Tuesday, November 30, 2010

Vitamin D (update)

Today's Globe has this story about a new report on the recommended daily levels of vitamin D. The story is premised on this report published today by the Institute of Medicine of the National Academies.

The Institute's report, which was undertaken at the request of the US and Canadian governments, looked at both calcium and vitamin D. As I have noted in my previous posts on vitamin D, it is interesting to follow how things develop with this vitamin as an anti-aging intervention (that perhaps mimics the effects of CR) would likely face similar challenges.

The first challenge: figuring out what constitutes a safe and effective dose.

There are dangers with being too bold and with being too cautious. Prescribing people to take very high doses of a chemical (even a "natural" one) could be harmful. And yet prescribing people take a very low dose could also be harmful in that it won't realize the health benefits of a higher dose. How do we reasonably balance these different possible harms and benefits?

These concerns are what we see in this report on vitamin D. The recommended dietary allowance of vitamin D has been raised to 600 IU/day. This triples the recommended levels. Health Canada had prescribed that 200 IU/day were recommended, and that this level could be reached by simply drinking two cups of milk a day. But the new, higher levels will mean some people should take a daily supplement.

In addition to revising recommended daily dosage of vitamin D, this report has also increased the upper intake level from 2000 IU to 4000 IU. The purported benefits (lower rates of internal cancers) of taking higher doses of vitamin D is, at this stage, inconclusive. This presents a second challenge: what to do when the findings are still inconclusive?

Daily dosages of vitamin D between 600 IU and 4000IU are still an "unknown" in terms of health benefits. These levels have been deemed safe, but does a dosage above 600 IU confer any health benefit? And what is it reasonable to do when such uncertainty exists? Should one take a higher dose, a dose that is deemed safe, just in case it has benefits? Or should one wait to see if conclusive evidence emerges about the alleged health benefits before increasing one's dosage? It's a tricky dilemma. I have my own views on this issue, but I'll leave it up to readers to make their own decisions about what levels of vitamin D they should take.

Now that the vitamin D max dosage has been increased, more studies on their purported health benefits will take place. So it will be interesting to see how things unfold in the years to come.


Monday, November 29, 2010

Nature Study on Reversing Aging in Aged Telomerase-Deficient Mice

This study published as an advance online publication in Nature could prove very important for the health prospects of an aging world. It opens up the prospect of reversing, and not merely slowing, aging. Granted the study was done on abnormal (telomerase-deficient) mice, which means it is not as exciting as an intervention that reversed aging in normal mice. But it is, nonetheless, an important step forward in the science of aging.

The Harvard Gazette as the scoop here. And here is an excerpt from the publication:

An ageing world population has fuelled interest in regenerative remedies that may stem declining organ function and maintain fitness. Unanswered is whether elimination of intrinsic instigators driving age-associated degeneration can reverse, as opposed to simply arrest, various afflictions of the aged. Such instigators include progressively damaged genomes. Telomerase-deficient mice have served as a model system to study the adverse cellular and organismal consequences of wide-spread endogenous DNA damage signalling activation in vivo1. Telomere loss and uncapping provokes progressive tissue atrophy, stem cell depletion, organ system failure and impaired tissue injury responses1. Here, we sought to determine whether entrenched multi-system degeneration in adult mice with severe telomere dysfunction can be halted or possibly reversed by reactivation of endogenous telomerase activity. To this end, we engineered a knock-in allele encoding a 4-hydroxytamoxifen (4-OHT)-inducible telomerase reverse transcriptase-oestrogen receptor (TERT-ER) under transcriptional control of the endogenous TERT promoter. Homozygous TERT-ER mice have short dysfunctional telomeres and sustain increased DNA damage signalling and classical degenerative phenotypes upon successive generational matings and advancing age. Telomerase reactivation in such late generation TERT-ER mice extends telomeres, reduces DNA damage signalling and associated cellular checkpoint responses, allows resumption of proliferation in quiescent cultures, and eliminates degenerative phenotypes across multiple organs including testes, spleens and intestines. Notably, somatic telomerase reactivation reversed neurodegeneration with restoration of proliferating Sox2+ neural progenitors, Dcx+ newborn neurons, and Olig2+ oligodendrocyte populations. Consistent with the integral role of subventricular zone neural progenitors in generation and maintenance of olfactory bulb interneurons2, this wave of telomerase-dependent neurogenesis resulted in alleviation of hyposmia and recovery of innate olfactory avoidance responses. Accumulating evidence implicating telomere damage as a driver of age-associated organ decline and disease risk1, 3 and the marked reversal of systemic degenerative phenotypes in adult mice observed here support the development of regenerative strategies designed to restore telomere integrity.


