3 ms·

Is the article wrong in stating "UA stimulates mitochondrial biogenesis". Did the measurements of acylcarnitine levels not actually show this? Have any other su

Is the article wrong in stating "UA stimulates mitochondrial biogenesis". Did the measurements of acylcarnitine levels not actually show this? Have any other substances been found to affect acylcarnitine levels or stimulate mitochondrial biogenesis ?

gbrown 7y ago
That's orthogonal to the point you're responding to - the point is that while this is a promising avenue for research, it does not provide evidence of a meaningful effect on the actual outcome of interest: aging/longevity. The point of a biomarker is that we think/hope/hypothesize that we can use it as a surrogate for the thing we're actually interested in, so that we have something measurable on shorter timescales. Unfortunately, this assumption is often incorrect, and we won't actually know for years.
- strainer 7y ago
  I'm questioning the idea that this particular biomarker - doesn't actually mark what the report claims it marks (mitochondrial bio-genesis). How do we often test for diabetes.. cancers.. many many clinical conditions? Biomarkers. So they are not practically unreliable in general. What do you know about the particular biomarker employed in the study to say that it is unreliable ?
  - gbrown 7y ago
    1. Each biomarker has to be validated independently. 2. There's a huge difference between something used for testing, and something used for intervention. Grey hair is a pretty OK test for aging, but clearly dying it isn't going to arrest the aging process. Long term degenerative conditions are some of the most difficult problems for such validation, due to time, cost, and the complexity of risk in real populations. I don't know anything about how well the current study actually links to mitochondrial biogenesis, but I know that we don't have satisfactory interventional biomarkers for a process as complex as aging. By all means continue researching this, but I think it's eminently sensible to be skeptical at this point.
    - strainer 7y ago
      Be as skeptical as you wish, but that is all very orthogonal to my requests to substantiate claims here that the biomarker examined is unreliably interpreted. They have not been substantiated. Discussion of what qualifies as "anti-aging" is another matter . Anti-aging is not a clinical term, there have been no claims made about general reversal of aging.

gbrown 7y ago

That's orthogonal to the point you're responding to - the point is that while this is a promising avenue for research, it does not provide evidence of a meaningful effect on the actual outcome of interest: aging/longevity. The point of a biomarker is that we think/hope/hypothesize that we can use it as a surrogate for the thing we're actually interested in, so that we have something measurable on shorter timescales. Unfortunately, this assumption is often incorrect, and we won't actually know for years.

strainer 7y ago
I'm questioning the idea that this particular biomarker - doesn't actually mark what the report claims it marks (mitochondrial bio-genesis). How do we often test for diabetes.. cancers.. many many clinical conditions? Biomarkers. So they are not practically unreliable in general. What do you know about the particular biomarker employed in the study to say that it is unreliable ?
- gbrown 7y ago
  1. Each biomarker has to be validated independently. 2. There's a huge difference between something used for testing, and something used for intervention. Grey hair is a pretty OK test for aging, but clearly dying it isn't going to arrest the aging process. Long term degenerative conditions are some of the most difficult problems for such validation, due to time, cost, and the complexity of risk in real populations. I don't know anything about how well the current study actually links to mitochondrial biogenesis, but I know that we don't have satisfactory interventional biomarkers for a process as complex as aging. By all means continue researching this, but I think it's eminently sensible to be skeptical at this point.
  - strainer 7y ago
    Be as skeptical as you wish, but that is all very orthogonal to my requests to substantiate claims here that the biomarker examined is unreliably interpreted. They have not been substantiated. Discussion of what qualifies as "anti-aging" is another matter . Anti-aging is not a clinical term, there have been no claims made about general reversal of aging.