Many of my patients are so surprised when their triglyceride levels come back high after the spring and summer months.  They say they have been just as active as before and maintaining a relatively low fat diet.  Well, the diet part may be the snag.  For those of you new to this blog, it is the carbs and sugars that can affect one’s cholesterol profile adversely.  This has been scientifically proven for quite some time now.  

 

This has been confirmed in a recent study in JAMA.  This 6000 person study demonstrated that a high intake of added sugars is associated with increased risk for low HDL cholesterol (the good cholesterol) and high triglycerides.  Yes, it is now official.   

Even the American Heart Association is on the bandwagon as well.  They made a statement recognizing this fact and finally recommended against high intake of calories from sweets.  According to a statement published the journal Circulation ( April 2010), “A prudent upper limit of intake is half of the discretionary calorie allowance, which for most American women is no more than 100 calories per day and for most American men is no more than 150 calories per day from added sugars. 

http://circ.ahajournals.org/cgi/reprint/CIRCULATIONAHA.109.192627

My vegetarian patients are often confused how their seemingly healthy diet often results in an unhealthy  cholesterol profile.  Here is how it works:

 To review how carbs cause a dyslipidemic state:

1. glucose (sugar derived from carbs)  is passed through a corridor (the portal vein) and enters the liver.

2. The pancreas is paying very close attention to the molecules passing through this corridor into the liver and secretes insulin

3. Insulin stimulates the production of cholesterol by stimulating an enzyme called HMGcoA reductase ( the very enzyme that statin drugs try to inhibit!)

4. Insulin also slows down an amino acid called carnitine.  Carnitine is important because it functions to shepherd the fatty acids into the part of the cell where they will be converted into usable energy.  Insulin can therefore harbor weight gain by not allowing the fatty acids to be converted into energy effectively, via the mechanism of carnitine.

5. In the liver, the glucose is stored as glycogen. Because there is not that much glycogen in the liver, whatever sugar that it is can’t hold is spilled over to another processing system.  

6. The glucose is then packaged neatly into triglycerides.  

7. VLDL (very low density lipoprotein ) is then stimulated by the liver and LDL, the bad cholesterol) is made.  

When there is not much glucose in the body, as in the case in a lower-carb diet, there is no signal to release the insulin .  Insulin is absent (or low), glucose is not taken up by the cells and triglycerides are not manufactured from the spillover of glucose.  Therefore, the above process is not as robust.  With low insulin levels, the body begins to use fat as an energy source since it does not have the glucose. 

So there it is, eat low-carb and see cholesterol profiles improve.  

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