Inflammation is the body’s natural response to an injury or infection. Unfortunately, too much of an inflammatory response, also known as chronic inflammation, can damage our health and result in life-threatening conditions like diabetes, heart disease, and different types of cancer by attacking our body’s greatest defense: white blood cells.

Researchers led by Sian Richardson and Dr. Chris Ford, from the University of Liverpool's Institute of Ageing and Chronic Disease, recently analyzed the link between human inflammatory response and consumption of polyphenols, plant micronutrients that protect the body from harmful pathogens.

The research team focused heavily on different potencies of polyphenols and how they correlated to the release of cytokines, a marker of inflammation. White blood cells, known as T-cells, signal cytokines while scanning for cellular abnormalities. This triggers cell-to-cell communication during immune responses and stimulates cells that move toward inflammation, infection, or trauma. They found that the release of cytokines depends heavily on fruit and vegetable intake.

"The results of our study suggest that polyphenols derived from onions, turmeric, red grapes, green tea and açai berries may help reduce the release of pro-inflammatory mediators in people at risk of chronic inflammation,” said Richardson in a statement.

Aside from fruits and vegetables, polyphenols are found abundantly in dark chocolate. In fact, researchers from Sapienza University recently examined dark chocolate consumption and how its concentration of polyphenols can affect our health. Participants who ate dark chocolate with 85 percent cocoa before walking on a treadmill were able to reduce oxidation in their blood, which led to more nitric oxide, a gas that expands blood vessels and improves blood flow.  

The European Journal of Clinical Nutrition ranked 100 of the richest dietary sources of polyphenols to tell consumers which part of the supermarket is hiding the best antioxidants. Although dark chocolate does contain an average of 1,664 milligrams of polyphenols per 100 grams, it only ranks eighth on the list. The seasonings cloves, dried peppermint, Mexican oregano, and celery seed all have higher concentrations of polyphenols.

"Older people are more susceptible to chronic inflammation and as such they may benefit from supplementing their diets with isorhamnetin, resveratrol, curcumin, and vanillic acid or with food sources that yield these bioactive molecules."

While dark chocolate, Bing cherries, and green tea lower our risk for chronic inflammatory diseases such as rheumatoid arthritis and multiple sclerosis, there are also foods that can increase inflammation. According to the Arthritis Foundation, they include anything containing high levels of sugar, saturated fats, trans fats, omega 6 fatty acids, refined carbohydrates, MSG, gluten and casein, aspartame, and alcohol.

Source: McArdle F, Richardson S, Ford C, et al. Identification of (Poly)phenol Treatments that Modulate the Release of Pro-Inflammatory Cytokines by Human Lymphocytes. British Journal of Nutrition . 2016.