As More People Live Longer Why Are Rates of Dementia Falling? Theodore Dalrymple
The New England Journal of Medicine: “in 1993, 12.2% of surveyed adults 70 years of age or older [in America] had cognitive impairment, as compared with 8.7% in 2002.”
One of our present concerns in the western world is the rapid aging of the population. Never have so many people lived to so ripe an old age, and this at a time when the birth rate is falling. Who is going to support the doddering old fools who will soon be more numerous than the energetic and productive young?
A recent article in the New England Journal of Medicine points out that something unexpected has happened to confound the gloomy prognostications of epidemiologists and demographers. As the percentage of people surviving into old age increases, so the proportion of them who suffer from dementia decreases. People are not only living longer, but living better. This is a phenomenon that has happened across the western world.
The explanation favored by the authors is first that the general level of education of the population has increased and second that the prevalence of risk factors for the development of small blood vessel disease, which causes dementia, has declined. Old people have healthier lifestyles and do more exercise than they used to. The decline in smoking (oddly enough once thought to be protective against dementia, but now thought to promote it) may have had a marked effect.
The authors do not tell us why or how education should be a protective effect against dementia. Are neurons like muscles that atrophy if not used? Surveys have repeatedly shown that the educated are less susceptible to dementia than the uneducated, though we must always remember that statistical association is not causation.
However, pessimists need not despair, as there are grounds for thinking that improvement may not last. The authors warn that the huge increase in obesity and type II diabetes may reverse the trend. The fatties of today will be the dements of tomorrow, or at least of the day after tomorrow.
Experts believe they may be able to turn back the clock as much as 40 years after identifying a natural compound proven to rewind the effects of old age in mice. A protein found in all living cells called NAD could be the key to slowing down the aging process or reversing it altogether.Posted by Jill Fallon at December 20, 2013 3:05 PM | Permalink
Tests on two-year-old mice who had been given the NAD-producing compound for just one week had body tissue which resembled that of a six-month old. Professor David Sinclair, an expert in genetics at Harvard Medical School said: 'In human years, this would be like a 60-year-old converting to a 20-year-old in these specific areas.'
The compound works by restoring communication between energy cells within the body which have broken down as we get older.
Prof Sinclair added: 'The aging process we discovered is like a married couple - when they are young, they communicate well, but over time, living in close quarters for many years, communication breaks down. 'And just like with a couple, restoring communication solved the problem.
'There’s clearly much more work to be done here, but if these results stand, then many aspects of aging may be reversible if caught early.'