Thursday, November 18, 2010

Virtue Epistemology and Democracy (Part 2)

This post continues the ideas and themes outlined in this previous post.

Recall that virtue epistemology makes intellectual agents and communities the primary source of epistemic value and the primary focus of epistemic evaluation. Construing knowledge as "success from ability or virtue" thus provides the political theorist with an interesting way of approaching the topic of the epistemic virtues/vices of democracy. So one of the first issues to consider is: what is democracy?

The Condorcet Jury Theorem [1785], which is the most influential epistemic account of democracy, conceives of democracy as a system of majoritarian rule and it considers the action of voting as the primary political activity. Anderson succinctly summarizes the Condorcet Jury Theorem:

This theorem states that if voters (a) face two options, (b) vote independently of one another, (c) vote their judgment of what the right solution to the problem should be (i.e., they do not vote strategically), and (d) have, on average, a greater than 50% probability of being right, then, as the number of voters approaches infinity, the probability that the majority vote will yield the right answer approaches 1 (and rapidly approaches 1 even with modest numbers of voters). (Source)

The Condorcet Jury Theorem, with its fixation on voting and majority rule, does not provide us with a compelling basis on which to defend the epistemic virtues of democracy. Firstly, voters seldom face just two options. In a representative democracy voters typically vote for representatives (and only very seldom on referendum-style issues, and even then the choice might be greater than two). For countries that have more than two major political parties, this plurality of choices contravenes the artificial constraints of the Condorcet Jury Theorem.

Furthermore, even when two major political parties do dominate the political landscape the final options available to voters are themselves at least partly shaped and influenced by the democratic process itself. For example, in the case of a Presidential election, Democratic and Republican nominees must first win the support of their respective political parties before making it on the final Presidential ticket. And the policies and principles that nominees decide to run on will already be shaped in light of what the candidates believe reflect the priorities and concerns of their constituents. In other words, voters are not just given two options to vote between. Rather, the input of voters and party members (at least partly) determines what the available menu of options are to begin with. So actual democratic processes are much more complex and nuanced than the limited options presumed in the Condorcet Jury Theorem.

It is thus a mistake to make, as the Condorcet Jury Theorem does, the activity of placing one’s solitary vote the central focus of an assessment of the epistemic fitness of democracy. The Condorcet Jury Theorem treats democratic decision-making in a binary, synchronic fashion, as if the decision the citizenry makes at time T1 could be labelled as “the correct” or “the wrong” decision despite the fact that the circumstances facing the citizenry might alter significantly over time.

I believe virtue epistemology offers democratic theorists a novel way to broach the topic of the epistemic capacity of democracy without appealing to the impoverished and artificial assumptions of the Condorcet Jury Theorem. By making intellectual agents and communities the primary source of epistemic value and focus of epistemic evaluation, deliberative democrats are better positioned to bring to the fore the distinctive epistemic features of deliberative democracy.

Unlike the aggregative model of democracy, which conceives of the democratic process as a simple “show of hands” mechanism for aggregating individual preferences, deliberative democrats emphasis how participation in the democratic process is a transformative process. “Through the process of public discussion with a plurality of differently opinioned and situated others, people often gain new information, learn of different experiences of their collective problems, or find that their own initial opinions are founded on prejudice or ignorance, or that they have misunderstood the relation of their own interests to others” (Young 2000, 26).

Because democracy entails openness, inclusion, equality, accountability, etc., it fosters the habits of mind essential to wise decision-making; namely, the intellectual (as well as moral) virtues. Democratic decision-making can help guard against the dangers of prevalent cognitive limitations and biases because it helps facilitate the psychological continuity and connectedness necessary to overcome the availability heuristic, group polarization and prospection errors. By having many people “conversationally present” in central deliberative institutions (like Congress), as well as “imaginatively present” (Goodin, 2005) in our minds, the democratic polity puts itself in the favourable position of meeting the challenges of an unpredictable and often hostile world. Chance favours the open and connected mind.

