This week on our nationally syndicated radio show, our guest describes the causes and consequences of silent inflammation. Usually, inflammation (redness, swelling, heat, pain) is a tool the immune system uses to fight infection. But what happens when it gets out of control?
A number of factors might help explain how an immune system creating acute inflammation in response to infection might not be able to calm itself afterwards. Viruses or bacteria can trigger a cytokine storm that may throw the body out of balance. Air and water pollution or exposure to chemicals in common products such as fast food packaging may also encourage this trend. In addition, our modern American lifestyle, with too little physical activity and too much ultra-processed foods, probably contributes. What can we do to recognize and counteract this problem?
Our guest, Dr. Shilpa Ravella, shares a story about a close friend from medical school who suddenly developed an alarming condition. He ultimately became unable to hold up his head and required a brace from his waist to his skull. Doctors had difficulty diagnosing the problem, which was eventually declared an atypical autoimmune disease. It seems he was the victim of an especially vicious case of silent inflammation.
Although the story focused on a very unusual case, hidden, lingering inflammation is at the root of many of our most common chronic conditions. When the lining of blood vessels (endothelium) becomes inflamed, the consequence can be cardiovascular complications, including heart disease and stroke. Statins may benefit heart patients partly because they reduce inflammation.
When our digestive tracts become chronically inflamed, the results can be devastating…from irritable bowel syndrome to inflammatory bowel diseases like Crohn’s disease or ulcerative colitis. In the brain, inflammation may contribute to dementia.
The microbes that populate our digestive tracts are in a constant, intimate conversation with the immune system cells that surround it. Consequently, our dietary choices are critical. Maintaining a healthy and diverse microbiota is key to keeping inflammation under control.
An American diet full of meat and ultra-processed foods leads to an impoverished microbiota. Investigators demonstrated this when they had two groups of people swap diets for two weeks. When people from Pittsburgh ate the kind of food popular in South Africa, full of whole grains and vegetables, they increased their microbial diversity. On the other hand, the South Africans who consumed burgers and French fries, among other foods, for two weeks ended up with less diverse microbes. Scientists are still exploring how this affects silent inflammation. Most agree, though, that a diet consisting mostly of whole foods, as unprocessed as possible, rich in fiber, offers significant advantages.
Doctors don’t often test for silent inflammation because it is difficult to measure. However, cardiologists may test for high-sensitivity C-reactive protein (hs-CRP), a way of assessing how inflammation may be affecting the blood vessels and the heart. Other red flags include belly fat. This indicates visceral fat that acts to ramp up inflammation in many cases. Another clue: high blood sugar. When the pancreas isn’t able to produce enough insulin to lower circulating glucose, it is often a signal that it is struggling with inflammation.
Shilpa Ravella, MD, is a transplant gastroenterologist with expertise in nutrition and an Assistant Professor of Medicine in the Division of Digestive and Liver Diseases at Columbia University Medical Center. Her TED-Ed lesson, ‘How the Food You Eat Affects Your Gut,’ has garnered over five million views.
Dr. Ravella is the author of A Silent Fire: The Story of Inflammation, Diet, and Disease.
Her website is: shilparavella.com The photograph of Dr. Ravella is copyright Anshul Mathur.