Acute inflammation is the body's natural response to tissue damage. Its purpose is to defend the body against harmful substances, dispose of dead or dying tissue and to promote the renewal of normal tissue. Therefore, inflammation is normal if we are ill from a virus or bacterial infection or we injure ourselves.
However, chronic inflammation is different. Chronic inflammation is involved in many autoimmune diseases including rheumatoid arthritis, allergies and even some cancers. Mounting evidence is now showing that chronic inflammation is also likely part of the Alzheimer’s puzzle.
In 2010, Karl Herrup, the chair of the Department of Cell Biology and Neuroscience at Rutgers University, wrote that he believes "...three key steps…are needed for an individual to progress …to the full spectrum of Alzheimer’s clinical symptoms: an initiating injury that is probably vascular in nature; an inflammatory response that is both chronic and unique to Alzheimer’s; and a cellular change of state, a one-way cell biological door that permanently alters the physiology of neurons and several other cell types in the Alzheimer’s disease brain."
Now a new study using mice has shown that if the brain suffers chronic inflammation in the early years, Alzheimer’s disease is more likely to develop. An article in Nursing Times reports on a study led by Dr Irene Knuesel of the University of Zurich in Switzerland. Knuesel says evidence from the mouse studies make it “…likely that chronic inflammation due to infection could be an early event in the development of Alzheimer’s disease.”
The study said that the effect was made much stronger if there is a repeat of this challenge to the immune system during adulthood. According to the article, “Mice which had their genes modified to produce a human form of the Alzheimer’s-associated brain protein amyloid-beta demonstrated the most notable reaction.”
Non-steroidal anti-inflammatory drugs
There has been considerable controversy though the years about the potential for non-steroidal anti-inflammatory drugs, known as NSAIDS, and their potential to stave off Alzheimer’s disease. Frontiers in Aging Neuroscience published an article stating that there is evidence that NSAIDS could be helpful in preventing Alzheimer’s, but the exact mechanism is not fully understood. There have also been studies refuting this evidence, so it is not generally recommended that people take the drugs, available over-the-counter and by prescription, unless they have an illness or injury requiring this treatment. Their physician should be consulted to make sure the drug is safe for them to take.
As the saying goes, the jury is still out on NSAIDS and their effect on potential Alzheimer’s. It does seem that, like so many diseases, AD likely has more than one trigger.