Cholesterol Esters: The Real "Bad" Cholesterol?

Ah cholesterol, the much vilified nutrient!  If we listen to most of the traditional nutrition and health information out there we are forced to think that cholesterol is extremely bad for us and should be avoided at all costs.  However, as many of you may know already, cholesterol is essential for human life.  It is a major component of all of our cellular membranes and is the precursor to many hormones we need (1).

Also frequently mentioned are the different types of cholesterol, the so-called “bad” cholesterol, LDL, and the “good” cholesterol HDL.  However, calling these two transport molecules cholesterol is really a misnomer, as they are complexes containing many different types of proteins, fatty acids, and only a portion of it is actual cholesterol.  These two molecules have different functions in our body, and can come in a variety of sizes.  However, labeling them “good” and “bad” cholesterol is incorrect and misleading.

So is there actually a “bad” form of cholesterol?  I have already said that cholesterol is essential for life, but there is a type of cholesterol that does appear to be bad for us.  This type of cholesterol is cholesterol esters, which is just a cholesterol molecule attached (esterified) to a fatty acid. Not all cholesterol esters are equal though, ones that are attached to polyunsaturated fatty acids (PUFAs) appear to be the most dangerous.

Ketosis VI: Therapeutic Roles

We have covered most of the hardcore science that I wanted to review when looking at ketosis and ketogenesis.   We have covered most of the relevant biochemistry in terms of how are ketone bodies formed and how they are regulated.  That is all well and good, but I am sure many of you are just wondering how ketosis can benefit you, right?  Well, this article is meant to show you some of the benefits for ketosis. 

Ketogenic diets have been used as therapeutic diets for some conditions for over a century, and while it isn’t used as much anymore, it probably should be.  This article will mainly go over how it can help out those in a disease state; however, I think the mechanisms through which ketones act in the diseases show us some of the power of these energy molecules.  You many not have one of these diseases, but seeing how much they can help with certain conditions certainly makes you think twice about them.

Ketosis IV: Cellular Regulation

As we have seen already the control of ketosis is controlled through a variety of mechanisms in our bodies. And, most importantly, many of these mechanisms are intricately tied to our bodies’ own energy sensing pathways. We have seen ketosis regulation at a variety of levels throughout our bodies.  It can be controlled through conscious action, by eating a high-fat diet or fasting.  It can be controlled throughout our internal environment by hormones and other signaling molecules like insulin and glucagon.  And now we will go down a bit farther even, and look at how ketosis is controlled at the cellular level.  Again this one will be a technical article, so as always if you have questions post them to comments!

Benefits of Intermittent Fasting

We are going to take a quick break from our regularly scheduled programming because I just stumbled upon this new study from FASEB. The study is titled "Timed high-fat diet resets circadian metabolism and prevents obesity".  The wording "Timed high-fat diets"  is kind of confusing, but if you read the paper what they did was an intermittent fasting protocol.  Rats were separated into one of 4 different groups: an ad libitum low-fat diet (AL-LF), an ad libitum high-fat diet (AL-HF), a restricted feeding low-fat diet (RF-LF), or finally a restricted feeding high-fat diet (RF-HF).  The restricted feeding group was only allowed to eat for 4 hours/day, while the ad lib groups could eat whenever they want.

The results were pretty striking.  The RF-HF mice consumed the same amount of calories as the AL-LF mice, but had a 12% reduction in body weight compared to them.  Also, the RF-HF mice also had lower cholesterol levels, higher insulin sensitivity, and lower inflammatory markers than all the other study groups.  The RF-HF mice also showed signs of improved lipid oxidation, showing that the fat they consumed ended up being burned for energy, and not stored.  Not to mention that the HF diet was based on soybean oil and these are mice that are predisposed to become obese on a high-fat diet.  Finally you might think that these researchers were starving these mice on the RF protocols, but the RF-HF mice had lower ghrelin, indicating a higher degree of satiety.

A lot of people think that the benefits of intermittent fasting come from reducing calorie intake due to the small eating window.  However, this study shows that even if you eat the same amount of food, and pretty crappy food at that, eating in an IF way can help you improve your health.  I have found that I naturally tend to eat in a restricted feeding type way, with most of my eating happening a 6 to 8 hour window just naturally.  I just thought this was a pretty interesting study and showed some of the very powerful benefits of IF protocols for health.

A human need for fiber?

Well after attending AHS 2012 the other week I came home with more questions then I could have imagined going into it.  All of the presentations were fantastic, however the safe starches panel seems to be the most talked about.  This was very interesting, as it seemed like the panelists covered almost the entire spectrum of a carbohydrate intake continuum.  Another point that was brought up was the need for dietary fiber, and, being somewhat unsure about this topic, I decided to dig a little further into it.