US study finds possible tie between immune system responses and neurodegeneration. 

While shrunken heads are the province of faraway tribes and distant times, shrunken brains happen to be an unfortunate fact of everyday life. The normal brain shrinks significantly with age, some regions by as much as 25% before the age of 80.

New research, however, published in the journal Neurology, finds that inflammation in middle life may be exacerbating not just brain shrinkage with age, but also contributing to a doddery memory.

The study, led by Keenan Walker from the Department of Neurology at Johns Hopkins University School of Medicine in the US, analysed data from the Atherosclerosis Risk in Communities (ARIC) study. ARIC began in 1987, recruiting participants from Maryland, Minnesota, North Carolina and Mississippi.

Between 1987 and 1989, 15,792 middle-aged adults were assessed for baseline levels of a range of inflammation markers, including white blood cell count, and clotting proteins called fibrinogen and Von Willebrand factor.

Twenty-four years later, between 2011 and 2013, a cohort of 1,633 of the original participants had MRI brain scans. They also underwent memory testing using the delayed word recall test, which asks subjects to memorise 10 words and repeat them a short time later.

The researchers found that higher inflammation scores on the baseline tests were associated with reduced size of various brain regions showing up on MRI.

Read the full article in Cosmos magazine here