Your Brain — Use It or Lose It

Steven Dubovsky, MD

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Abstract and Introduction

Abstract

An active cognitive lifestyle does not protect against Alzheimer disease pathology, but using cognitive abilities helps men and women minimize changes in aging in different ways.

Introduction

Animal and human studies suggest that mental stimulation reduces the risk of cognitive decline. Researchers used data from a U.K. study of 13,004 older people (baseline age, ≥65) who were followed for 14 years; the brains of 329 subjects who died during follow-up were autopsied. In the current analysis, researchers examined the relationship between neuropathology and Cognitive Lifestyle Score (CLS). The CLS measures years of education, occupational complexity, and social engagement.

After adjustment for relevant medical and vascular risk factors, men with high CLS (i.e., an active cognitive lifestyle) had an 80% relative reduction in risk for microvascular disease and associated deep white-matter lesions and a 70% relative reduction in risk for lacunar infarcts, compared with low-CLS men. High-CLS women had greater brain weight (but not less-frequent cerebrovascular disease) than low-CLS women. High CLS was associated with an 80% reduction in the risk for dementia at death in men but not women. In a subsample of 72 individuals, high CLS did not protect against neuronal loss in the hippocampus. However, after adjustment for other risk factors, high CLS was associated, in both men and women, with greater neuronal density and a thicker cortical ribbon in Brodmann area 9.

Comment

It is not yet known whether an active cognitive lifestyle and social engagement directly affect the brain and cerebral vasculature, whether people who are more resilient neurologically have more active cognitive lifestyles, or whether predisposition to greater resiliency is linked to predisposition to cognitive activity. However, improvement of cognitive decline by cognitive retraining (JW Psychiatry Oct 17 2011) suggests that a two-way interaction between the environment and the brain might protect against dementia via several mechanisms.

References

  • Valenzuela MJ et al. Multiple biological pathways link cognitive lifestyle to protection from dementia. Biol Psychiatry 2012 May 1; 71:783.

  • Doraiswamy PM. Is the idle mind a devil's workshop? Biol Psychiatry 2012 May 1; 71:765.