Preventing cognitive decline is possible, and the solution may not involve fancy new medications with unknown side effects.
An article in the Journal of the American Medical Association cites numerous studies that argue that the brain changes that have been the focus of so much attention (neurofibrillary tangles and plaques) are not the whole story.
Pathology is not destiny. So say the more than 1200 brains autopsied so far as part of the Rush Memory and Aging Project and the Religious Orders Study, a pair of massive prospective studies that have tracked the cognitive status of nearly 3000 elders for about 2 decades (Bennett DA et al. Curr Alzheimer Res. 2012;9:646-663, and Bennett DA et al. Curr Alzheimer Res. 2012;9:628- 645).
Autopsies showed that some mentally spry participants had extensive signs of cellular neuropathologies such as Lewy bodies or those related to Alzheimer or vascular disease. But others with substantial cognitive decline in their later years had few signs of these cellular abnormalities, explained David Bennett, MD, director of the Rush Alzheimer’s Disease Center at Rush University in Chicago and lead investigator of the studies.
A number of studies (Wilson RS et al. Neurology. 2013;81[ 4]:314-321 , Wilson RS et al. Psychol Aging. 2015;30:74-80, and Windsor TD et al. Dev Psychol. 2015;51: 975-986) have suggested that certain key factors can have a powerful effect that can prevent cognitive decline.
- Exercise – Regular aerobic physical exercise (30 minutes a day).
- Social Interaction – Regular social interaction can have a profound impact on cognitive function. See below.
- Conscientiousness – Continuing to follow routines and taking care of oneself and one’s affairs.
- Sense of Purpose – Having a sense of goals and direction for one’s life. Perhaps associated with faith, or volunteering, or mentorship.
- Diet – Particularly the Mediterranean Diet
The article suggests that one way that these factors may affect cognitive function is by increasing levels of brain derived neurotrophic factor (BDNF) which is a kind of brain growth factor.
New results from the Framingham Heart Study presented at the recent American Neurological Association meeting showed that social support for elders increases levels of the protein called brain-derived neurotrophic factor (BDNF) and reduces their risk of dementia and stroke. The converse also holds true for elders without social support, according to work by Sudha Seshadri, MD, a professor of neurology at Boston University, and her colleagues. Bennett’s soon to be published study also reports that higher BDNF expression is associated with slower cognitive decline in the face of brain pathology.
Other protective factors may be important including vascular endothelial growth factor (VEGF) (higher levels are associated with exercise and cardiac health – another reason it is important to remain physically active) and a healthy immune system.
Kuehn BM. The Brain Fights Back: New Approaches to Mitigating Cognitive Decline.JAMA. Published online November 25, 2015. doi:10.1001/jama.2015.15390.