Here is another of my occasional posts about how "myth busting" doesn't work.When you see someone offering to refute a "myth" with "facts," that's usually a sign that you're about to see an unhelpful, or even dishonest, argument. Not always and not necessarily, but usually.
For this post, I'll be talking about a "myth/fact" sheet offered by the American Heart Association about lipoprotein(a), or lp(a).
The American Heart Association offers a "myth/fact" sheet [PDF] about lipoprotein(a), or lp(a). In this case, it's less dishonest than it is unhelpful and perplexing--and clumsy. Read below the fold for more.
For the record, here's what you probably need to know, again, according to the American Heart Association. Lp(a) "is a cholesterol-carrying lipoprotein in your blood." It makes it more likely for LDL (bad) cholesterol to clog your arteries. If the amount of it is high, then you have a higher risk of heart attack or stroke. If it's low, you have a lesser risk. The level you have seems to be hereditary, and members of some racial groups are more likely to have higher levels. The levels also appear to be relatively fixed throughout your life, though certain life changes like menopause might affect them. Whatever causes liproprotein(a) levels, it's probably not what you choose to eat or how much you exercise.
Now, maybe lp(a)'s are more complicated than what the AHA says, and maybe some of what it says is in dispute or will be modified or recanted after more research. But I have enough trust in the AHA to presume that it's information is probably mostly accurate.
Even so, the "myth/fact" sheet it offers is just....not very good.
Before I go over it in detail, let me say that I find it hard to believe there are a lot of "myths" about lp(a), if by "myth" we refer to something that is commonly believed to be true but that is nevertheless false or otherwise inaccurate. Too few people, I wager, have even heard of lp(a) to harbor "myths" about it.
Strangely enough, before I looked into it this past week, I personally harbored some "myths" about lp(a). I had first heard about it maybe a year ago by reading some online article at, I believe, the Washington Post. I had thought that instead of being a lipoprotein, lp(a) was actually a form of cholesterol. I analogized it to the HDL/LDL distinction, where HDL is "good cholesterol," LDL is "bad cholesterol," and lp(a) is "a really bad type of LDL." (In fact, I got it into my mind t it was called LDL-a and not lp(a).) In fact, lp(a) seems to be something distinct from "cholesterol." (Here I'm in uncertain territory. I have a hard time grokking the difference between cholesterol and lipoprotein.) While I (vaguely) remember reading that medications don't reduce lp(a), I somehow came away from whatever article I read with the notion that diet and exercise could reduce it.
So those were my "myths." Some of the "myth/fact" items are informative But many of the "myths" are probably myths ore are unrefuted by the proffered "fact."
Myth [#1]: If my LDL (bad) cholesterol level is normal, I don’t need a lipoprotein(a) test.
Fact: LDL (bad) cholesterol and lipoprotein(a), or Lp(a), are different. A lipid panel, or standard cholesterol test, doesn’t measure Lp(a). You can have normal LDL and still have high Lp(a). To know your level, your health care professional must order a separate Lp(a) test.
That's a good thing to know. While I'm not sure how many people know enough about lp(a) to believe they don't need a test, it's good to know the benefits of the test and the risk of not having one.
Myth [#2]: Lp(a) doesn’t affect my heart health.
Fact: If you have a high Lp(a), your risk for heart disease and stroke can increase. Knowing your level helps you take early steps to protect your heart and brain health.
A little redundant to the first "myth," but I suppose that's informative enough.
Myth [#3]: I don’t have any symptoms, so my Lp(a) must be fine.
Fact: You may have high Lp(a) and not know it because it usually has no symptoms. New guidelines recommend that every adult be tested at least once in their lifetime. Testing is especially important if you have:
• Family or personal history of premature heart disease (under 55 for men and under 65 for women)
• Known family history of high Lp(a)
• Diagnosis of familial hypercholesterolemia (FH), an inherited condition in which people may be born with very high LDL level
Also redundant to the first point, but notice a contradiction here. The second "myth" in the list says "my bad cholesterol is normal, so I don't need a test," this myth #3 is partially "refuted" by the point that people with a very high bad cholesterol level should "especially" take the lp(a) test. The apparent contradiction can be easily resolved, and anyone reading the list knows what the AHA means here. But it's still very clumsy.
Myth [#4]: High Lp(a) isn’t passed down in families.
Fact: Your level is mostly inherited, and when it is high, it can increase your risk of heart disease and stroke. If your Lp(a) level is high, cascade screening is recommended. This means testing your close family members, including your parents, siblings, and children to find others who may be at risk.
Again, important to know. I just don't believe enough people think about lp(a) enough to harbor the "myth" that lp(a) isn't somehow hereditary.
Myth [#5]: Lp(a) doesn't affect everyone the same, including me.
Fact: Some factors can affect your Lp(a) level. Your level may be higher if you are of African or South Asian background, during life stages like pregnancy or menopause, or if you have kidney, liver, or thyroid disease
The fact here actually reinforces the "myth." It doesn't refute it at all. The "myth" is that lp(a) "doesn't affect everyone the same," and the "fact" is lp(a) doesn't affect everyone the same. For example, it can affect the following people differently: people of African or South Asian background, or people during life stages like pregnancy or menopause, or people with kidney, liver, or thyroid disease.
Myth [#6]: I can lower my Lp(a) with healthy food and regular physical activity.
Fact: Even though lifestyle changes don’t lower Lp(a) levels, there is a lot you can do to support your heart health. You can lower your risk of heart disease and stroke by:...." [I've left out the long list of suggestions. If you'd like to see them, feel free to look over the sheet yourself.]
I was tempted to repeat my "it's useful to know, but it's not really a 'myth'" mantra. But I should give a half-point to the AHA sheet here. It warns against fatalism that a high score might inspire. It also (obliquely) warns against overconfidence for those who have a low score. I had my lp(a) tested a week ago and fortunately, it's very low. It's hard to avoid the sensation of, "well I have nothing to worry about." But heart disease runs in my family, even if their lp(a) levels are low. (I don't know if they are low, but my test suggests it's possible.)
Myth [#7]: Health insurance doesn’t cover Lp(a) testing.
Fact: Most insurance plans cover this test. When you call to check, mention CPT code 83695. If your plan doesn’t cover it, your health care professional may be able to point you toward more affordable testing options.
Yes. Useful to know, but probably not a "myth."
Before parting, I'd like to return to myth #6 above, the one to which I gave a "half point" to AHA for stating that despite one's lp(a) score, people should still be vigilant about how they take care of themselves. I must temper my half point with a concern. Something seems...not off...but a little too neat and tidy.
The AHA has a very strong incentive to say that despite a high score, there's still something people can do. That's the type of thing public health organizations say whether it's true or not. It's likely not wrong. But I speculate that it perhaps is debatable, or at least debatable enough that the conversation needs to go further. Perhaps diet and exercise does help, but there's still likely some things we don't know. We all have to balance what we don't know against what we do. Framing certain views as "myths" easily countered with undisputed and undisputable "facts" forestalls conversation. Without acknowledging what is unknown and debatable, the AHA--and not just the AHA, but public health agencies generally--tend to undermine confidence in what they say.
Currently, the highest levels of U.S. government promote "alternative" approaches to public health that in their own way raise serious concerns. Those approaches have a strong constituency among the U.S. population. Maybe, just maybe the appeal of those approaches owes something to the fact public health agencies operate in that way.
Myth busting doesn't work.
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