by Paul Reynolds, PhD
Inflammation is a vital response of the immune system to infection or injury, designed to protect the body and promote healing. However, when inflammation becomes chronic, it can lead to a host of health problems, particularly in the context of metabolic health. Chronic low-grade inflammation, often referred to as “meta-inflammation,” has been increasingly recognized as a critical factor in the development and progression of various metabolic diseases, including obesity, type 2 diabetes, and cardiovascular diseases.
The role of chronic low-grade inflammation in metabolic disease
Chronic low-grade inflammation differs significantly from acute inflammation. While acute inflammation is typically a short-term response to injury or infection, chronic low-grade inflammation persists over a long period, often without any clear external cause. This type of inflammation is subtle, involving only slightly elevated levels of inflammatory markers such as C-reactive protein (CRP) and certain inflammatory molecules called cytokines, but it can have profound effects on the body.
Research has shown that chronic low-grade inflammation is closely associated with metabolic syndrome, a cluster of conditions that includes obesity, insulin resistance, hypertension, and dyslipidemia, a condition in which there are abnormal levels of lipids in the blood. This inflammatory state often originates from excess visceral fat, which not only stores energy but also actively secretes various inflammatory cytokines into the bloodstream.
Mechanisms linking inflammation and metabolic dysfunction
Several theories have been proposed to explain how chronic low-grade inflammation contributes to metabolic dysfunction. On the cellular level, one key player is the transcription factor NF-κB, the master regulator of the inflammatory response. Activation of NF-κB in the fat, liver, and muscle has been linked to insulin resistance, a hallmark of metabolic disease.
Another important factor is the role of macrophages, immune cells that infiltrate fatty tissue in response to metabolic stress. Certain stimuli can transform these macrophages into a pro-inflammatory state, releasing cytokines that worsen insulin resistance and other metabolic disturbances.
Consequences of chronic inflammation on metabolic health
The persistent inflammation associated with obesity and metabolic syndrome has far-reaching consequences. For example, it has been linked to the progression of atherosclerosis, a leading cause of cardiovascular disease. Inflammation can promote the formation of plaques in the arteries, increasing the risk of heart attacks and strokes. Additionally, chronic low-grade inflammation can contribute to the development of type 2 diabetes by impairing insulin signaling, leading to elevated blood glucose levels and further metabolic imbalance.
How do I know if I have chronic low-grade inflammation?
Determining whether you have low-grade inflammation at home can be challenging because it typically requires specific medical tests that are not available for home use. Such tests exist, but everyday screening for inflammation is most likely done by looking at general metabolic metrics such as fasting blood glucose, blood cholesterol, and blood pressure. As a general home-based approach, any metabolic assessment gone awry can be looked at as a type of inflammation, despite its primary cause. For example, here are some indirect ways to assess your risk for chronic low-grade inflammation:
1. Monitor common symptoms of metabolic and immune health:
Persistent fatigue: Chronic low-grade inflammation can cause ongoing tiredness that doesn't improve with rest.
Body aches and pains: Unexplained joint or muscle pain, especially if it's persistent, can be a sign of low-grade inflammation.
Digestive issues: Symptoms like bloating, diarrhea, or constipation can indicate inflammation in the digestive tract.
Skin problems: Conditions like acne, eczema, or psoriasis can flare up due to inflammation.
Frequent infections: Weakened immune system due to chronic inflammation might lead to more frequent colds, flu, or infections.
2. Track your weight and waist circumference:
Obesity, particularly abdominal obesity, is strongly linked to chronic low-grade inflammation. A waist circumference that gets steadily larger over time can be an indicator of inflammation.
Strategies to combat metabolic inflammation
Given the central role of inflammation in metabolic diseases, strategies to reduce inflammation are increasingly seen as essential components of metabolic health management. Likewise, lifestyle interventions that support better metabolic health will help reduce chronic low-grade inflammation.
Regular physical activity has been shown to reduce inflammation and improve metabolic health outcomes.
A metabolic health diet rich in fiber and anti-inflammatory foods such as whole grains, healthy fats (like omega-3s), fruits, and vegetables can help lower CRP levels and other markers of inflammation. Diets high in ultra-processed foods, sugars, and unhealthy fats can contribute to inflammation.
Excess weight can contribute to inflammation, as well. Shedding excess weight reduces the body’s inflammatory response.
Chronic stress can lead to increased inflammatory markers in the body. Practices like mindfulness, meditation, or yoga can help reduce stress.
Conclusion
Chronic low-grade inflammation plays a pivotal role in the development and progression of metabolic diseases. Understanding the mechanisms that link inflammation to metabolic dysfunction can lead to better targets that may prevent and treat conditions like obesity, type 2 diabetes, and cardiovascular disease. Combating inflammation through lifestyle changes also offers a promising avenue for improving metabolic health and reducing the burden of these chronic diseases.
About the author: Dr. Paul Reynolds earned a Ph.D. in molecular and developmental biology, with his post-doctoral work focusing on pulmonary inflammation. Currently a professor at Brigham Young University, Dr. Reynolds studies inflammation and glycation, specifically how exposure to particulates (personal air pollution) influences health. He frequently publishes scientific reports and presents at meetings on the topics of inflammation during hyperglycemia and how ketogenic states mitigate inflammatory outcomes.