For those of us now entering middle age, it's early days in the new school fight against aging. If we stay in good health, we have a good 50 years of science in which to find a way to cure and reverse the effects of aging. My personal sense of things is that this is probably just about enough time to be sure of achieving this goal. Most great ideas are brought into existence about 50 years after people stop considering it ridiculous. This is as much an educated guess as anything else, however, and all the signs also point to major gains in the healthy human lifespan within 20 years due to regenerative medicine. The ability to repair the damage of aging will give us more time in which to understand how to prevent it.
Despite this 50 year buffer, I am very glad to see major initiatives underway aimed at understanding the genetics and biochemistry of the brain. The brain really is in a class of its own in terms of the technology we need to ensure long term healthy life extension. Unlike everything else we only have one of, you can't just whip out the brain and replace it with a new one. Even today, we have sophisticated techniques to replace or repair the heart and keep the patient alive during the process - but our self, our mind, does not reside in the heart.
Scientists in the tissue engineering and regenerative medicine fields sound confident that, over the next ten or twenty years, we learn how to grow new organs on demand from the stem cells of any given patient. It's an enormously complicated problem, but the path to solving it is very clear. Transplant grown from your own cells open up a while field of options to extend life span and cure disease by replacing any failing part of the body ... except for the brain. Medical researchers need to develop a different toolbox in this case. We can't skip over understanding exactly how the human brain works, as we will have to develop medical technologies that can repair age-related and disease-related damage in situ - all without disrupting or damaging the mind that resides in the brain being treated.
You can see the earliest goals in this process being achieved in the fight against Alzheimer's, a horrible condition that cannot be cured too quickly for my liking. Individual mechanisms of aging and operation in the brain that relate to this condition are now being picked out and used to develop therapies. (This of course is the result of a enormous increase in funding for Alzheimer's research over the past decade - nothing like this sort of progress happens in the absence of funding). Alzheimer's is particularly worrisome from a healthy life extension perspective because it appears to be an inevitable part of the aging process. Some people get it later than others, but live long enough and you will get it, and it will kill you. First, however, it will destroy your mind; a shuddersome fate.
I expect to see advancing neuroscience - scientists in this field have already made amazing process in understanding the way in which mind, memory and thought relate to physical structures inside the brain - merge at the boundary with regenerative medicine. Understanding exactly how the brain works naturally leads to understand how to repair it when it becomes damaged. If you are interesting in learning more about where neuroscience is today (and what the implications are for the future) a good starting point is the Brain Waves blog.