Significant research areas in DARC II:
The "Failure of Success" vs "Success of Success"
It has been postulated that life extension would increase chances of being frail and developing a vegetative state, with huge personal and societal costs. Research in the mid-1990’s looked into the “Failure of Success” hypothesis proposing that an increased longevity meant that the health of older people was on the decline.
We hypothesize that, for humans, the exceptionally old generally enjoy the “Success of Success”, i.e., an increasing proportion of the population living to the highest ages is accompanied by a concurrent postponement of physical and cognitive disability. So far, the human data in this are sparse and not consistent as pointed out in our Lancet review on the challenges associated with the aging populations.
The planning of and policy development for future care of the oldest-old will be highly dependent on whether populations are experiencing the “Failure of Success” or the “Success of Success” as they reach the highest ages.
- Are cognitive abilities better or worse preserved in the new large cohorts of older adults than in previous cohorts?
Determinants of variation in cognitive functioning among the elderly and the oldest-old
One of the greatest fears we have in getting older is loss of cognitive function and numerous national and international committees have identified understanding the nature of late-life cognitive decline to be a major public health goal.
Cognitive decline is not only associated with the onset of cognitive impairment and dementia. But also associated with reduced longevity, increased chronic morbidity, and loss of well-being. Nonetheless, even though some loss in cognitive function with age is to be expected, many older individuals will not experience a level of cognitive decline that will impair their ability to live independently and happily. There is a clear need to better understand the nature, origins and consequences of age-related cognitive decline throughout the full range of cognitive ability so that we might be in a better position to develop effective preventive measures for those who might otherwise experience significant levels of cognitive decline.
At the molecular level there is growing evidence suggesting that increased oxidative damage in the brain and impaired mitochondrial function (mitochondria are the cellular energy factories) play important roles in deficient cognitive function. Thus, another component of the research in DARC II will be on a better understanding of the molecular processes involved in the repair of oxidative damage and maintenance of mitochondrial function at the highest ages.
Change in cognitive function in late life after exposure to anesthesia and surgery
The impact of genome and mitochondrial maintenance on cognitive function in old individuals
Molecular and biochemical characterization of DNA maintenance proteins associated with cognitive function
Life course environmental factors and behavioral determinants of variation in cognitive functioning
The focus of DARC II is on the development and determinants of variance in cognitive functioning late in life - in particular determinants of good cognitive functioning. One component is on the development over and within cohorts of older Danes including international comparisons. Another major component of the research is seeking explanations for the late life variation in cognition – and these explanations will be sought over the life course. It is well-documented that cognitive decline starts already in mid-life, that early life factors such as education is associated with later life cognition and that cognitive function late in life has a high heritability (approximately 50%).