Reduction of a protein in cerebrospinal fluid called brain-derived neurotrophic factor (BDNF) is associated with age-related cognitive decline, report scientists at the University of Washington School of Medicine in Seattle. The study confirms earlier research findings of low levels of BDNF in the cerebrospinal fluid of people with Alzheimer’s disease. Now, scientists have found reduced BDNF in older adults, including cognitively normal ones across the lifespan.
The researchers compared BDNF levels in the cerebrospinal fluid of 128 cognitively normal people, 21 with Alzheimer’s, and 9 with mild cognitive impairment, who were given standard tests of memory and cognition. The scientists found that, as the normal participants aged, not only did their test scores fall, but also BDNF levels were lower.
The findings suggest that reduced secretion of BDNF is associated with age-related cognitive decline in the absence of dementia or MCI and independent of the presence of the APOE e4 allele and the BDNF variant. The authors conclude that further studies are needed to validate their results. If these results are validated, scientists can look for ways to increase levels of BDNF to determine whether this restores cognition or slows its decline.
Li, G., et al. Cerebrospinal fluid concentration of brain-derived neurotrophic factor and cognitive function in non-demented subjects. PloS One. 2009. 4(5):e5424.