Sunday, February 27, 2011

When being fluffy is a good thing

Last week a headline on the BBC website informed us that "Cholesterol does not predict stroke in women".   The gist of a recent Danish study quoted in the article was that triglycerides are a more effective predictor than LDL measurements.

What I found stunning about this headline is that scientists have been aware of the limitations of cholesterol measurement since the 1950's.  The public, on the other hand, is bombarded with regular messages to reduce their "bad" or LDL cholesterol, and increase HDL or "good" cholesterol. 

What is not commonly known unless you dig deeper into the nutritional scientific literature, is that there are different classes of lipoproteins, which can be fractionated according to their density:  smaller LDL particles, known as VLDLs (very low-density lipopoteins), are more atherogenic in nature.  Because they are smaller, they can more easily form plaque in the arteries, leading to blockages that increase stroke and heart attack risk.  Triglycerides are a major component of these VLDLs.

Some people have a relatively higher concentration of large, fluffy LDL particles in their blood stream and these are not as harmful as their dense brethren.

This explains why a high LDL reading that isn't broken down any further is not a good risk predictor.

I was very interested to read the abstract of the study itself.  In my opinion, it imparts a subtly different message:
Current guidelines on stroke prevention have recommendations on desirable cholesterol levels, but not on nonfasting triglycerides. We compared stepwise increasing levels of nonfasting triglycerides and cholesterol for their association with risk of ischemic stroke in the general population.
What is going on here?

From what I can see, the study simply suggests changing the guidelines to provide reference ranges for triglyceride levels.  

That's very different than announcing, in 2011, that cholesterol is a useless measurement tool.  However, I do think the BBC headline was dramatic enough to attract my attention, while a more accurate one may have been almost too boring to look at.  Besides, maybe it's time to inform the public that knowing your cholesterol level is only of marginal relevance.

3 comments:

  1. I agree I now "crave" a salad full of fresh vegetables, I have no problem walking past cookies or muffins and having that "trigger" go off in brain that says I have to eat that cookie.

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  2. Sorry the above post was meant for the baking post.

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  3. That's ok, Lorie, we can continue the discussion here too. I suspect the ability to say no to a temptation can only be achieved when you *totally* stop consuming sugar and grains, though I may be mistaken.

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