The Food Inflammation Index (FII), also known as the Dietary Inflammatory Index (DII), is a scoring system that assesses the inflammatory potential of a diet. It provides a numerical score indicating how a person’s dietary pattern influences inflammation. This tool helps researchers and health professionals understand the relationship between diet, inflammation, and health outcomes.
Understanding Dietary Inflammation
Inflammation is a natural response of the immune system to injury, infection, or irritation. Acute inflammation is a short-term, protective process that helps the body heal. For example, swelling and redness around a cut are signs of acute inflammation.
Prolonged or persistent inflammation transitions into chronic inflammation, which can be detrimental to health. This low-grade, long-term inflammation is linked to the development of various chronic conditions, including cardiovascular disease, obesity, type 2 diabetes, certain cancers, and inflammatory bowel diseases. Diet plays a significant role in modulating this inflammatory response. Certain foods can either promote or reduce inflammation, impacting overall health over time.
How the Food Inflammation Index is Calculated
The FII is calculated based on the inflammatory potential of 45 different food components and nutrients. These include macronutrients (carbohydrates, proteins, fats), micronutrients (vitamins, minerals), and other components like fiber and flavonoids. Researchers assign scores to these components based on scientific literature, examining their effects on six established inflammatory biomarkers: C-reactive protein (CRP), interleukin-1 beta (IL-1β), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-α).
To calculate an FII score, daily intake of each food parameter is compared to a “standard global mean” and adjusted using a standard deviation to create a Z-score. This Z-score is converted into a percentile score, then multiplied by the specific inflammatory effect score for that food parameter. These individual food parameter scores are summed to produce an overall FII score. A more positive FII score indicates a pro-inflammatory diet, while a more negative score suggests an anti-inflammatory dietary pattern. The theoretical range for FII scores varies, but for scores derived from 25–30 food parameters, it typically falls between approximately -5.5 and +5.5.
Pro-Inflammatory and Anti-Inflammatory Foods
Foods that increase inflammation and contribute to a higher FII score often include highly processed items. Examples are processed meats, sugary beverages, refined grains, and fried foods. Foods high in saturated fats, trans fats, and excessive sodium also fall into the pro-inflammatory category.
Conversely, foods known for anti-inflammatory properties, contributing to a lower (more negative) FII score, are whole and nutrient-dense. This group includes fatty fish like salmon, mackerel, and sardines, rich in omega-3 fatty acids. Berries, leafy green vegetables, tomatoes, and dark chocolate are recognized for their antioxidant content. Other beneficial components include ginger, turmeric, extra virgin olive oil, nuts, seeds, and foods high in fiber, magnesium, and beta-carotene.
Incorporating the FII into Your Eating Habits
The FII principles can guide healthier dietary choices. A primary strategy involves emphasizing whole, unprocessed foods. This means prioritizing fruits, vegetables, whole grains, lean proteins, and healthy fats.
Increasing anti-inflammatory food intake can help lower your FII score. This might involve adding more fatty fish, incorporating a wider variety of colorful fruits and vegetables, and using anti-inflammatory herbs and spices like turmeric and ginger in your cooking. Reducing pro-inflammatory foods, such as processed snacks, sugary drinks, and refined carbohydrates, is also beneficial. Making gradual, sustainable changes, rather than drastic overhauls, generally leads to lasting results.
Important Considerations for the FII
While the FII offers a valuable framework for understanding dietary inflammation, it should be interpreted with a balanced perspective. Individual responses to food vary due to genetic makeup, gut microbiome composition, and other lifestyle factors like stress and physical activity.
The FII provides an estimation of a diet’s inflammatory potential and is not intended as a definitive diagnosis of health conditions. It functions best as part of a broader approach to health, complementing a balanced diet and, when necessary, professional medical or nutritional advice. The scientific understanding behind the FII continues to evolve as more research emerges.