so dietary intake has relatively little effect on blood cholesterol unless you are consuming silly amounts. And for that reason I would say that dietary cholestrol is neither good or bad as long as it isn't in excess.

TLDR: cholesterol ok. Diet shouldn't matter too much, just don't get diabetes, and stay fit.

If by PUFA you mean "poly-unsaturated fatty acid" then I think these are still considered to be good for you. I can't remember why they are good, but these are the things that are in fish oil /' omega-fatty acid supplements etc.

The processed oils you are talkng about are "trans-fats" or "hydrogenated fats" which are indeed bad for you and are associated with arterial disease.

A few bits on cholesterol:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2889993/?tool=pubmed
http://www.ncbi.nlm.nih.gov/pubmed/21385506
http://www.ncbi.nlm.nih.gov/pubmed/14571303

Edit: About the whole grain thing, I honestly would not take it too seriously. Gluten is only bad if you have coeliac disease. A quick pubmed search suggests whole grain products are more likely to be good than bad.
http://www.ncbi.nlm.nih.gov/pubmed/15162131 - Strong evidence suggests that whole grains among other carbs, fruits etc. are all good and managing and preventing diabetes.
http://www.ncbi.nlm.nih.gov/pubmed/16670693 - "The intake of wholegrain foods clearly protects against heart disease and stroke but the exact mechanism is not clear. Fibre, magnesium, folate and vitamins B6 and vitamin E may be important. "

TL Health and Fitness Initiative 2011 - Page 292