Overview
This lecture covers phytochemicals—compounds found in plants that may offer health benefits, their functions, and common sources in the diet.
What are Phytochemicals?
- Phytochemicals are chemicals in plants thought to provide health benefits beyond basic nutrition.
- They are found in fruits, vegetables, grains, seeds, nuts, and legumes.
- Phytochemicals include carotenoids, indoles, lignans, phytoestrogens, stanols, saponins, terpenes, flavonoids, anthocyanidins, and phenolic acids.
Functions and Actions
- Many phytochemicals act as antioxidants, reducing cellular damage from free radicals.
- Some mimic hormones, alter cholesterol absorption, inhibit inflammation, or block certain enzymes.
- Phytochemicals often act together and may interact with vitamins and minerals, enhancing or impairing functions.
Cautions and Unknowns
- Most phytochemicals are present in small amounts in food; their full health effects are not yet fully understood.
- Potential toxicity may occur if consumed in large amounts via supplements.
- Consuming a variety of whole plant foods is recommended over isolated phytochemical supplements.
Examples and Food Sources
- Carotenoids from yellow-orange fruits and leafy greens may help fight cancer.
- Indoles in cruciferous vegetables may inhibit hormone-related cancer and tumor growth.
- Phytoestrogens in soybeans, berries, and garlic may lower risks for osteoporosis, heart disease, and some cancers.
- Stanols from grains, nuts, and legumes may lower cholesterol and heart disease risk.
- Saponins in beans and lentils may lower blood lipids, cancer risk, and blood glucose response.
- Terpenes from citrus fruits may slow cancer progression and boost immunity.
- Flavonoids in fruits, vegetables, and teas may support immunity and prevent cancer cell growth.
- Anthocyanidins in colorful produce may prevent cardiovascular disease and reduce cancer cell proliferation.
- Phenolic acids in coffee, vegetables, and nuts may prevent oxidative damage and promote anti-inflammatory conditions.
Key Terms & Definitions
- Phytochemical — Plant compound not essential in the diet but may promote health.
- Antioxidant — Compound that inhibits oxidation and protects cells from damage.
- Carotenoid — A class of phytochemicals that may serve as vitamin A precursors.
- Phytoestrogen — Plant-derived compound with estrogen-like activity.
- Micronutrient — Essential vitamins and minerals needed in small amounts.
Action Items / Next Steps
- Review the main phytochemical sources and their health-related functions.
- Emphasize dietary variety of plant-based foods rather than isolated supplements.