I'm just saying that, to simplify the math enormously, if you have 20 test groups then one of them is very probably going to return a p<.05 result that is due to random chance. [MR's added emphasis]
Right: that's a variation on the problem of multiple comparisons. But as you indicate, that is likely to generate false
positives, not false
negatives. As I said, "Having multiple groups shouldn't really have
any effect on the false negative rate."
I was thinking Metformin also extended lifespan, but I don't know how strong the science is behind that.
Metformin "extends lifespan" in genetically cancer-prone and/or sick, ill-cared for mice. In normal, healthy mice, it increases
life expectancy by 5%: that's not an extension of
lifespan.
there may be a reason why they don't seem to "work". Spindler is a genius at mouse husbandry, and knows how to make mice live longer than most everyone else seems to be able to accomplish. In many of the published studies (by others), the life extension, if not due to crypto-CR, is apparently compensating for poor husbandry. So... Assuming these results have any bearing whatsoever on human lifespan (very large assumption), and knowing how poorly husbanded most humans are, why shouldn't the poor husbandry-compensation results be interesting (if not applicable) to us?
First, it only
seems that Spindler is a genius at husbandry because (a) so few people do lifespan studies at all, (b) most people who do lifespan studies are sloppy, rank amateurs with no experience in lifespan studies and do things like let their animals eat themselves sick and fat, and ( c) many groups
intentionally use disease-prone strains of mice (the McMaster nonsense, most of the nonsense coming out of Russia) and/or
intentionally bugger up their otherwise-healthy mice (the original resveratrol mouse study, in mice fed a high-fat, high-sugar diet leading to diabesity). Then when their lifespan is
mostly normalized by their intervention they speak as if (or the media or the supplement industry speaks as if) this tells you something about its potential in
normal, healthy people. The media and less-than-rigorous researchers at least tend to include the caveats; supplement hawkers are even more breathless about
the tantalizing potential, or omit the caveats altogether.
Plenty of people can raise normal, healthy mice: Spindler, Weindruch, Walford (when he was alive), the three groups running the NIA's ITP (though one of them is not as good as the other two), de Cabo, Bartke, etc. And note that "despite" their healthy mice, these groups have shown multiple interventions that extend LS: rapamycin, CR, IGF-1 pathway mutations.
Second: middle-class Americans taking any care of themselves at all are at least as well-cared-for as these mice.The US population includes a lot of smokers, people living in terrible working conditions, the poor, people who are murdered, people eating less than one vegetable a day, and people with no health insurance, and yet the survival curve for the USA as a whole still looks nearly as good as that Spindler's mice. If you don't smoke, don't have a BRAC1 mutation, aren't obese, eat a few vegetables, have and use health insurance, and get any exercise, you're at least as well-husbanded as Spindler's mice.
"Death", or longevity alone, is kind of a dumb endpoint. It's not really what I care about. I don't want the final ten years of my life to be spent confused, drooling, and incontinent. I'm extremely interested in healthspan. It does of course seem likely that these two endpoints will correlate, but they aren't the same. I'd like to see more attention paid to healthspan, but of course it is a more difficult thing to measure.
I agree -- but OTOH, robust, healthy mice don't just drop dead. Lifespan studies demonstrate that the animal is well enough to live, and
maximum lifespan tells you something about the rate of aging. And again, multiple interventions that extend LS (rapamycin, CR, IGF-1 pathway mutations)
do extend healthspan on multiple parameters. Slowing the rate of aging is required to extend maximum LS, and slowing the rate of aging (ceteris paribus) extends health.
"Supplements" is a rather broad term. Are we putting "Bone Restore" in the same category as C60?
Well, no -- C60 is not a supplement.
Speaking of C60, why exactly does the published literature showing desirable biological activity in multiple species, not to mention radical life extension in a mammal, seem to not exist as far as this discussion is concerned?
I'm only aware of one study claiming benefits in normal, healthy mammals.
Finally, there's the multibillion dollar supplement industry, with no shortage of hucksters who are willing to let people believe anything, including actively encouraging them to believe things that aren't true. In some circles, this is known as "lying". If Spindler's goal is to shoot those guys down, that's ok with me.
I honestly think he just wants to get to the truth -- and his
sponsor, and the people who recommended things for him to try (myself included), all wanted to find things that work.
But yes: when he helps to catch people in lies (and also in just pushing things on flimsy evidence), it makes me happy. Just not as happy as discovering that metformin extends lifespan in normal, healthy mice by 40%
would.
http://www.scienceda...31230135106.htm
Most Clinical Studies On Vitamins Flawed by Poor Methodology
Many projects have tried to study nutrients that are naturally available in the human diet the same way they would a powerful prescription drug [which is, in effect, what the supplement hawkers claim that they are -MR]. This leads to conclusions that have little scientific meaning, even less accuracy and often defy a wealth of other evidence ... Such changes are needed to provide better, more scientifically valid information to consumers around the world who often have poor diets, do not meet intake recommendations for many vitamins and minerals, and might greatly benefit from something as simple as a daily multivitamin/mineral supplement.
Needed are new methodologies that accurately measure baseline nutrient levels, provide supplements or dietary changes only to subjects who clearly are inadequate or deficient, and then study the resulting changes in their health. Tests must be done with blood plasma or other measurements to verify that the intervention improved the subjects' micronutrient status along with biomarkers of health. And other approaches are also needed that better reflect the y.different ways in which nutrients behave in cell cultures, lab animals and the human body.
All emphasis mine. Agreed! If supplement companies marketed on that basis, I would have no problems with them. I supplement this same way myself, along with
some relatively modest, more experimental things (and these days, almost all within normal dietary intake).
I am 59, and I am similar. Except that I did not really start taking care of myself and taking a range of supplements till three years ago. [...] A lot of [my health improvement] is to do with taking off weight and getting to a normal BMI; but some must be due to what I eat or supplement (or what I don't eat--namely junk). I do worry that supplements could be doing me harm, as the studies quoted suggest; but then I ask myself: what is a supplement? I mean, I eat dried fruits to help my bowels--does that not make them a supplement? I eat greens every day for my health, even though I do not like them much. Are they a supplement? Some of the supplements I take are really just a form of food: garlic, turmeric, green tea, kelp, cherry extract. Where is the line drawn?
The line can certainly begin to be drawn by looking at the levels one could realistically get from a healthy diet. Ie, when evidence accumulated that high intakes of gamma-tocopherol FROM FOOD
might prevent prostate cancer, it would have been non-crazy to start offering people who don't get much gamma-tocopherol in their diet (in particular, who consume no soy or soybean oil) supplements matching the intakes of high dietary consumers. But that would mean
twenty milligrams (or less, since even low consumers don't get
zero milligrams), not
325 mg plus other nutrients designed to elevate your blood levels!
Sure, some supplements might cause a little harm, but that is true of some of the food we eat too.
Yes, but you can get evidence on that question in the epidemiology. What supplement hawkers routinely do is say "people who get "a lot" of Nutrient X from
foods (that also contain many other things) have lower risk of disease Y! Let me sell you an
isolated pill that contains
ten or twenty times that much Nutrient X, and you can take it blind for twenty years! Then, if a clinical trial or animal study refutes my optimistic sales job, I will deny, deny, deny, or (since the competition has been undercutting me for years on Nutrient X anyway) move you on to my newer, better Nutrient X
+1!"
To paraphrase the outgoing mayor of New York: "This is your
life, people!
Don't screw it up."
Edited by Michael, 31 December 2013 - 03:31 PM.