Chronic Inflammation and Thinking/Memory Problems

Chronic inflammation is tough on the body and now through a recent study we have one more thing to be worried about. This study published in Neurology indicates that chronic inflammation in middle age may lead to problems with memory and thinking in the years leading up to old age.

There are two different kinds of inflammation. Acute inflammation occurs when a person’s immune system ramps into action in an effort to fight off injury or infection. It is short term, localized and part of a healthy immune system.

Chronic inflammation on the other hand is not considered healthy. It is low grade inflammation that will longer for months and even years throughout the body. It can be the result of a variety of autoimmune diseases, physical stress, lingering infections, exposure to polluted air, and other causes. Symptoms include stiffness, joint pain, fatigue and digestive problems.

In conjunction with the Atherosclerosis Risk in Communities (ARIC) Study, the researchers followed 12,336 middle aged individuals between 45 and 65 years for about 20 years. They took blood samples at the beginning of the study measuring four bio markers for inflammation… white blood cell count, fibrinogen (a soluble protein found in blood plasma), von Willebrand factor (a blood glycoprotein involved in stopping bleeding) and factor VIII (a blood protein involved in clotting). They then created a composite inflammation score for these four bio markers.

Three years later the researchers measured C-reactive protein which is a protein found in blood plasma whose levels rise in response to inflammation. The participants were then divided into four different groups based on the C-reactive protein levels and their composite inflammation scores.

The participants memory and thinking skills were tested at the start of the study then six to nine years later and at the studies end.

What they found was the group with the highest levels of the inflammation bio markers had an 8% steeper decline in memory and thinking skills over the length of the study compared with the lowest levels of bio markers. The group that had the highest C-reactive protein levels showed a 12% steeper decline in thinking and memory skills compared to the group with the lowest levels.

The researchers adjusted for a variety of factors that could affect thinking and memory skills such as heart disease, high blood pressure, cholesterol, and education level. Additional analysis revealed that declines associated with inflammation in thinking were most prominent in the areas of memory when compared to other aspects of thinking such as executive functioning and language.

The team noted that overall the additional change in memory and thinking skills which were associated with chronic inflammation were modest, but were greater than what had been seen earlier with high blood pressure in middle age.

It is believed that many of the processes in the body that can lead to memory and thinking skill decline beginning in middle age. It is also middle age that may be most response to interventions. The study shows that chronic inflammation may be an important target for interventions. However, they do also note that it is possible that this type of inflammation is not a cause and instead is a marker or response to neurodegenerative diseases of the brain that can lead to cognitive decline.

There was a limitation to the study which was that participants with higher levels of chronic inflammation at the beginning of the study were more likely to die or drop out before the final follow up visit. Surviving participants might not be completely representative of the general population.

Regardless, chronic inflammation takes its toll on the body affecting internal organs, tissue, cells and joints and can also lead to severe and deadly diseases. Reducing chronic inflammation involves some of the same health behaviors that are already known to be important…healthy diet including cold water fish such as wild salmon or taking a high quality omega-3 supplement, regular exercise, avoiding excessive weight gain, getting enough sleep and other healthy habits.

To view the original scientific study click below

Chronic inflammation in the etiology of disease across the life span