One common argument against indefinite lifespans is that a definitive limit to one’s life – that is, death – provides some essential baseline reference, and that it is only in contrast to this limiting factor that life has any meaning at all. In this article I refute the argument’s underlying premises, and then argue that even if such premises were taken as true, its conclusion – that eradicating death would negate the “limiting factor” that legitimizes life – is also invalid, because the ever-changing state of self and of world can constitute such a limiting factor just as well as death can, which can be seen lucidly in the simple fact that opportunities once here are now gone, and that it is not death but life itself that is responsible for that.
Aging destroys fitness. How could aging have evolved? This is my answer to this question. This is mainstream science from peer-reviewed journals, but it is my science, and as Richard Feynman warned us, I’m the last one who can be objective about the merits of this theory.
I’ve been at the annual meeting of the American Aging Association this past weekend. Here are some brief take-home messages from the presentations I’ve attended.
Eating less helps you live longer, but eating less is hard. One line of experiment suggests that eating less of just one protein component, methionine, is sufficient to extend life span, perhaps as effectively as though less calories were being consumed. It’s an intriguing idea, though the research is fraught with contradictions, and to separate methionine from other protein components is not easy or cheap.
The immune system of older people declines in reliability and efficiency with age, resulting in greater susceptibility to pathology as a consequence of inflammation, for example, cardiovascular disease, Alzheimer’s disease, autoreactivity and vaccine failure, as well as an increased vulnerability to infectious disease.
A new report this week about signals from hypothalamus reminds us that some of the biggest influences on longevity are mediated through the nervous system. To this extent, the decision about how long to live comes from a calculation made in the brain. The new research suggests a hormone known as GnRH as a relatively simple signal by which aging might be slowed, and another signal called NF-kappa-B promotes aging and might be blocked to slow aging.
Eating less is the best-tested and surest way to a younger body and an increased life span. But it’s a hard discipline to maintain, and many of us would welcome an easier alternative. Perhaps we can realize some of the benefits applying a more temporary exercise of willpower, with intermittent fasting. It’s counter-intuitive, but seems to be true, that health and longevity are better served by clumping up our food consumption (feast and famine) than by spreading food consumption evenly through the day and through the week.
“The way evolution works makes it impossible for us to possess genes that are specifically designed to cause physiological decline with age or to control how long we live.”
Darwin’s legacy, his gift to science is the idea of a creative competition that selects the strong, the robust, the fertile, and thereby ratchets the complexity of life.