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Plant foods contain thousands of natural chemicals. These are called phytonutrients or phytochemicals."Phyto" refers to the Greek word for plant. These chemicals help protect plants from germs, fungi, bugs, and other threats.

Fruits and vegetables contain phytonutrients. Other plant-based foods also contain phytonutrients, such as:

  • Whole grains
  • Nuts
  • Beans
  • Tea

Phytonutrients aren't essential for keeping you alive, unlike the vitamins and minerals that plant foods contain. But when you eat or drink phytonutrients, they may help prevent disease and keep your body working properly.

More than 25,000 phytonutrients are found in plant foods. WebMD takes a look at these six important phytonutrients -- and their potential health effects:

  • Carotenoids
  • Ellagic acid
  • Flavonoids
  • Resveratrol
  • Glucosinolates
  • Phytoestrogens


More than 600 carotenoids provide yellow, orange, and red colors in fruits and vegetables.

Carotenoids act as antioxidants in your body. This means they tackle harmful free radicals that damage tissues throughout your body.

The types of carotenoids that may have other health benefits include:

Alpha-carotene, beta-carotene, and beta-cryptoxanthin. Your body can convert all of these to vitamin A. This vitamin helps keep your immune system working properly, and it's needed for eye health. Yellow and orange foods like pumpkins and carrots are good sources of alpha- and beta-carotene.

These also contain beta-cryptoxanthin, as do sweet red peppers.

Lycopene. This gives red or pink color to:

  • Tomatoes
  • Watermelon
  • Pink grapefruit

Lycopene has been linked to a lower risk of prostate cancer.

Lutein and zeaxanthin. These may help protect you from cataracts and age-related macular degeneration, which are two types of eye problems.

Good sources of these phytonutrients are greens such as:

  • Spinach
  • Kale
  • Collards

Ellagic Acid

Ellagic acid is found in a number of berries and other plant foods, especially:

  • Strawberries
  • Raspberries
  • Pomegranates

Ellagic acid may help protect against cancer through several different ways. For example, it may cause cancer cells to die. And it may help your liver neutralize cancer-causing chemicals in your system.


A large number of phytonutrients fall into the flavonoid category. They are found in a variety of plant foods.

The types of flavonoids include:

Catechins. Green tea is an especially good source of catechins. The drink may help prevent certain types of cancer.

Hesperidin. Found in citrus fruits, this flavonoid works as an antioxidant. It can reduce inflammation in the body. It may also help reduce the risk of cancer.

Flavonols. Quercetin is a well-studied type of flavonol. It is found in:

  • Apples
  • Berries
  • Grapes
  • Onions

It might help reduce people's risk of asthma, certain types of cancer, and coronary heart disease.


Resveratrol is found in:

  • Grapes
  • Purple grape juice
  • Red wine

It acts as an antioxidant and anti-inflammatory.

Some research suggests that resveratrol might reduce the risk of heart disease and cancer. And it may help extend people's life span.

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