Biomarkers That Actually Matter vs. Expensive Noise

The Problem With Testing Everything

More Data Doesn't Mean Better Health

There's a billion-dollar industry built on a simple and deeply appealing idea: the more you know about your body, the healthier you can be. And look, I get it. When you're handed a report with 80 values and your name on the top, it feels like personalized, cutting-edge medicine. It feels like you're ahead of the curve.

But here's the uncomfortable truth - most of it is noise.

That's not me being cynical. It's what the evidence actually shows. The vast majority of biomarkers being sold to health-conscious people today are biologically real, but clinically useless. There's a big difference between a marker that correlates with something bad happening and one that actually tells you what to do about it. That gap is where a lot of your money disappears.

The Three Questions Every Test Should Answer

Before we get into specifics, there's a useful way to think about any biomarker. It needs to clear three hurdles:

First, does the test actually measure what it claims to measure, consistently? Second, does the result connect meaningfully to your health outcomes? And third, this is the big one, does knowing the result actually change what you or your doctor does, in a way that makes things better?

Most tests pass the first question. A lot fail the second. Almost all of the trendy ones crash out on the third.

Take homocysteine as an example. Elevated homocysteine is linked to cardiovascular risk, the mechanism makes sense, the test is solid. Sounds great, right? Except that when researchers ran actual clinical trials giving people B vitamins to lower their homocysteine, cardiovascular outcomes didn't improve. At all. Multiple large trials, same result. Homocysteine wasn't causing the problem, it was just tagging along with something that was. Measuring it gives you the feeling of insight without the actual insight.

The Tests That Are Actually Worth Getting

So what does hold up? More than you'd think in some areas, less in others.

Your cholesterol, but go deeper than LDL

LDL cholesterol has been around forever, and some practitioners have started treating it like old news. It isn't. The evidence that LDL drives heart disease is about as bulletproof as it gets in medicine. But here's where it gets interesting: standard LDL cholesterol can lie to you. In people with insulin resistance, metabolic syndrome, or those eating very low-carb diets, you can have a perfectly normal LDL-C while your actual particle count; the thing that actually clogs arteries, is dangerously high.

That's why ApoB is becoming the smarter metric. One test, doesn't require fasting, captures all the dangerous particles at once. If you're getting a lipid panel, push for ApoB.

Lp(a) — the test most doctors never order

Lipoprotein(a), or Lp(a), is one of the most underused tests in routine medicine, and it genuinely shouldn't be. Your Lp(a) level is almost entirely genetic, diet and most medications barely touch it, and it's independently linked to heart disease, aortic stenosis, and arterial disease. Most adults have never had it checked.

The reason to test it isn't that we have a magic treatment for high Lp(a) right now (though some promising therapies are in late-stage trials). It's that knowing your level can legitimately shift how aggressively you manage everything else. That's a test that changes clinical decisions, which is exactly the bar we're trying to clear.

HbA1c and fasting insulin together

HbA1c is a standard diabetes marker and it's fine for what it does. The problem is that it's a lagging indicator, by the time it starts creeping up, you've often had insulin resistance for a decade. Fasting insulin (or HOMA-IR, which combines fasting glucose and insulin into one score) catches metabolic dysfunction much earlier in the process.

Fair warning: fasting insulin doesn't have a perfectly standardized reference range, and different labs report it differently. That's a real limitation. But a very high fasting insulin alongside normal glucose and HbA1c is still telling you something important; your pancreas is working overtime to keep blood sugar normal, which is pretty much the definition of insulin resistance. The two tests together paint a much better picture than either alone.

hsCRP — useful, but not in isolation

High-sensitivity CRP is one of the few inflammation markers backed by hard clinical trial data. Research has shown both that statins reduce heart events in people with elevated hsCRP, and that directly targeting inflammation reduces cardiovascular risk. So inflammation matters, and hsCRP can capture it.

The catch: CRP goes up with basically any inflammation; a cold, a flare-up of an old injury, carrying extra weight, poor sleep. One high reading in isolation means almost nothing. It's most useful as part of a broader risk picture, not as a standalone alarm bell.

The Tests That Are Mostly Expensive Anxiety

Here's where I'll probably annoy some people in the functional medicine world.

