phytochemical

Phytochemicals are bioactive compounds produced by plants that are not essential nutrients for humans. They include a broad range of secondary metabolites found in fruits, vegetables, grains, legumes, herbs, and other plant-based foods. Major families include polyphenols, carotenoids, alkaloids, terpenoids, glucosinolates, and sulfur-containing compounds.

In plants, phytochemicals serve defensive and protective roles, contributing to color, aroma, and taste, and helping plants resist pests and stress. Phytoalexins are induced in response to infection or injury.

In humans, phytochemicals are not essential but are studied for potential health benefits, including antioxidant and anti-inflammatory effects, and possible roles in reducing chronic disease risk. Most health-related claims relate to dietary patterns or whole foods rather than isolated supplements; evidence remains mixed.

Research uses extraction, chromatography, spectroscopy, and metabolomics to identify and quantify phytochemicals and study their biological effects. The term covers thousands of compounds and is used across plant science, nutrition, pharmacognosy, and food science. While many phytochemicals show promising in vitro or animal data, translating these findings to human health requires careful, context-dependent interpretation.