Chronic systemic inflammation occurs when the body releases pro-inflammatory cells activated by the immune system. Inflammation is extensively studied, and its effects are well documented and scientifically backed. Inflammation can affect every body system, and increase risk for almost every disease. The inflammatory process is a complex series of reactions, each previous reaction affecting the next. While the complexity of this immune response makes the study of inflammation extremely broad, it also allows scientists to study the inflammatory cascade in specific steps – meaning that there are several potential therapies that may correspond with each step. Said differently, the complexity of the inflammatory response means there are more areas drugs could potentially interfere.
Perhaps one of the heaviest researched of inflammation today is the effects that inflammation have on the nervous system and psychological components of human physiology. A 2010 study reports that inflammation may have detrimental effects on intelligence, and even lead to premature death. Swedish scientists from the Karolinska Institute of Stockholm, Sweden found that those with low-grade inflammation perform poorly on standardized intelligence tests. The study was done using large population based registers that contained data collected over several decades. Nearly 50,000 men between the ages of 18 and 20 were included in the study, and deaths of the participants were recorded over 35 years.
It was previously documented that inflammation is associated with infection and heart disease negatively affects brain function, but the Karolinska Institute study demonstrated that this link exists in healthy adults, as well. The data seems to suggest that even low levels of inflammation affect brain function. Researchers then asked what factors could be causing this low-grade inflammation, and how these risk factors could be minimized. One theory is that environmental factors like pollution exposure during childhood may trigger low-grade inflammatory responses in healthy adults. This is an interesting theory, as recent studies also show that pollution exposure during childhood may be linked to autism. The socio-economic theory suggests that inflammation levels are associated with social class. This theory may hold some truth, as low socio-economic status is associated with poor nutrition and lower education – which can directly influence the immune system. Furthermore, children of farmers were shown to have higher inflammatory levels than children whose fathers were non-manual laborers. It’s likely that this group of boys were exposed to higher levels of toxins during childhood – negatively affecting immune regularity later in life.
The results of the study are valuable in examining the link between low-grade inflammation and brain function; however, researchers are still split as to whether the effects of a less healthy childhood environment on inflammation persists into middle age and even later in adulthood. If a clear link is discovered, then more effective preventative strategies can be implemented during childhood. Inflammation is a complex process, and there are several environmental, lifestyle, and genetic factors that can have significant effects on health outcomes and overall lifespan. Although not all of these factors are controllable, positively influencing the ones that can be controlled may result in a longer life for a large sector of the human race.