October 24, 2010

Why life extensionists need to be concerned about neurological diseases

I'm having a hard time getting excited these days about apparent advances in longevity medicine. Don't get me wrong, many of these breakthroughs are truly fantastic, such as a potential pill to mimic the effects of caloric restriction, or the ability to reverse aging of human muscle tissue. What troubles me, however, is that many of these advances don't address the single most important aging related problem we face today: neurological diseases. Until we can meaningfully treat age-related cognitive decline, many of these other life extending advances are a moot point; what we're in danger of doing right now is extending lifespan, but not necessarily healthy life span.

The human brain degrades quickly with advanced age and, as a result, represents the weakest link in the life extension chain; as far as I'm concerned it's full stop until we can meaningfully fix the cognitive problems associated with aging.

Yes, age-associated diseases such as cancer and cardiovascular disease are clearly bad, but the most devastating of these involve the nervous system—diseases like Alzheimer's and Parkinson's. These diseases take a brutal toll on individuals and their families, often virtually killing the person well before they die.

That we are facing a looming epidemic of neurological diseases shouldn't really come as a surprise to anyone. But what is surprising is that very few people are actively doing anything about it. And it's not that the writing isn't on the wall—it is. The time to act is now.

The problem

In 40 years a significant proportion of the world population will be 65 and over, a combination of surviving Baby Boomers and Generation X'ers. Collectively, this demographic might outnumber the remaining population, meaning that elderly persons will make up the majority. That's rather astounding when you think about it, not to mention precedent setting.

The reasons for this trend are well documented. Average lifespan has more than doubled since 1840 and is steadily increasing at a rate of five hours every day. We are healthier, safer and more vibrant over the course of our lives than ever before—a factor that is leading to increased longevity. And not only are we staying physically healthier for longer periods, we are also remaining mentally sharper into our eldery years; a recent study showed that 70-year-olds are smarter than they used to be.

But the double-edged sword that is extended life is not without its limits.

The chances of acquiring a neurological disease like Alzheimer's increases exponentially after the age of 65, and it is estimated that within the next 50 years approximately 30% of the population will be aged 65 years or older. Of those between 75 and 84 years of age, 6 million will exhibit some form of Alzheimer's symptoms, and of those older than 85 years, over 12 million will have some form of dementia associated with it. Disturbingly, many cognitive changes occur even in the absence of specific age-related neurodegenerative diseases. Common components thought to contribute to the manifestation of these disorders and normal age-related declines in brain performance are increased susceptibility to long-term effects of oxidative stress and inflammatory insults. Should we fail to reduce these age-related decrements in neuronal function, health care costs will continue to rise exponentially, as will the amount of human suffering.


There is currently no cure or (meaningful) prevention for most of these diseases. At least not yet.

Age-associated cognitive decline is currently costing the healthcare system a third of a trillion dollars per year. It is estimated that by 2050 this figure will exceed a trillion. As it stands, the largest benefactors to these lines of research are philanthropies. Governments, on the other hand, have largely ignored the issue. This has obviously got to change.

In terms of research, there are a number of teams tackling this problem from different angles, including Gregory Petsko, professor of biochemistry and chemistry at Oxford University. He is working to untangle misfolded proteins responsible for neurological decline. He is trying to develop a kind of "molecular scotch tape" to help proteins keep their shape and prevent tangles.

It's these tangles of misfolded proteins that Petsko believes is responsible for not just Alzheimer's, but possibly all age-associated cognitive decline. If true, then finding a treatment for any of them should help in treating all of them.

Other possible approaches include the use of phytochemicals to improve age-related neurological dysfunction, or, in the case of Parkinson's, coaxing dormant neurons to take on the dopamine-producing role of damaged neurons and to restore the brain's control of movement. There are obviously many more approaches, and there's no telling which line of inquiry will prove to be the most effective, but it's early days. The prevention and curing of cognitive decline will likely involve a host of treatments as it's likely caused by a multiplicity of factors.

Solutions for today

In the meantime there are things you can do today. For Parkinson's prevention, be sure to ingest caffeine and avoid head injuries. For those at risk of Alzheimer's, be sure to eat lots of fish oil, keep your blood pressure down (as it appears to be the single most important risk factor), and keep yourself mentally stimulated (use it or lose it, as they say).

And lastly, do what you can to either fund or promote research that works to reduce or eliminate the effects of age-associated neurological diseases. Your future mental health will likely depend on it.


Mark Plus said...

Apparently college education helps to build up a cognitive reserve which postpones the effects of Alzheimer's. I find it interesting that at the same time we now see efforts, for example Peter Thiel's, to discourage so many people from going to college. Which costs more over the long run for an 18 year old: a college education now, or an earlier onset of Alzehimer's in a few decades?

Ben Goertzel said...

Yes, this is right on target.

In my work with Genescient on long-lived flies, I am finding many neuro-related genes to be highly significant in explaining the flies' longevity... [tentative, preliminary results -- but sure interesting...]

ZarPaulus said...

Yes, considering that the neurons in the brain are some of the few cells that never replace themselves (well, a few do the the vast majority don't, and you lose whatever memories were associated with the replaced neuron).