13.3: Phytochemicals

Phytochemicals are chemicals in plants that may provide some health benefits. They are not considered nutrients as they are not required to sustain life; however, consuming foods with phytochemicals on a regular basis has been linked to reducing risk for cardiovascular disease, diabetes, and cancer, as well as age-related physical and mental decline. Carotenoids are one type of phytochemical. Phytochemicals also include indoles, lignans, phytoestrogens, stanols, saponins, terpenes, flavonoids, carotenoids, anthocyanidins, phenolic acids, and many more. Phytochemicals are found in fruits, vegetables, grains, seeds, nuts, and legumes; and they are what give plants their color.

• Carotenoids are found in foods that are red, orange, and deep green.
• Flavonoids are found in berries, black and green tea, purple grapes, and chocolate.
• Phenolic acids are found in coffee beans and fruits.
• Phytoestrogens are found in soy products.
• Indoles are found in garlic, leeks, and onions.

Phytochemicals are present in small amounts in the food supply, and although thousands have been and are currently being scientifically studied, their health benefits remain largely unknown. Also largely unknown is their potential for toxicity, which could be substantial if taken in large amounts in the form of supplements. Moreover, phytochemicals often act in conjunction with each other and with micronutrients. Thus, supplementing with only a few may impair the functions of other phytochemicals or micronutrients. The antioxidant vitamins are the mixture and variety of phytochemicals in foods linked to health benefits. Many phytochemicals act as antioxidants, but they have several other functions, such as mimicking hormones, altering cholesterol absorption, inhibiting inflammatory responses, and blocking certain enzymes’ actions.

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