Phytonutrients: Why We Should Eat the Rainbow

Have you ever wondered where plants, including fruits and vegetables, get their vibrant colors? Well, the answer is from phytonutrients! Phytonutrients (also known as phytochemicals) are compounds produced by plants that provide health benefits to our bodies and are displayed through a plant’s pigment. Phytonutrients contribute to not only a plant’s appearance, but also their taste, smell, and immune system. These compounds strengthen the plant’s immune system by protecting it from dangers such as sun damage and disease. While phytonutrients are beneficial to keeping plants healthy, when consumed by humans through a varied diet, these compounds may also aid in keeping us healthy too. Let’s explore the potential health benefits that each phytonutrient has to offer through their distinct hues.

Colorful produce.

Colorful produce.
Hannah Shifflette, ©2024, Clemson Extension


The phytonutrient group carotenoids are responsible for the bold colors in some fruits and vegetables, including those that are red. The carotenoid subgroup in red produce is called lycopene. Regular consumption of lycopene may help protect against heart disease, lung disease, prostate cancer, and sun-related skin damage. Good examples to include in your diet are strawberries, tomatoes, watermelon, and red peppers.

Orange and Yellow

The carotenoid subgroup beta-carotene is responsible for the bright pigments in orange and yellow produce. This phytonutrient found in pumpkins, sweet potatoes, carrots, and pineapples has been shown to have a positive impact on human immune systems and eye health.


The carotenoid lutein, found in leafy green vegetables such as lettuce, spinach, and kale, has been found to be essential for eye health and vision. Cruciferous green vegetables such as broccoli, Brussels sprouts, and cabbage contain the phytonutrient glucosinolate, which has been associated with cancer prevention.

Purple and Blue

Flavonoids, one of the largest groups of phytonutrients, are responsible for the bold colors of purple and blue produce. Specifically, the flavonoid subgroup called anthocyanins is present in blueberries, blackberries, eggplant, and purple cabbage. Produce rich in anthocyanins may help improve blood vessel health and brain function when consumed regularly.

White and Brown

Mushrooms, garlic, and cauliflower all contain flavonoids such as kaempferol and quercetin. These phytonutrients may help protect against hypertension, cancer, and improve bone health. Onions are known to contain the compound allicin, which has been found to have anti-tumor benefits.

Our Goal

To reap all the health benefits that colorful fruits and vegetables have to offer, we should aim to consume at least 4.5 cups every day. For some, this can be challenging, so how can we make it easier?

  1. Buy local produce to benefit your wallet and your community. When local produce is not an option, remember that frozen or canned fruits and vegetables are great, too. Just be sure to pick options without added sugar and sodium.
  2. While at the grocery store, examine your cart. Make a conscious effort to add as many different colors of fruits and vegetables as possible.
  3. Choose whole produce, including the skin. Fruit and vegetable juices can be very high in added sugar and sodium while lacking in fiber. Consuming the actual produce will ensure that you obtain all the vitamins, minerals, and fiber that the whole food has to offer.

Related factsheets:

HGIC 4017, Vary Your Veggies

HGIC 4026, Focus on Fruits

HGIC 3483, Selecting & Storing Fruits & Vegetables


  1. Anthony, Kiara. “Phytonutrients.” Healthline. Healthline Media. 25 May. 2019. Web. 26 Feb 2024.
  2. McManus, Katherine. “Phytonutrients: Paint your plate with the colors of the rainbow.” Harvard Medical School. Harvard Health Publishing® of The President and Fellows of Harvard College. 25 April. 2019. Web. 26 Feb 2024.
  3. “What are phytochemicals? (And why should you eat more of them?).” UCLA Health. UCLA Health. 10 May 2023. Web. 26 Feb 2024.

If this document didn’t answer your questions, please contact HGIC at or 1-888-656-9988.

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