There are any number of ways to make mice live a little longer by slowing the accumulation of cell and tissue damage that causes age-related degeneration. Processes such as the cellular repair mechanisms of autophagy, for example, influence life span, and anything that causes a little damage so as to provoke greater levels of repair tends to make shorter-lived species like mice live somewhat longer. Since all of the mechanisms of cellular metabolism influence one another directly or indirectly, there are countless ways to increase the level of cellular housekeeping. This is true of any of the other processes thought to influence life span in a similar way, but the value in this approach to aging is an open question. Life spans have evolved to be much more plastic in response to circumstances in short-lived animals; the same methods do not produce the same length of life extension when practiced by long-lived mammals such as we humans. Calorie restriction is perhaps the best example of this point. It can extend life in mice by up to 40% or so, but certainly isn't capable of that feat in our species.
Today I'll point out an open access paper in which the authors provide evidence to show that alkaline water intake at pH 8.5 over the long term very slightly slows aging in mice - it is a tiny effect. This is not a methodology I had heard of, though there are a few papers out there on the intermittent use of alkaline water as a treatment for conditions in which the stomach produces too much acid, as well as exploring the effects of long-term alkaline water intake on rats at pH 11 to 12. A year of water at that alkalinity led to rats that were smaller and less healthy for reasons that remain unclear; the researchers concluded that "long-term exposure to alkaline drinking water seems to have profound systemic effects manifested as significant growth retardation, as a result of mechanisms that require further studies." However, there are other studies suggesting beneficial effects of various sorts, perhaps through a positive impact on levels of oxidative stress or fundamental cell mechanisms relating to growth. There is also, it seems, a thriving snake oil community happy to tell you that drinking alkaline water or eating a more alkaline diet will cure all ills.
It seems a fair wager that life is extended very slightly in mice via long-term alkaline water intake through hormesis. The alkalinity causes a little damage that produces increased cellular maintenance activity for a net benefit. The rats were exposed to greater alkalinity, so these results may well be points on the standard dose-response curve for a damaging substance. Alternatively, since the authors don't seem to have controlled for calorie intake, and alkaline water is claimed by some authors to negatively impact the apparatus of digestion, the result may also be a consequence of mild calorie restriction. There is enough uncertainty to propose other possible mechanisms, but to my eyes this is an excellent example of research that is interesting to pick apart while being no real value to our community.
Alkaline Water and Longevity: A Murine Study
The biological effect of alkaline water consumption is object of controversy. Alkaline and electrolyzed water have been shown to exert a suppressive effect on free radical levels in living organisms, thereby resulting in disease prevention. Various biological effects, such as antidiabetic and antioxidant actions, DNA protecting effects, and growth-stimulation activities, were documented. Although a variety of bioactive functions have been reported, the effect of alkaline water on lifespan and longevity in vivo is still unknown. Animal alkalization has been shown to be well tolerated and to increase tumor response to metronomic chemotherapy as well the quality of life in pets with advanced cancer. Therefore, we performed a study based on survival rate experiments, which play central role in aging research and are generally performed to evaluate whether specific interventions may alter the aging process and lifespan in animal models. The present paper presents a 3-year survival study on a population of 150 mice, and the data were analyzed with accelerated failure time (AFT) model.
The experiment consisted in an initial 15-day acclimatization period. After acclimatization, animals (50, group A) were watered with alkaline water at pH 8.5, obtained by a water ionizer, whereas group B animals (50) were watered with water alkalized at pH 8.5 by a concentrated alkaline solution for 15 days. Group C animals (50), control group, were watered with the local water supply at pH 6-6.5. This period has been identified to gradually accustom the animals treated with alkaline water. At the end of the second period of acclimatization, group A and B animals were watered with alkaline water at pH 9.5, while animals of group C were watered with local tap water. After the first year, the most aggressive individuals were moved to other cages within the same group and an environmental enrichment protocol was employed in order to decrease the hyperactivity. This phenomenon was observed especially in animals of groups A and B.
The results provide an informative and quantitative summary of survival data as a function of watering with alkaline water on long-lived mouse models. Starting from the second year of life, mice watered with alkaline water showed a better survival than control mice. Histological examination of mice kidneys, intestines, hearts, livers, and brains was performed in order to verify the risk of diseases correlated to alkaline watering. No significant differences emerged among the three groups. No significant damage, but aging changes, emerged; organs of alkaline watered animals resulted to be quite superimposable to controls, shedding a further light in the debate on alkaline water consumption in humans.
View the full article at FightAging
