Bilirubin - another biomarker

This is a paper that @ConquerAging has recently promoted via twitter

It makes an interesting suggestion that low bilirubin could imply problems with CAC. The average Bilirubin of the participants was 10.9 mcmol/L ranging from 6.9-13.6.

Its not a biomarker I know a lot about and my own bilirubin has gradually reduced. Whether that is something to be concerned about or not is not necessarily clear.

Sadly the paper is behind a paywall. Looking at the chart of Bilirubin vs CAC, however, some of the really low bilirubin measurements are also associated with low CAC.

Hence it is only a factor. They also say it may not be relevant to non-Japanese. I would, however, think that it probably is similar for different ethnic groups.


Interesting. The conversion to US units is challenging. Do you know if the measurement is of “direct” bilirubin? My results don’t seem to be in the same range as the study participants despite being in the “normal” range.

The Molecular Weight of Bilirubin is AFAIK 584.66 g so 10 mcmol/L should be 584.66 mcg/dL.

This online conversion tends to agree (with a small conversion error)

If you give me the US values I will calculate an SI value.


Full paper:

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Mine just shows .5 mg/dl, so not very accurate but in range. Range on here is .2 - 1.2 so mine looks to be a little low.

Just got bilirubin measured and had CAC done (results will be ready in a week or so). Would be interesting to see the correlation.

Bilirubin Total
Your Value
0.4 mg/dL
Standard Range
0.2 - 1.0 mg/dL

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@John_Hemming here are my values. I’m not sure which bilirubin is the right one.


Total is what mine was and yours is at the top of the range. Also your ALP is 60. You’re going to live forever. Maybe I need to start working harder.


|Alkaline Phosphatas
Your Value59 IU/L
Standard Range35 - 104 IU/L

The lower the better?

Can you talk more re Alkaline phosphatase (ALP) - what is the longevity connection?

I would think it is the TO… figure (which I assume is total) That converts to 18.1 micromoles per litre. That is quite high.

I don’t know what that means.

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0.4 mg/dL is 6.84 microMoles per litre. (mcm/L) which is to the lower end.

As a matter of interest here are my most recent values in mcm/L
5.7 6.3 7 10 10.47 7 6.14 7.6 5.99 6.4

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ALP is used in the Levine formula on the basis that lower is better for mortality. When people have damaged livers ALP is higher which is where I think this comes from. My recent values are:

64 61 59 59 62 54 50 51 66 52 56

The lowest I have had was 49 and the highest 136.22 (which was a temporary high). I started out last year averaging around 75 and am now averaging around 60ish.

This is in IU/L which is the same in the USA and the rest of the world (apart from a few places that use something like kat and I don’t know what that is.)


Thanks John. I’m at a value of 58, but have never tried to impact it. Are there any strategies you have or think one can use to lower it?

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I don’t have a reference to the expected values of ALP by age. I don’t know your age. Hence I cannot say whether your figure is one worth reducing. Morgan Levine’s formula is driven by links to mortality, but there would be a point at which reducing ALP is potentially a sign of some form of damage.

My initial thought is that anything in the 50s is quite a good value and therefore not something to look at changing.

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Btw - there is a separate active thread on ALP and how supplementation for the gut might be good for aging:

I haven’t read up on this, but thought I just call it out

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With my latest results (from yesterday), says I’m 26yo biological (vs. 61yo chron). That’s a 2 year improvement since I started rapa (and other interventions). I’ll do Levine next…I need to get a hsCRP that show results below 0.3 (my last test result was 0.19).


@John_Hemming I don’t know either. shows a range of 0.0-1.2 mg/dl…my result of 1.1 is near the top. In total my result is a very good 26 yo (35 years below my chron age of 61)…i don’t know if the bilirubin is helping or hurting the score. I also don’t feel 26 yo so there’s that.


The problem with using ALP as a marker is that it is not specific. It is a combined value of ALP sourced from different areas of the body. And using it in this formula is therefore dubious. It is only relevant in basic blood work to the extent that if the total value falls outside the reference range, additional testing is needed to determine the source of the deviation, whether it’s bone, intestinal, liver. So if someone really wanted to track this over time as a marker, what they’d really want is a more comprehensive test with a breakdown. The test is “Alkaline Phosphatase Isoenzymes.”

This is an example report from Quest Diagnostics.

Marek Diagnostics offers the test through Labcorp for $25.

And for the intestinal value in particular, this actually falls with age. And you want to see this value remain higher. Supplemental ALP has been shown to extend lifespan in mice. As previously noted, there is a separate thread on that here.


My previous age prediction per was 53. Now it’s 40. It’s a big improvement.