Inflammation is associated with lower intelligence and premature death, according to Swedish researchers from the Karolinska Institute in Stockholm, Sweden.
“Those with low-grade inflammation performed more poorly on standardized intelligence tests, even after excluding those with signs of current illness. Inflammation also predicted an increased risk of premature death,” said lead researcher Dr. Hakan Karlsson.
When the body is healthy, chemicals from white blood cells are released in order to protect the body from any foreign substances. This process goes into action when a person is sick or sprains an ankle.
However, when this normal bodily function is sprung into overdrive—whether from exposure to toxins, allergens, stress, lack of exercise, or unhealthy eating habits—the white blood cells and their inflammatory chemicals run amok and damage the body’s tissues, causing chronic inflammation.
It is this ‘silent inflammation’ that is so dangerous, which creates chronic illness with no outward signs, and as shown in the results of this study, is even capable of lowering human intelligence.
In this study, scientists examined large population-based registers that featured data collected over many decades. Measures of intelligence and inflammation were observed in nearly 50,000 young men between the ages of 18 and 20, and their deaths over next 35 years were also recorded.
“Although we knew that inflammation associated with infection or cardiovascular disease could impair brain function, this is the first time that similar associations have been shown in healthy young people,” said Dr Karlsson. “This suggests that even low levels of inflammation can have detrimental consequences for health and brain function.”
“Since low-grade inflammation appears to be hazardous, it is also important to determine its causes,” added Dr. Karlsson. “One interesting possibility is the role of environmental factors during childhood.”
In the featured study, childhood socioeconomic status predicted the level of inflammation seen in young adulthood. For example, children of farmers had higher levels of inflammation than those whose fathers were non-manual workers.
“It’s possible that these boys were exposed to more toxins, allergens or infectious agents in childhood, leading to greater inflammation and its negative effects later in life,” said Dr. Karlsson.
Dr. Michelle Luciano, from the Centre for Cognitive Ageing and Cognitive Epidemiology at the University of Edinburgh, said “This is an important finding because it is the largest study to date to show that low-grade inflammation in young adulthood is associated with intelligence and mortality. An interesting question now is whether the effects of a less healthy childhood environment on inflammation persist into middle age and beyond,” she added.
There are many simple things people can do to reduce low-grade chronic inflammation in the body. Eating lots of fruits, vegetables, and wild seafood and getting plenty of exercise and rest are just a few easy steps toward reducing inflammation and fostering better brain health.
This study was recently published recently in Brain, Behavior and Immunity (August,24:868–873).