Detox Learning Center

Phytochemicals 101: Types, Sources, and Benefits

What Are Phytochemicals?

Want to provide your body with natural, health-boosting nutrients? Fill up on phytochemicals.

Phytochemicals are powerful nutrient-like substances found in plants, also called phytonutrients. Unlike major nutrients like vitamin C, you do not develop a serious deficiency without phytonutrients. Yet these compounds can be invaluable to your health.

Eating a diet high in phytochemicals is strongly connected with better health. They could improve your ability to detox, as well as boost your immune system. Phytochemicals may also help protect against age-related diseases, such as diabetes, heart disease, and osteoporosis. (1, 2

So growing up, when your mom encouraged you to eat your fruits and veggies, she knew what she was talking about. 

Here’s a closer look at why we need phytochemicals, where to find them, and the different types.

How Do Phytochemicals Benefit You?

Scientists have already identified over 5,000 different types of phytochemicals. But they admit there are many more to discover, as well as more to learn about their potential benefits. (3)

Here's some of those many benefits already researched. Filling up on phytonutrients may help to: 

  • Boost the immune system (4)
  • Combat oxidative stress and free radicals (5)
  • Decrease blood sugar levels (56)
  • Lower blood pressure (4
  • Lower cancer and diabetes risk (57)
  • Prevent chronic disease (48)
  • Protect from pathogens (91011)
  • Protect your brain and liver (4)
  • Reduce cholesterol (4)
  • Reduce inflammation (51213)
  • Support detoxification (514)
  • Ward off osteoporosis (4)

Benefits of phytochemicals

What Foods Are Rich in Phytochemicals?

The good news is getting plenty of phytochemicals is fairly easy, as well as tasty.

Fresh, whole foods are the best sources of phytochemicals. All plant-based foods contain phytonutrients, including fruits, vegetables, nuts, and herbs. But keep in mind processing methods may lower the phytonutrient content of some foods. (15

The bright colors of fruits and vegetables — such as green, purple, red, or yellow — may help indicate what type of phytochemicals they contain. Why? Because a plant’s phytochemicals help determine its color, scent, and flavor. For example, the beautiful red, purple, and blue hues from berries are anthocyanins. (3, 1617)   

But foods without bright colors can have phytochemicals as well. Potatoes and cauliflower, for example, are still good sources of phytochemicals. Nuts like almonds, cashews, and hazelnuts contain several phytonutrients. And both tea and dark chocolate are not brightly colored, yet they are packed with health-boosting phytonutrients. (3, 181920)

Essential oils can be a potent source of these plant compounds as well. Pine needles, cedar, and lavender are a few examples of essential oils used for health, which come from their phytochemical content. Even the smell of some essential oils lowers inflammation. (21, 22, 23)    

What Are the Main Types of Phytochemicals?

With thousands of phytochemicals, you may wonder which are most common and what potential health payoffs they have. Here’s five major phytochemicals — anthocyanins, tannins, lutein and zeaxanthin, sulforaphane, and eugenol — and what they offer the body.

Benefits of Anthocyanins

The word anthocyanin comes from the Greek words for ‘flower’ and ‘blue.’ This phytochemical gives fruits and vegetables their vivid red, blue, and purple tints. Scientists have discovered over 700 different types of anthocyanins. (24, 25, 26)

Anthocyanins have been widely studied in labs, animals, and humans. Studies suggest they: 

  • Decrease cancer risk (27)
  • Eliminate free radicals (2528)
  • Help control weight (27)
  • Help prevent heart disease (27, 29)
  • Increase insulin sensitivity (30, 31)
  • Lower inflammation (27)
  • Protect DNA (26)
  • Protect the brain (31)
  • Reduce diabetic complications (27)

Anthocyanins also potentiate other phytochemicals, meaning they help boost the benefits found in other phytonutrients. (32)

What Foods Have Anthocyanins?