Assessing the merits and demerits of redressing different kinds of risks to human flourishing, in the open and transparent forum of a political debate, for example, can help populations respond (in a more rational manner) to different harms and risks. Of course the political process might also exacerbate this problem, if politicians seeking election simply play on the irrational fears of the population vulnerable to the availability heuristic. So there is no guarantee that democratic outcomes will always lead to rational or reasonable outcomes. Much depends on the quality of the media in a democratic culture, the democratic education provided to the citizenry, etc. But the culture of democracy is one that helps perpetuate and cultivate the habits of mind necessary for intellectual virtue. And key aspects of democratic decision-making help guard against intellectual vice.

Firstly, democratic decisions are provisional. So even though irrational emotional responses might rule the day when deciding to implement X at time T1, this does not prevent society from reversing X at time T2, when cooler heads have had the time and opportunity to prevail. Furthermore, democratic decision-making is a forum for contestation, and thus the critics of X will do their best to reveal why policy X was unwise. If the case is compelling enough, then the earlier decision might be reversed. Thus a healthy democratic polity will promote the intellectual virtues of diligence and thoroughness, as well as the “detective’s virtues”. The decisions of political elites in a democracy (unlike an epistocracy) are not insulated from criticism from rival political parties, the free press, individual citizens, etc. Indeed, being open-minded, respectful of dissent, and questioning the reliability of one’s factual claims are an intricate part of democratic culture and institutions. They are the “democratic-method” for achieving phronesis.

In Democracy and Education John Dewey describes science as:

...that knowledge which is the outcome of methods of observation, reflection, and testing which are deliberately adopted to secure a settled, assured subject matter. It involves an intelligent and persistent endeavour to revise current beliefs so as to weed out what is erroneous, to add to their accuracy, and, above all, to give them such shape that the dependencies of the various facts upon one another may be as obvious as possible. (1916, 256)

Dewey goes on to say that “science marks the emancipation of mind from devotion to customary practices and makes possible the systematic pursuit of new ends. It is agency in progress” (1916, 261). Is there a parallel to be made between science and democracy? Would it be accurate to describe democracy itself as “emancipation from devotion to customary practices” and “agency in progress”? Dewey believed there was. In The Public and Its Problems he argued that the essential need is “the improvement of the methods and conditions of debate, discussion and persuasion” (1927, 208). And this improvement, he continued, “depends essentially upon freeing and perfecting the processes of inquiry and of dissemination of their conclusions”. Dewey believed that democracy was connected with the growth of the experimental method in the sciences, evolutionary ideas in the biological sciences, and the industrial re-organization (Dewey 1916, 5).

It is important to emphasize that, for Dewey, democracy was more than a form of government. It was the “name for a life of free and enriching communion” (1927, 184). And it is this "life of free and enriching communion" that ought, I believe, to be the focus on an epistemic evaluation of democracy.


Tuesday, November 16, 2010

Hypatia Paper Published on Early View

My paper entitled "Patriarchy and Historical Materialism" is now available on the early view articles for the feminist journal Hypatia.

Here is the abstract of the paper:

Why does the world have the pattern of patriarchy it currently possesses? And why do patriarchal practices and institutions evolve and modify the way they have tended to over time in human societies? This paper explores these general questions by integrating a feminist analysis of patriarchy with the central insights of the functionalist interpretation of historical materialism advanced by G.A. Cohen (1978, 1988). The paper has two central aspirations. Firstly, to help narrow the divide between Analytical Marxism and feminism by redressing the former’s neglect of the important role female labor has played, and continues to play, in shaping human history. Secondly, by developing the functionalist account of historical materialism to take patriarchy seriously, useful insights for diagnosing the emancipatory challenges that women face in the world today can be derived. The degree and form of patriarchy present in any particular society is determined by the productive forces it has had at its disposal. According to historical materialism, technological, material and medical advances that ease the pressures on high fertility rates (such as the sanitation revolution, vaccinations, birth control, etc.) are the real driving force behind the positive modulations to patriarchy witnessed in the twentieth century.

The argument I develop integrates Cohen's functionalist account of historical materialism with Gerda Lerner's account of the history of patriarchy.

