I was in bed, reading the BBC’s website on my iPad using their ultra cool application, when I came across an article showing new research linking blood fats with heart disease. The link to that article is here.
First, I should point out that there’s never really been a definitive link between high fat diets and heart disease. That comes as a surprise to a lot of people, mainly because it’s recited over and over so often as to be the conventional dogma. But research has never really backed that up in any capacity.
There is a mild link between cholesterol and heart disease, but it’s often misconstrued in the press based on a lack of understanding about how cholesterol works. There are many people with high cholesterol that don’t have any heart disease, and many people with low cholesterol that have advanced heart disease. While research is obviously still ongoing, it looks more and more likely that it’s the nature of the cholesterol, and not the amount, that matters.
With regards to the article, there are a few things I want to clarify for the lay reader.
Cambridge University researchers looked at the role of triglycerides, which is produced in the liver and derived from foods such as meat and dairy products.
As usual, the author purposefully implicates the two food groups above (meat and dairy products) that lead the reader to conclude that it’s probably fat which is the cause. Which is actually ironic given that the main source of triglycerides in the body are from dietary carbohydrates.
This is pretty old news to me, given how much I read in the area. One of the most important (and useful) metrics for predicting heart disease is the ratio between triglycerides and high density lipoprotein (HDL) cholesterol. The lower the number, the less of a chance there is for someone having or developing heart disease. That ratio can also be used as an indirect measure of the type of VLDL cholesterol (one that’s often not mentioned or ever screened for), which is the type that’s ultimately implicated in causing heart disease. As the TRIG:HDL ratio goes up, more and more of the VLDL cholesterol is small and dense, which can cause it to plug up arteries and form arterial plagues. As the ratio goes down, more and more of the VLDL cholesterol becomes large and fluffy, easily scavenged from the blood before causing a lot of harm.
That ratio can be improved by two things: lowering triglycerides or raising HDL cholesterol. Lowering triglycerides can be accomplished by reducing dietary carbohydrates or by eating carbohydrates with a lower glycemic index. HDL cholesterol is raised by exercise, weight loss, and strangely enough, by eating most types of fats.