Wednesday, November 12, 2008

Ten Things You Probably Didn’t Know (But Should) About Aging

Why, you might wonder, would a philosopher and political theorist spend so much time worrying about aging (see here, here and here)?

Well, because I believe aging is the most important neglected issue of our time! If you don't believe me, consider the following ten facts about aging you probably didn't know:

1. The inborn aging process is now the major risk factor for disease and death after around age 28 in the developed countries and limits average life expectancy at birth to approximately 85 years (source).

2. Why do we age? Aging occurs because natural selection favors a strategy in which organisms invest fewer resources in the maintenance of somatic cells and tissues that are necessary for indefinite survival of the individual. (source)

3. Aging is not immutable. The lifespan of organisms such as worms, flies, and mice can be extended by restricting food intake. And experiments with the fruit fly Drosophila melanogaster have demonstrated that their lifespan can be doubled by delaying reproduction over generations. (source) Castration of salmon (source) and humans (source) can also extend lifespan.

4. Approximately 1 in 10 000 Americans are centenarians (source). Having a centenarian sibling increases one’s chances of survival to very old age. (source). The FOXO3A genotype is strongly associated with human longevity (source).

5. The first human clinical trials for an anti-aging molecule began this year. (sources here and here)

6. If you live to 95, you actually stop aging! (but have a very high risk of mortality) (source)

7. In the two hundred years from 1800 - 2000, life expectancy at birth in the world increased from below 30 to 67. (source).

8. There are approximately 600 million persons aged 60 years and over; this total will double by 2025 and will reach virtually two billion by 2050 - the vast majority of them in the developing world. (source) October 1st is the International Day of Older Persons.

9. Despite the fact that the vast majority of the world's 6.5+ population will die from age-related causes, aging research is underfunded. In the year 2006, the National Institutes of Health was funded at $28 billion and yet less than 0.1% of that funding was spent on understanding the biology of aging. (source)

10. Even a modest deceleration in human aging could be this century’s most important medical intervention. Furthermore, there is a sound scientific basis for believing this could be achieved. We are closer to this goal than we are to eliminating cancer or heart disease. Furthermore, age retardation could yield health dividends far greater than those that would be achieved by the elimination of any specific disease of aging. This is the case because of the fact of co-morbidity. This means that eliminating all cancers would only add a few years to life expectancy as one of the other afflictions of senescence would soon ravage an aged person (e.g. heart disease, stroke, diabetes, AD, etc.). So delaying all these afflictions is much more important than eliminating just a couple of them.