Big hormone panels in healthy people

Checking testosterone, DHEA, estradiol, cortisol, pregnenolone, and a dozen other hormones in someone without specific symptoms is very hard to justify. The reference ranges are inconsistent between labs, these values swing wildly depending on time of day, sleep, and stress, and "treating to a number" rather than treating actual symptoms has a pretty poor track record.

The one clear exception: testosterone in men with genuine symptoms of low T and consistently low morning levels. That's legitimate. What's less legitimate is the "hormone optimization panel" being sold to people who feel "kinda tired sometimes."

Massive micronutrient panels

Testing vitamin D in someone who's at risk? Sure. Running a 40-marker intracellular nutrient panel through a specialty lab? The validation data is thin, the reference cutoffs aren't well-established, and reproducibility between labs is a known issue. The underlying idea, that tissue-level nutrient status matters, is reasonable. But "sounds reasonable" isn't "clinically validated."

Shotgun autoimmune screening

Tests like ANA are real and useful for diagnosing specific autoimmune conditions. The problem is ordering them in people who just feel fatigued and achy with no strong clinical suspicion. ANA comes back positive in up to 25-30% of perfectly healthy people at low titers. Order it broadly and you'll generate anxiety, specialist referrals, and sometimes unnecessary treatment, all based on a result that was probably a false positive from the start.

Urinary organic acid panels

These panels claim to reveal dysfunction in mitochondrial function, neurotransmitter metabolism, and B vitamin status through urine metabolites. They use scientific-sounding language and look very impressive. But outside of specific rare metabolic disorders, the clinical validation for using them in general populations is essentially absent. This is an area where the vocabulary of science gets used to dress up what is fundamentally an unvalidated practice.

What's Actually Worth Watching (But Not Ordering Yet)

Not everything new is snake oil. A few emerging markers are genuinely exciting, they're just not ready for routine use.

GlycA is a composite inflammation marker measured through the same NMR test as LDL particle number. Early data suggests it predicts cardiovascular disease and diabetes better than CRP and doesn't spike as much with minor infections. Interesting, but no interventional trials yet showing that acting on it improves outcomes.

Polygenic risk scores might be the biggest shift coming to preventive medicine. By aggregating thousands of tiny genetic variants, these scores can identify people at dramatically elevated lifetime risk for heart disease, diabetes, and certain cancers, risk that's largely independent of traditional factors. You test it once, it doesn't change, and it can flag high-risk individuals early enough to do something about it. The American Heart Association is already starting to incorporate genetic risk into its guidelines. Watch this space.

Liquid biopsy for cancer (catching tumor DNA circulating in the blood) is advancing fast. Multi-cancer early detection tests are generating real excitement. The challenge is that sensitivity for early-stage cancers, where early detection actually matters most, is still limited, and the clinical utility question isn't fully answered yet. Getting this wrong means a lot of people getting frightening, inconclusive results with no clear next step.

Why Bad Tests Keep Getting Ordered

None of this is just about scientific confusion. The incentives are deeply broken.

Lab companies get paid per test. Functional medicine practices differentiate themselves through comprehensive testing. Patients who are anxious about their health find comfort in numbers, even meaningless ones. And there's the illusion of personalization: a report with 80 values feels individualized in a way that a standard lipid panel doesn't.

But real personalization means the data changes what you do in ways that improve your health. A panel where 75 out of 80 results don't affect any decision isn't personalized medicine, it's personalized-feeling medicine. Those are very different things.

A Simple Rule of Thumb

When you're looking at any test, ask yourself one question: if this comes back abnormal, what would actually change?

If the honest answer is "not much" or "we'd probably order more tests," that's your sign. And the follow-up question: has treating an abnormal result for this marker actually been shown to improve real outcomes, not just move the number, but reduce disease or mortality?

LDL lowering passes that test easily. Homocysteine lowering does not. Most comprehensive functional panels have never even been evaluated at that level.

The biomarkers that genuinely matter tend to be causally involved in disease, have reference ranges built on outcome data, measure consistently across labs, and link to interventions that actually work. That's a short list. Most of what gets sold to health-conscious people doesn't make it onto that list.

Curiosity about your health is a good thing. But the feeling of having comprehensive knowledge and actually having actionable insight are not the same thing, and the gap between them is costing people a lot of money, and sometimes causing real harm.