Acute inflammation plays an essential role in healing. When you get a cut or bruise, your immune system jumps into action to fight off potential bacterial invaders and promote tissue repair. While that often leads to swelling and pain around an injury, it’s a helpful, not harmful, part of the healing process. Chronic inflammation is another story. Also called systemic inflammation, it occurs when the inflammatory response is triggered continuously, even though there are no injuries to fight. Rather than protecting you, this type of inflammation over time can damage the heart, brain, and other organs and appears to play a role in most, if not all, chronic diseases.
There is a link between diet and chronic inflammation. Foods high in saturated fat, including red meat, butter, eggs, whole milk, and cheese, are believed to contribute to inflammation, while fresh fruits and vegetables, whole grains, and healthy fats (like those found in olive oil and avocados) may dampen inflammation. In particular, berries, grapes, orange juice, seafood, nuts, and green tea have been shown to have anti-inflammatory properties, lending support to the notion that inflammation can be controlled in part through a healthy diet. It's unlikely, however, that any single food in isolation can either bring on or reduce inflammation.
Your weight is one of the factors that has a direct impact on inflammation. Research shows that obesity can trigger low-grade chronic inflammation in the liver, pancreas, brain, and other organs, which in turn increases the risk of insulin resistance and type 2 diabetes. The good news: Losing weight can help reduce inflammation. In a study of 218 overweight or obese postmenopausal women published in the journal Cancer Prevention Research, those who lost at least 5 to 10 percent of their body weight had a significant reduction in inflammatory markers.
Acute inflammation due to a wound or other injury can cause swelling and pain; if the inflammation is severe, it can also lead to exhaustion and fever. Joint inflammation from conditions such as rheumatoid arthritis and psoriatic arthritis can also be very painful. In contrast, low-grade, chronic inflammation doesn’t cause pain or visible physical symptoms. Like high blood pressure, it’s sometimes called a “silent killer” because its effects can go undetected.
But it can be controlled by addressing the underlying causes, such as allergens, infection, and obesity, as well as lifestyle factors such as poor diet, lack of exercise, smoking, and stress, all of which are associated with chronic inflammation. Adopting healthier behaviors can help reduce both inflammation and the accompanying risk of diseases like type 2 diabetes and heart disease.
Effective treatments include over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil), aspirin (Excedrin or Bayer), and naproxen (Aleve). Acetaminophen (Tylenol) can also help ease pain (though it doesn’t affect inflammation) and is safer for people at risk of stomach bleeding or who have high blood pressure or kidney problems. Applying ice or heat can also help.
In addition to its link to cardiovascular disease, type 2 diabetes, and cancer—plus its well-known role in autoimmune diseases including multiple sclerosis, rheumatoid arthritis, and psoriasis—inflammation also appears to play a role in certain mental-health conditions, including depression. For example, a small study in JAMA Psychiatry found that people experiencing an episode of clinical depression had 30 percent higher levels of a marker of brain inflammation (as measured by PET scans of key brain areas) compared with people who did not have depression. Chronic inflammation is also believed to contribute to Alzheimer’s disease.