This article is more than 5 years old. Information may no longer be current.

Chronic inflammation may negatively affect thinking, memory

Middle-aged individuals with chronic inflammation may develop problems with thinking and memory skills later in life, according to findings published in Neurology.

“Chronic inflammation is tough on the body, and can damage joints, internal organs, tissue and cells,” Keenan A. Walker, PhD, of Johns Hopkins University, said in a press release. “It can also lead to heart disease, stroke and cancer. While other studies have looked at chronic inflammation and its effects on the brain in older people, our large study investigated chronic inflammation beginning in middle age and showed that it may contribute to cognitive decline in the decades leading up to old age.”

Walker and colleagues enrolled 12,336 participants aged between 45 and 65 years (baseline age, 56.8 years; 21% black; 56% women) and followed them for about 20 years.

At the beginning of the study, the researchers took blood samples and measured four inflammatory biomarkers, including fibrinogen, white blood cell count, von Willebrand factor and factor VIII. They used the four blood biomarkers to create an inflammation composite score. Three years afterwards, they measured C-reactive protein.

Participants were categorized into four groups

The researchers also assessed cognition in terms of memory, executive function and language over three visits spanning 20 years.

The analysis was adjusted for demographic variables, vascular risk factors and comorbidities, including education, heart disease and high BP.

Over the study course, there was an 8% higher decline in thinking and memory skills among the participants with the highest levels of inflammation biomarkers than those with the lowest levels. Additionally, there was a 12% higher decrease in thinking and memory skills among participants with the highest C-reactive protein levels than those with the lowest levels.

Higher midlife inflammatory markers were most consistently tied to declines in memory in cognitive domain-specific analyses, according to the researchers.

“Overall, the additional change in thinking and memory skills associated with chronic inflammation was modest, but it was greater than what has been seen previously associated with high BP in middle age,” Walker said in the release.

“Many of the processes that can lead to a decline in thinking and memory skills are believed to begin in middle age, and it is in middle age that they may also be most responsive to intervention,” Walker added. “Our results show that chronic inflammation may be an important target for intervention. However, it’s also possible that chronic inflammation is not a cause and instead a marker of, or even a response to, neurodegenerative brain diseases that can lead to cognitive decline.”

Studies in the future should assess thinking and memory skills more frequently and examine a greater variety of inflammation markers in the blood, according to the researchers. – by Alaina Tedesco

Disclosures: Walker reports no relevant financial disclosures. Please see study for all other authors’ relevant financial disclosures.