Phytonutrients Impact on Inflammation

May 28
4 min read

What it is:

Phytonutrients, also called phytochemicals or bioactives, are naturally occurring compounds found in food that can influence biological processes in the human body. Plants produce them to protect themselves from threats such as damage, disease, and pests. Their effects can be beneficial or harmful depending on the compound, dose, and overall dietary pattern.

Around 10,000 different phytochemicals have been identified, although detailed scientific understanding currently only exists for several hundred. There is a lot more to discover. They appear in many structural forms and include alkaloids, phenolics (olive oil), carotenoids (carrots), organosulfur compounds (garlic, onion), phytosterols, catechins (EGCG), and plant-derived peptides.

Inflammation is a normal and necessary biological process involved in immune defense and tissue repair. It becomes problematic when it is chronic and low-grade, which is associated with increased risk of disease, particularly metabolic and cardiovascular conditions.

The gut plays a central role in regulating inflammation. It contains a complex immune network, mucus-producing structures, and a large microbial population. This system interacts closely with dietary compounds and produces measurable inflammatory signals.

Common biomarkers linked to chronic inflammation include C-reactive protein and interleukins. These are influenced by diet, environment, genetics, age, and prior health status, which explains large variability in individual responses.

What the science says:

Research consistently shows that phytonutrients interact with our physiology in multiple ways, particularly through immune modulation and antioxidant pathways. However, these effects depend on dietary context rather than single compounds in isolation. Although supplements can assist and top up areas of need, research consistently shows that whole foods provide complex chemical environments that interact with and support one another in ways we still don’t fully understand.

For example:

Berries (anthocyanins + flavanols + fiber matrix): Whole berries contain anthocyanins, flavanols, vitamin C, and dietary fiber that may slow intestinal transit and enhance polyphenol and antioxidant contact time with the gut microbiome. Research consistently demonstrates that consuming berries is linked to lower levels of inflammatory markers and enhanced endothelial function. These benefits are not typically replicated by taking isolated anthocyanin supplements alone, as shown in many studies. Similarly, resveratrol, found in berries, does not always exhibit the same antioxidant properties necessary to repair and recycle our mitochondria as the whole food form does.
Cocoa (epicatechins + procyanidins + lipids): Cocoa is rich in flavanols such as epicatechin and procyanidins embedded within a fat-rich matrix. Studies on cocoa consumption show improvements in cardiovascular function, which may be due to the combined effects of the components, as isolated flavanol extracts often produce weaker or less consistent effects.
Tomatoes (lycopene + carotenoids + vitamin C + fibre) Lycopene absorption increases significantly when consumed in whole tomato products, particularly when paired with dietary fats, and the presence of other carotenoids and vitamin C may also influence oxidative stability and absorption efficiency.
Green tea (EGCG + catechin family + caffeine interaction): The network of catechins, primarily EGCG, alongside caffeine and amino acids such as L-theanine has been shown to improve cognitive performance and stronger cardiometabolic outcomes.

The processing of food also matters, as it can alter its effectiveness. Ultra-processed foods, specifically, can reduce phytonutrient benefits due to multiple mechanisms, including thermal degradation, refining, oxidation, and structural breakdown of plant cell walls. This leads to lower retention of polyphenols, carotenoids, and other phytochemicals, as well as reduced fiber that supports gut microbial fermentation and metabolite production. Minimally processed foods preserve these structures, allowing for slower digestion, improved microbial interactions, and greater stability and bioavailability of the compounds in the gut.

Fiber is increasingly understood not just as a mechanical digestive aid but also as a carrier system for phytonutrient compounds. Insoluble fiber may suspend healthful compounds such as quercetin, resveratrol, catechins, lutein, lycopene, and anthocyanins in the digestive system, allowing them time to act beneficially on gut walls as they pass through.

As the gut plays a major role in regulating inflammatory signals, this is particularly important for immune function. Inflammation is influenced by a wide array of factors, including genetics, environment, age, and microbiome composition. As our current knowledge remains quite limited, consuming a variety of phytonutrient-dense foods is vital for maintaining a balanced inflammatory response.

Action points:

Focus on dietary patterns that increase exposure to diverse plants rather than isolated compounds.
Prioritize whole and minimally processed foods that retain their natural phytochemical structures, including but not limited to:
- Green tea (EGCG)
- Turmeric (curcumin) and other spices such as cinnamon, cardamom, and black pepper
- Broccoli, Brussels sprouts (sulforaphane precursors)
- Tomatoes, papaya (lycopene)
- Pomegranate (ellagic acid)
- Milk thistle (silymarin)
- Garlic and onions (organosulfur compounds)
- Also try to incorporate other plants you might not often have, such as Burdock, Ginkgo, Caper, and Aronia berries.
Include a wide range of deeply pigmented plant foods, particularly berries and purple or black plant foods, which are rich in anthocyanins, such as berries, purple cabbage, blueberries, and black rice.
Maintain a consistent intake of dietary fiber, particularly from whole-plant sources, to support gut-mediated interactions with bioactives.
Recognize that food quality matters. Indicators such as soil quality, color vibrancy, aroma intensity, and freshness may reflect differences in phytochemical density.