Knowing that anthocyanins are associated with red, blue, and purple makes it easier to remember its sources. Berries, cherries, currants, grapes, and plums are rich sources. But don’t forget vegetables like purple potatoes or red cabbage. (17

Cherries are a source of anthocyanins

Benefits of Tannins

Tannins are responsible for creating an astringent flavor — that mouth puckering, drying taste when you drink tea for example. (33) 

These bitter-tasting phytochemicals may have a variety of health benefits, such as:

  • Acting as an antioxidant (34)
  • Lowering blood pressure (35)
  • Lowering inflammation (34)
  • Fighting parasites, microbes, and viruses (34)
  • Reducing cancer risk (35)
  • Regulating your immune system (35)

Some people think that tannins interfere with iron absorption in food. But research has found that your body adapts over time and isn’t affected. (33)

What Foods Have Tannins?

You can fill up on these phytonutrients in many different foods. Tart fruits like cranberries, currants, and blackberries are good sources. But sweeter fruits like apples, grapes, peaches, and strawberries have them as well. (34)

Nuts — such as almonds, hazelnuts, pecans, pistachios, and walnuts — contain tannins. Barley, beans, lentils, and rice are also tannins sources. Along with this, tea is a common way people consume tannins. (34)

Cacao beans and dark chocolate are high sources of tannins, so indulging in a little dark chocolate can help you get your share of this phytonutrient. (34)

Lastly, antiparasitic herbs like vidanga contain tannins, which is where they get some of their medicinal properties. (36)

Nuts are a high source of tannins

Benefits of Lutein and Zeaxanthin

Lutein and zeaxanthin can give foods a rich orange or yellow color. These phytochemicals are potent antioxidants, most commonly known for their role in eye health. Your retina holds the highest concentration of lutein and zeaxanthin in your body. (37)

These phytochemicals absorb 40-90% of blue light, helping protect your retina from damage. Their strong antioxidant capacity may also reduce oxidative stress, especially important in the retina — it has the highest amount of oxidative stress in the body. (37)

These phytochemicals could also increase eye function, allowing you to see with more clarity and be bothered less by glaring lights. (38)

Along with these optical benefits, lutein and zeaxanthin may also: 

  • Enhance memory and brain function (38, 39)
  • Enhance the body’s use of insulin (40)
  • Improve skin health (41)
  • Lower blood pressure (40)
  • Reduce inflammation (40)
  • Support heart health (40)

    What Foods Have Lutein and Zeaxanthin?

    As already mentioned, these phytonutrients are associated with the colors orange and yellow. Egg yolks, orange peppers, oranges, pumpkins, and yellow corn contain lutein and zeaxanthin. (42)

    But if you want a whopping dose of these phytonutrients, go for green. Kale, parsley, romaine lettuce, and spinach are excellent sources of lutein and zeaxanthin. Pistachios are surprisingly high in these phytonutrients as well. (42)

    Having some other dietary fat with these foods supports your absorption of lutein and zeaxanthin. For example, don’t skip the olive oil dressing on your romaine lettuce salad if you need more of these powerful phytonutrients. (42)

    Yellow corn is a source of lutein and zeaxanthin

    Benefits of Sulforaphane 

    Sulforaphane is a potent antioxidant and highly researched for its potential anticancer activity.

    Animal and human cell studies suggest that sulforaphane helps lower inflammation, often associated with cancer development. Additionally, this phytochemical may prevent cancer from metastasizing, or spreading throughout the body. It could potentially trigger cancer cells to die as well. (43, 4445, 4647)

    Alongside anticancer properties, sulforaphane may provide benefits such as:

    • Boosting your ability to fight viruses (48)
    • Increasing detoxification (49, 50)
    • Increasing liver function (51)
    • Inhibiting bacterial and fungal pathogens (52)
    • Lowering autism symptoms (53)
    • Protecting your eyes (54)
    • Reducing depression and anxiety (55, 56)

    What Foods Have Sulforaphane?