Here is a brief summary of my central arguments:

(1) basic materialism: Humans have basic needs, the fulfillment of which is a precondition for any other form of life (e.g., social, political or intellectual life). To meet our basic needs humans had to labour. And the precarious situation of early hunter-gatherer societies meant that a priority had to be given to two important, and interdependent, kinds of labor: (a) warfare labor-- protecting one’s tribe from invasion by other tribes, as well as invading others when need be; and (b) reproductive and caring labor- the labor necessary to create and raise offspring. A group highly vulnerable to either predation or low birth rates would not survive long in the external conditions typical of the Late Pleistocene and early Holocene. This early division of male and female human labor thus set the foundation for the class relations that arise in slave, feudal and capitalist societies. For these are the relations of production of patriarchy. Relations that are further shaped, molded and reinforced by the legal and political institutions that arise in early states.

(b) synchronic materialism:
The subordination of women becomes formalized, and intensified, by the creation of superstructures that help stabilize these oppressive relations of production. Such relations give men effective control over the reproductive and caring labor of women. These patriarchal superstructures begin in slave societies, but continue through feudalism and capitalism.

(c) diachronic materialism: the productive forces of capitalism permit the modification of the worst forms of patriarchy. Once the pressures on maintaining high levels of fertility subside, due to declines in infant, maternal, and mid-life mortality, a greater portion of female labor can (and must be) utilized outside the home. Working outside the home permits women to make important impacts on the superstructure of society, thus resulting in greater political inclusion and equality. Diachronic materialism maintains that the degree and form of patriarchy in a society is determined by the productive forces it has at its disposal.

The ideas for this paper can be traced back to some thoughts first outlined on this blog over two years ago (see here and here).


Sunday, November 14, 2010

Editorial on Uniting Biogerontologists and Geriatricians

The latest issue of The Journals of Gerontology has this interesting editorial on uniting biogerontologists and academic geriatricians. The abstract:

Biogerontologists and academic geriatricians are both dedicated to promoting a healthier longevity for our society from their perspectives of scientific research on aging and education as part of clinical care for older persons. Yet at the present time, the prospects for translating research advances made by the biogerontologists to improve the outlook for health care provided by the geriatricians are limited by a “gulf” that exists between them, with little shared dialogue or scientific interchange. This article sets forth a basis for a union between both disciplines to prepare for the potential application of basic aging research to the provision of health care, with the aim ultimately to extend “health span” during our life span.


Saturday, November 13, 2010

3 Wishes

Tuesday, November 09, 2010

Moral Excellence and Leadership in the Workplace

The latest issue of the Journal of Positive Psychology has this study on a leader's ability to elicit elevation (a reaction to moral excellence).

Here is the abstract:

Leaders influence followers in many ways; one way is by eliciting positive emotions. In three studies we demonstrate that the nearly unstudied moral emotion of 'elevation' (a reaction to moral excellence) mediates the relations between leaders' and their followers' ethical behavior. Study 1 used scenarios manipulated experimentally; study 2 examined employees' emotional responses to their leaders in a natural work setting; study 3 compared the effects of elevation to those of happiness, serenity, and positive affect. We found that leaders' interpersonal fairness and self-sacrifice are powerful elicitors of elevation, and that this emotion fully mediates leaders' influence on followers' organizational citizenship behavior and affective organizational commitment. In the first study, we also observed a moderation effect of interpersonal fairness on self-sacrifice. Results underline the importance of positive moral emotions in organizations and shed light on the emotional process by which ethical leaders can foster positive organizational outcomes.


Tuesday, November 02, 2010

STM Commentary on Late-Life Interventions in Aging

The August issue of Science Translational Medicine has this interesting commentary on the importance of trying to preempt a global aging crisis. Here is the abstract:

The social and medical costs of the biological aging process are high and will rise rapidly in coming decades, creating an enormous challenge to societies worldwide. In recent decades, researchers have expanded their understanding of the underlying deleterious structural and physiological changes (aging damage) that underlie the progressive functional impairments, declining health, and rising mortality of aging humans and other organisms and have been able to intervene in the process in model organisms, even late in life. To preempt a global aging crisis, we advocate an ambitious global initiative to translate these findings into interventions for aging humans, using three complementary approaches to retard, arrest, and even reverse aging damage, extending and even restoring the period of youthful health and functionality of older people.