We are living longer today than ever. The average life expectancy for an American hit a record high last fall, 78.8 years; other countries are seeing similar increases in longevity.
This is great news, but it also means we are living in increased fear of the decline that often accompanies old age. For most people, that fear is sharpest on the subject of mental decline.
The fear is understandable, especially since the possibility is not as remote as most of us would wish. Alzheimer’s disease, the most common cause of irreversible dementia in people 65 and older, affects an estimated 5 million Americans. The Alzheimer’s Association predicts that the number could triple by 2050.
But several new drug therapies have offered hope that there may be treatments on the way that can halt or even reverse Alzheimer’s disease. The biotechnology company Biogen made headlines recently with the announcement that its newest experimental drug performed better than expected in early studies. The medicine showed a statistically significant effect in slowing cognitive decline and reducing amyloid plaque, protein deposits in the brain that are thought to be one of the disease’s major causes. Tau protein, another factor which researchers at the Mayo Clinic recently suggested may be even more critical, is the target for several medications in development by Biogen and other companies.
These recent drugs are not the only signs of progress. A few years ago, a biomedical engineer and neuroscientist at the University of Southern California in Los Angeles demonstrated some success with experiments in the use of neural prostheses - silicon chips designed to mimic a neuron’s ability to process brain signals. The idea is to eventually restore the ability to create new memories in those who have lost it due to degeneration or trauma. Some Alzheimer’s researchers are also shifting the focus of their research to the ApoE protein, which serves an unknown function in the brain but is strongly tied to the risk of early-onset Alzheimer’s. Gene therapy may also offer great promise in combatting the disease, as I discussed in this space earlier this week. While a cure for, or even a full understanding of, Alzheimer’s has not yet arrived, these developments offer strong hope that it’s a matter of when, not if, it will.
But even a world completely free of Alzheimer’s would not be a perfect world for those who live to and beyond our ever-extending life expectancies. Other conditions can also cause dementia, including Parkinson’s disease and vascular dementia, neither of which are currently reversible. Older adults are also at risk for developing clinical depression, which can go undiagnosed and may be aggravated by isolation and loneliness.
There are other, physical ailments that can ultimately prevent most people who attain extreme old age from living independently, even if they are lucky enough to avoid mental decline of any sort. Older adults often lose mobility and dexterity, which makes daily activities difficult; they may also experience reduced vision, hearing or both. Walking, cooking, seeing to personal hygiene and housework can all become too much to handle - and this is after giving up the car keys, voluntarily or otherwise. Accidents, especially falls, become a greater risk and can abruptly curtail independence.
Therapies to halt cognitive decline will be a great boon to aging populations, but they won’t be the sole solution to living through our ninth or tenth decades. We are going to need a lot more care, especially affordable in-home care, since by far the most comfortable and economically efficient solution to the needs that arise in extended life is to stay in one’s familiar surroundings. We should also have plans in place with our loved ones well before reduced mental or physical capacity becomes a problem. And we will need social outlets, too, to ensure that we do not find ourselves cut off from the wider world as we live our final years. Some of these are problems to tackle as individuals, but many of them we will have to address together as a society.
We know a lot about how to live longer, and we are learning more all the time. Now we need ways to live those extra years better. Medical science will deliver part of the answer; social science will have to provide the rest.