    If you want to fill up on this powerful phytochemical, think green and include lots of cruciferous vegetables in your diet. Broccoli, cabbage, kale, and kohlrabi are great sources. The highest source, however, is 3-day-old broccoli sprouts. (57)

    If you want to ensure you absorb sulforaphane, spice it up with mustard. Mustard helps activate this phytochemical. (58)

    Broccoli sprouts are a high source of sulforaphane

    Benefits of Eugenol 

    Eugenol may act as a strong anti-inflammatory and antioxidant in your body. Plus, this powerful phytochemical could help eliminate parasites. (59, 60, 61, 62)

    Animal, test-tube, and human cell studies suggest other eugenol benefits may include:

    • Fighting fungus (63)
    • Inhibiting cancer (64)
    • Protecting the brain (65, 66)
    • Protecting the liver (67)
    • Reducing biofilm and bacteria (68)
    • Supporting heart health (69)
    • Supporting stomach health (70)

    What Foods Have Eugenol?

    You can find this potent phytochemical in basil, cinnamon, clove, cumin, fennel, nutmeg, and thyme. Clove is the highest source — its essential oil is an astonishing 45-90% eugenol. (64, 71)

    Coffee, mung beans, and soybeans have small amounts of this phytochemical. Fruits like bananas, melons, strawberries, and tomatoes contain some eugenol as well. (64, 72, 73)

    Clove is the highest eugenol source

    Eat the Rainbow

    To reap the vast benefits of phytonutrients, including the five above, try eating whole foods in a variety of different colors. Since phytochemicals can help determine food colors, similarly colored foods often share phytonutrients and benefits. If you eat the rainbow — or eat foods from all the different color groups — you can consume lots of different phytochemicals.

    Here's the general breakdown of the different color groups: (34, 74, 75)

    Colors of foods to eat for phytochemicals

    "Green" Foods 

    Examples of "green" foods include: artichokes, asparagus, avocados, broccoli, broccoli sprouts, celery, cucumbers, green beans, green peppers, kale, kiwi, spinach, and zucchini

    "Green" foods may contain these phytochemicals: EGCG, glucosinolates, indoles, isoflavones, isothiocyanates, lutein and zeaxanthin, and sulforaphane

    "Green" foods may help:

    • Promote wound healing and healthy gums
    • Support arteries, blood cells, eyes, liver, and lungs

    "Purple" Foods

    Examples of "purple" foods include: black beans, blackberries, blueberries, eggplants, elderberries, plums, purple cabbage, purple grapes, and raisins  

    "Purple" foods may contain these phytochemicals: anthocyanins, flavonoids, phenols, tannins, and resveratrol

    "Purple" foods may help:

    • Protect against cancer
    • Support arteries, bones, brain, cognition, healthy aging, and heart

    "Red" Foods

    Examples of "red" foods include: beets, cherries, cranberries, kidney beans, red beans, strawberries, tomatoes, and watermelon 

    "Red" foods may contain these phytochemicals: anthocyanins, ellagic acid, eugenol, hesperidin, lycopene, tannins, and quercetin

    "Red" foods may help:

    • Protect against cancer and heart disease
    • Support prostate, urinary tract, and DNA health


    "Yellow" Foods

    Examples of "yellow" foods include: apricots, cantoloupe, carrots, grapefruit, yellow beets, yellow pears, yellow peppers, and yellow winter squash  

    "Yellow" foods may contain these phytochemicals: alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein and zeaxanthin, and hesperidin

    "Yellow" foods may help:

    • Boost the immune system
    • Support heart and vision health

    "White" Foods  

    Examples of "white" foods include: apples, cauliflower, garlic, great northern beans, mushrooms, and onions

    "White" foods may contain these phytochemicals: allicin, ECGC, glucosinolates, indoles, tannins, and quercetin

    "White" foods may help:

    • Protect against cancer and heart disease
    • Support arteries, bones, and circulation

    Thrive with Phytochemicals

    A diet rich in phytonutrients can support the human body’s ability to thrive. Phytochemicals possess strong antioxidant activity, could help lower inflammation, and promote detoxification. They may also help protect you from pathogens, such as bacteria, viruses, and parasites. 

    All in all, diving into colorful fruit and veggies platters may have huge wellness payoffs. 

    Which fruits, vegetables, and herbs are you going to add to your next shopping list?      

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