It's all about asking the right question: What PUFAs do to destroy our health

I recently found this interesting study that takes a mouse model that is genetically predisposed to diabetes, and gives them either a "control" diet, or a a diet high in long chain-monounsaturated fatty acids (LC-MUFAs) (1).  The results they gather are very interesting in their own right, but I'd like to take a different approach to looking at this study than the authors did.

This blog is all about how we can maintain optimal health using evolutionary principles, hence the name.  As you may have noticed in the previous paragraph I put control in quotation marks, and this was for a very specific reason.  The control diet in this experiment was a diet that supplied 7% of all energy in the form of soybean oil, of which over 50% was omega-6.  However, the intervention diet, contained only 3% soybean oil, and 4% was LC-MUFAs, and almost NO omega-6's.  However, for each diet it was only this 7% of energy that supplied by fatty acids.  We can see a breakdown of the fatty acids in both diets in the following table.

If we look at these two fatty acid compositions through an evolutionary perspective, it is hard to argue that a soybean oil diet is a control condition.  So let's flip this study on it's head.  Instead of looking at the results as "how does a high LC-MUFA diet IMPROVE the health of diabetic mice" we will instead ask the question "how does a high PUFA (specifically omega-6's) diet RUIN the health of diabetic mice".  We can use all the same results, we will just look at them a bit differently.  Science is, after all,  all about asking the right question!

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.