Every few years research on the effects of deuterium on life span in lower animals surfaces, by way of exposing them to heavy water, D2O rather than H2O. The presence of deuterium rather than hydrogen results in an uptake of deuterium atoms into biological molecules, subtly and slightly changing their behavior. Too much of that and you fall over dead - the mechanisms of life do not have a high tolerance for such tinkering, and heavy water is effectively toxic. At lower levels, however, species such as flies and nematodes live longer as a result of exposure to deuterium. A few articles and papers were published back in 2007-2009, which together give a fair grounding as to where the science stands:

• Eat Isotopes to Live Longer
• Deuterium Again
• SENS4, Session 1, Combating Oxidation

Dr Shchepinov's theory is based on deuterium, a naturally-occurring isotope, or form of hydrogen, that strengthens the bonds in between and around the body's cells, making them less vulnerable to attack. He found that water enriched with deuterium, which is twice as heavy as normal hydrogen, extends the lifespan of worms by 10 per cent. And fruitflies fed the 'water of life' lived up to 30 per cent longer.

There is some skepticism and debate amongst various parties regarding the mechanisms by which deuterium uptake extends life span, but it's clear that exposure to heavy water at lower levels does in fact extend life in flies, worms, and so forth. Not too many people are working on this, so there is a lot of room for speculation and a lack of hard evidence that can rule out possibilities such as increased resistance to oxidative damage in important proteins. Given the evidence backing the membrane pacemaker theory of longevity, this is an attractive idea - there is plenty of support for the hypothesis that differences in the proteins that make up cell membranes are responsible for large differences in life span between various otherwise similar species. But robust evidence for the much smaller difference of a little extra deuterium substituted for hydrogen atoms - as opposed to completely different proteins - is lacking.

On this topic, I see that a new paper has arrived in the prepublication queue at Rejuvenation Research. It adds more data to the current thin stack on deuterium and fly life span:

Brief Early-Life Non-specific Incoporation of Deuterium Extends Mean Lifespan in Drosophila melanogaster Without Affecting Fecundity

We have investigated the effects of brief, non-specific deuteration of Drosophila melanogaster by including varying percentages of 2H (D) in the H2O used in the food mix consumed during initial development. Up to 22.5% D2O in H2O was administered, with the result that a low percentage of D2O in the water increased mean lifespan, while the highest percentage used (22.5%) reduced lifespan. After the one-time treatment period, adult flies were maintained ad libitum with food of normal isotopic distribution.

At low deuterium levels, where lifespan extension was observed, there was no observed change in fecundity. Dead flies were assayed for deuterium incorporation ... Isoleucine and leucine residues showed a small, linear dose-dependent incorporation of deuterium at non-exchangeable sites. Although high levels of D2O itself are toxic for other reasons, higher levels of deuterium incorporation, which can be achieved without toxicity by strategies that avoid direct use of D2O, are clearly worth exploring.

Hormesis is a possible (and disappointingly ordinary) explanation for this sort of result. Given the range of ways to make flies, worms, and rodents live longer by exposing them to adversity in early life, this almost seems like the first place to be looking. Perhaps lesser degrees of heavy water exposure, entirely separately from any deuterium uptake into proteins, have a hormetic effect, causing enough damage and disarray to spur repair mechanisms into greater efforts and leading to a net gain in life expectancy.

Well, either way, we shall hear more in future years. As the researchers point out above, you can conduct similar studies without the need for heavy water, and those should produce a more useful set of data.

Source:
http://www.fightaging.org/archives/2013/01/deuterium-and-lifespan-in-flies.php

Recommendation and review posted by Fredricko

Exercise correlates with all sorts of better measures of health, but there is some debate and conflicting evidence on whether more is better past the point of moderate regular exercise. This ties in to questions of causation - to what degree are endurance athletes drawn to their activities because they are already more robust than their peers, for example?

Telomeres are the molecular caps on chromosomes. They shorten with each successive cell division and are thus linked to aging. The shortening rate also varies among people. Shorter telomeres have been linked to increased disease risk as well as shortening of lifespan.

Chronic endurance training is at least modestly linked with long lifespan, though there are some controversies about whether it may increase the risk of some heart diseases. In the current study researchers sought to determine if chronic endurance training is associated with telomere length in older aged individuals. To perform the trial they measured the length of telomeres in four groups of individuals: young people and older people who did or did non engage in chronic endurance training. For the endurance training the researchers chose participation in a 58 km cross country ski competition.

They found that indeed the older people who were chronic endurance trainers had significantly longer telomeres than moderately active older controls. There was no difference in telomere length in the younger subjects whether they did endurance training or not. There was also an association in older people between VO2 max and telomere length.

Link: http://extremelongevity.net/2013/01/10/chronic-endurance-training-linked-to-longer-telomeres-in-older-adults/

Source:
http://www.fightaging.org/archives/2013/01/endurance-training-associated-with-longer-telomeres.php

Recommendation and review posted by Fredricko

Over at In Search of Enlightenment you'll find an unpublished interview where the questions somewhat illustrate the point that most people don't look much beyond trivial matters when it comes to aging and longevity. Biotechnology like SENS and similar research projects are given no thought at all in most quarters, and even amongst advocates many favor the snail's pace path of trying to slow aging rather than working to repair its root causes to reverse it. This all means that there is much yet to accomplish in advocacy and education.

The field of research known as biogerontology, which studies the biology of aging, is a truly fascinating, though often misunderstood, area of scientific research. In 2011 the genome of the naked-mole rat was sequenced. This rodent is only the size of a mouse, and one might wonder what the significance of sequencing its genome could possibly be. But the naked-mole rate is the longest living rodent, it has a maximum lifespan exceeding 30 years and an exceptional resistance to cancer. Understanding the biology of this species could help unlock the mystery of healthy aging. A variety of experiments on fruit flies, mice and other species have demonstrated that the rate of aging can be manipulated, either by calorie restriction or by activating particular genes. Such research could eventually lead to the development of a drug that safely mimics the effects of caloric restriction (which delays the onset of disease) or actives the "longevity genes" that help protect against the diseases of late life.

The lion's share of funding for medical research is spent on disease research, such as research on cancer, heart disease or Alzheimer's disease. This approach, which I call "negative biology", assumes that the most important question to answer is "what causes disease?". Unfortunately this is a severely limited approach, especially for older populations. Even if you cured all 200+ forms of cancer (and we have not yet eliminated even just one cancer despite investing enormous sums of money for decades now), one of the other diseases of aging would quickly replace cancer as the leading cause of death because most people in late life are vulnerable to multiple diseases. So "positive biology" takes a different intellectual starting point. It assumes that the puzzles of exemplar health are just as important to understand as the development of disease. How can some (very rare) humans live over a century of disease-free life? Understanding these exemplar examples of health might prove to be more significant than trying to understand, treat and cure every specific disease of late life.

Link: http://colinfarrelly.blogspot.com/2012/12/readers-digest-interview-on-aging-and.html

Source:
http://www.fightaging.org/archives/2013/01/unpublished-readers-digest-interview-on-aging-and-longevity.php

Recommendation and review posted by Fredricko