Cognitive function can begin to decline as early as age 45
A recent study analyzing cognitive function among middle-aged people found that the brain’s functionality can begin to deteriorate as early as age 45. The study, conducted by University College London researchers, examined the memory, vocabulary and comprehension skills of nearly 7,400 British civil servants (28 percent women) between the ages of 45 and 70.
Data collection began in 1997 and was conducted in three phases over a decade—researchers were able to obtain complete data (all three phases) for 4,675 (63 percent) of participants, most of whom were younger. Data were analyzed by age (five-year increments) as well as by education level and gender. Over the decade, older participants experienced faster cognitive decline than younger participants, though vocabulary declined similarly in all age groups.
Overall, there was a 10 percent decline in mental reasoning among participants aged 65-70 and a four percent decline among those aged 45-49. The study also found that cross sectional data cannot provide reliable estimates of age-related cognitive decline because life experiences (e.g., quality of education, nutrition, and socioeconomic circumstances) vary too greatly among each cohort. While the cognitive decline percentage for younger participants is small, the findings suggest that such decline can begin early in life. This does not, however, indicate a link to early onset of mental illnesses such as dementia or Alzheimer’s.
The authors conclude that to prevent rapid and/or early-onset cognitive decline, people should adopt a healthy lifestyle of good nutrition (including many fruits and vegetables) and daily exercise.