3 ms·

Hand grip strength. Pretty much all other measures of frailty - such as muscle mass. Time spent jogging. Time spent not sitting. Time spent being active. All o

Hand grip strength. Pretty much all other measures of frailty - such as muscle mass. Time spent jogging. Time spent not sitting. Time spent being active. All of these correlate well with mortality. Causation is harder to prove on these longer timescales. e.g. more likely to be strong and exercising because you are more robust, or more likely to be more robust because you are strong and exercising. Or if both, as is likely, to what degree and circumstance. Is it being strong, or is it side effects of processes that are involved in building and maintaining muscle mass the old fashioned way - e.g. hormetic effects of regular exercise, that cause mild cellular stress and thus boost housekeeping processes to better maintain tissue? Studies in shorter lived animals support causative roles for exercise and maintained muscle mass in long term health. For other data points, one could look at, for example, the fact that calorie restriction (not normally noted in conjunction with building strength) considerably reduces age-related loss of muscle mass and strength through a range of not fully understood mechanisms.

kyllo 14y ago
I think the calorie restriction studies deserve scrutiny. Do people who practice calorie restriction live longer compared to otherwise fit, healthy people who do not practice it? Or do they just live longer compared to the average (which includes a significant component of obese and/or diabetic over-eaters)?
- saalweachter 14y ago
  http://www.nature.com/news/calorie-restriction-falters-in-the-long-run-1.11297 http://www.nature.com/news/calorie-restriction-falters-in-th... This article actually answers both your questions: """ One reason for that difference could be that the WNPRC monkeys were fed an unhealthy diet, which made the calorie-restricted monkeys seem healthier by comparison simply because they ate less of it. The WNPRC monkeys’ diets contained 28.5% sucrose, compared with 3.9% sucrose at the NIA. Meanwhile, the NIA meals included fish oil and antioxidants, whereas the WNPRC meals did not. Rick Weindruch, a gerontologist at the WNPRC who led the study, admits: “Overall, our diet was probably not as healthy.” """ So, monkeys on a calorie restricted diet are not healthier than monkeys on a healthy, unrestricted diet, but are healthier than monkeys on a diet of monkey junk food.
- nnq 14y ago
  Indeed! If you actually had the time to look for studies correlating "calorie restriction without exercise" vs "exercise only" vs both with morbidity, please share a few links of what you've found.
- pekk 14y ago
  That's the question. Actually, it is not clear that calorie restriction increases human lifespans. It works really well with fruit flies and rodents, but monkey results are mixed. I don't know if there is any direct evidence of calorie restriction increasing lifespans in humans. Actually, practicing calorie restriction when young can affect development and practicing it when old might also be dangerous due to low BMI or bone loss. And if muscle is independently associated with mortality in men then losing muscle due to controlled starvation might not be helpful either.
- reasonattlm 14y ago
  Calorie restriction has a far better effect on human health for average, healthy people than any other presently available tool, technique, or medical technology. That's a definitive statement that can be made from results of the existing studies, such as those under the CALERIE program. http://calerie.dcri.duke.edu/ http://calerie.dcri.duke.edu/ E.g.: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2829643/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2829643/ There are no human longevity studies for the obvious reasons. The current consensus is that it won't add more than a few years to life. If it did reliably add to longevity to a significant degree, we'd already know about it for one, and secondly there are a range of evolutionary arguments for why CR produces larger effects on life span in shorter-lived species - since it evolved to adapt to famine (~= weather) conditions, which come and go on a fixed timescale depending on their cause, not one that is relative to species longevity. Reconciling tremendous proven health benefits versus little extension of life span is one of those interesting sidebars that will fall out of the scientific process at some point.
- Shorel 14y ago
  Don't forget carbohydrates restriction. Calories are not all the same.
Someone 14y ago
A scientific article with a funny title on this subject is "How fast does the Grim Reaper walk?" (http://www.bmj.com/content/343/bmj.d7679 http://www.bmj.com/content/343/bmj.d7679) In their study, no over 70 years old who had a walking speed of over 1.36 m/s (about 5 km/hour) died. That makes them conclude that that must be the grim reaper's top speed.

kyllo 14y ago

I think the calorie restriction studies deserve scrutiny. Do people who practice calorie restriction live longer compared to otherwise fit, healthy people who do not practice it? Or do they just live longer compared to the average (which includes a significant component of obese and/or diabetic over-eaters)?

saalweachter 14y ago
http://www.nature.com/news/calorie-restriction-falters-in-the-long-run-1.11297 http://www.nature.com/news/calorie-restriction-falters-in-th... This article actually answers both your questions: """ One reason for that difference could be that the WNPRC monkeys were fed an unhealthy diet, which made the calorie-restricted monkeys seem healthier by comparison simply because they ate less of it. The WNPRC monkeys’ diets contained 28.5% sucrose, compared with 3.9% sucrose at the NIA. Meanwhile, the NIA meals included fish oil and antioxidants, whereas the WNPRC meals did not. Rick Weindruch, a gerontologist at the WNPRC who led the study, admits: “Overall, our diet was probably not as healthy.” """ So, monkeys on a calorie restricted diet are not healthier than monkeys on a healthy, unrestricted diet, but are healthier than monkeys on a diet of monkey junk food.
nnq 14y ago
Indeed! If you actually had the time to look for studies correlating "calorie restriction without exercise" vs "exercise only" vs both with morbidity, please share a few links of what you've found.
pekk 14y ago
That's the question. Actually, it is not clear that calorie restriction increases human lifespans. It works really well with fruit flies and rodents, but monkey results are mixed. I don't know if there is any direct evidence of calorie restriction increasing lifespans in humans. Actually, practicing calorie restriction when young can affect development and practicing it when old might also be dangerous due to low BMI or bone loss. And if muscle is independently associated with mortality in men then losing muscle due to controlled starvation might not be helpful either.
reasonattlm 14y ago
Calorie restriction has a far better effect on human health for average, healthy people than any other presently available tool, technique, or medical technology. That's a definitive statement that can be made from results of the existing studies, such as those under the CALERIE program. http://calerie.dcri.duke.edu/ http://calerie.dcri.duke.edu/ E.g.: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2829643/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2829643/ There are no human longevity studies for the obvious reasons. The current consensus is that it won't add more than a few years to life. If it did reliably add to longevity to a significant degree, we'd already know about it for one, and secondly there are a range of evolutionary arguments for why CR produces larger effects on life span in shorter-lived species - since it evolved to adapt to famine (~= weather) conditions, which come and go on a fixed timescale depending on their cause, not one that is relative to species longevity. Reconciling tremendous proven health benefits versus little extension of life span is one of those interesting sidebars that will fall out of the scientific process at some point.
Shorel 14y ago
Don't forget carbohydrates restriction. Calories are not all the same.

Someone 14y ago

A scientific article with a funny title on this subject is "How fast does the Grim Reaper walk?" (http://www.bmj.com/content/343/bmj.d7679 http://www.bmj.com/content/343/bmj.d7679) In their study, no over 70 years old who had a walking speed of over 1.36 m/s (about 5 km/hour) died. That makes them conclude that that must be the grim reaper's top speed.