Sugars raise bad fats in the blood

Readers and patients here know how higher levels of insulin from a high glycemic diet can result in an increase in the harmful kinds of fat in the blood. It will come as no surprise that a paper just published in the Journal of the American Medical Association adds more evidence to the association. The the objective of the authors was to...

"...assess the association between consumption of added sugars and blood lipid levels in US adults."

They analyzed the data for 6,113 adults collected over seven years for sugars in the diet and levels of HDL and LDL cholesterol and triglycerides. A clear correlation between higher levels of sugars and lower HDL ("good" cholesterol), higher LDL ("bad" cholesterol) and higher triglycerides emerged. There was strong evidence for maintaining a low glycemic diet to regulate cholesterol:

"Among higher consumers (≥10% added sugars) the odds of low HDL-C levels were 50% to more than 300% greater compared with the reference group (<5% added sugars)."

Their conclusion was mildly stated:

"In this study, there was a statistically significant correlation between dietary added sugars and blood lipid levels among US adults."

Have you been trying but not succeeding in getting cholesterol and/or triglycerides down with a low fat diet? There has been so much science done on the correlation between insulin sensitivity and cholesterol levels; it's surprising this wasn't noted by the authors. Just one example is a fresh paper in the Journal of Lipid Research that begins with the well-known fact:

"Cholesterol synthesis is upregulated and absorption downregulated in insulin resistance and in type 2 diabetes."

Interestingly, the authors wanted to see if any level of insulin resistance would have an effect on cholesterol synthesis:

"We investigated whether alterations in cholesterol metabolism are observed across the glucose tolerance status, from normoglycemia through impaired glucose tolerance to type 2 diabetes..."

What conclusions did they draw from their data?

"In conclusion, cholesterol metabolism was altered already in subjects with impaired fasting glucose. Upregulated cholesterol synthesis was associated with peripheral insulin resistance independent of obesity."

How to eat healthy fat and oil is another topic, but if cholesterol and triglycerides are the issue—pay attention to sugars and insulin.