What Are Phytonutrients?
Who would’ve thought that the same things that give plants their vivid colors could also help benefit our health? Spoiler alert: we did. Phytonutrients are what give fruits and vegetables their bright hues and provide yet another reason we should eat plant foods.
Phytonutrients—also called phytochemicals—are defined as bioactive plant-derived compounds linked to positive health effects.1 Interestingly enough, the first part of the word “phytonutrients,” phyto-, means plant.2
J.S. Bland, PhD, FACN, CNS, and functional medicine pioneer, says that “all families of plant food are known to contain phytonutrients, that is, unique substances produced during the natural course of plant growth and development that are specific to each plants’ genes and environment.”3
Phytonutrients play various roles within a plant. Not only do they give plant foods their colorful pigments, but they also protect plants. And by consuming them, we receive the benefits of phytonutrients, too.
Researchers have discovered that although they are not essential nutrients, phytonutrients have “important properties such as antioxidant activity, antimicrobial effects, modulation of detoxification enzymes, stimulation of the immune system, decrease of platelet aggregation and modulation of hormone metabolism, and [other properties].”4
That’s quite a bit to digest, so let’s look at the fascinating world of phytochemistry in more depth.
Types
Some common phytonutrient families include saponins, stilbenes, lignins, isoflavones, flavonols, limonoids, organo (allylic sulfides), carotenoids, phytosterols, anthocyanins, and catechins. Within these groups are many more types. In fact, there are hundreds of thousands of phytonutrients found within plant foods!
Isoflavonoids are a type of phytonutrient found in legumes and whole soybean products; they are antioxidants, anti-inflammatory, and more.5 And this is just isoflavonoids; other phytonutrients offer additional benefits.
Take carotenoids, for instance. They are contained in plant foods with red, yellow, and orange pigments like carrots, tomatoes, and sweet potatoes. They contribute to cardiovascular protection and have antioxidant and anti-inflammatory properties.6
Anthocyanins are found in plant foods with blue, red, and violet pigments such as blueberries, raspberries, and cherries. They defend cells, prevent blood clotting, and could lower blood pressure. Berries and red wine contain anthocyanins.
What do blueberries, onions, parsley, tea, apples, citrus, and coffee have in common? They all contain flavonoids, which act as chemical messengers, physiological regulators, and cell cycle inhibitors. Flavonoids may fight inflammation, according to Harvard Health Publishing.7
You can consume limonoids by eating citrus fruits. Limonoids can act as antioxidants.
Phytosterols are plant-like sterols like vegetable oil, wheat germ, whole grains, and bran. They compete with cholesterol absorption.
As you can see, phytonutrients can benefit our health in many ways and can be received by eating various plant foods like fruits, vegetables, nuts, seeds, grains, and legumes. Here are some foods rich in phytonutrients:8
- Berries
- Broccoli
- Brussels sprouts
- Cabbage
- Cantaloupe
- Carrots
- Cauliflower
- Chickpeas
- Garlic
- Mangoes
- Onion
- Oranges
- Peppers
- Tomatoes
- And more!
Starting to see a pattern? Maybe we’ll follow this up with a much, much shorter piece about what phytochemicals can’t do.
Functions
We briefly touched on some of the roles phytonutrients or phytochemicals play, but let’s dig a little deeper.
As mentioned, many phytochemicals have antioxidant properties. “Antioxidants are substances that prevent damage to cells from highly reactive, unstable molecules called ‘free radicals,’” says Karen Collins, MS, RDN, CDN, FAND, and nutrition advisor at the American Institute for Cancer Research. Free radicals can be very damaging to our health if kept unchecked. They can lead to cell damage.9 Phytonutrients provide support for that much needed checking.
Phytonutrients play a role in metabolism, as well. According to Gary Beecher, a research chemist at the Beltsville Human Nutrition Research Center in Maryland, phytochemicals elicit biological responses. For example, glucosinolates, isothiocyanates, indoles, and phytoestrogens alter estrogen metabolism.10
In addition, phytonutrients are involved in your skin’s health. The skin is the largest organ of the body and the most exposed to the environment. Phytonutrients can protect skin against damage from sunlight exposure, inflammation, oxidative stress, the breakdown of cells, and more. In particular, foods that contain vitamin E, flavonoids, carotenoids, beta-carotene, lycopene, and lutein are most beneficial.11
According to Nutrients journal, vitamin E may act as a protectant with the aid of other antioxidants. One phytonutrient family—flavonoids—can too. Flavonoids have been “radical scavengers, UVA absorbent, cytoprotective, anti-inflammatory, anti-apoptotic, and inhibit DNA damage, and affect cellular signaling pathways.”12 Now what does all that scientific jargon mean? Basically, flavonoids help a lot of areas of the body!
Lycopene is another phytonutrient that is involved in skin health. It is part of the carotenoid family and is found in tomatoes and other red produce. Nutrients explains that there is significant correlation with skin roughness and lycopene concentrations in the skin. Lycopene can be used to increase antioxidant activity in skin.
Lutein contributes to skin color. It is found in leafy green vegetables, broccoli, corn, peas, kale, spinach, romaine lettuce, bell peppers, and parsely.13 14
Some phytonutrients, like lutein, affect eye health. Nutrients shares that lutein acts as an antioxidant and absorbs blue light, which is emitted from electronic devices and sunlight.
“Bluelight is of concern because it has more energy per photon of light than other colors in the visible spectrum,” says Dr. David Ramsey, contributing writer at Harvard Health Publishing. “Blue light, at high enough doses, is therefore more likely to cause damage when absorbed by various cells in our body.”15
Intense blue light can affect eye health; electronic devices emit a less intense kind. Their blue light is actually more likely to affect your sleep, circadian rhythm, and other aspects of your health before harming your eyes. Still, reducing any amount of a bad thing can be a good idea, so be sure to snack on some broccoli to increase your intake of lutein and receive its benefits.
Phytonutrients also play a role in detoxification. Several compounds found in plant foods (phytochemicals) have been found to help support detoxification of harmful substances. The liver operates to rid the body of toxins, and nutrients provide help in carrying out this task. Inability to detoxify the body can lead to a number of health issues. 16
Glutathione is one of these compounds. Free radicals can cause cell damage and mutation. To increase your intake of glutathione, eat avocado, asparagus, broccoli, grapefruit, potatoes, strawberries, oranges, tomatoes, peaches, and spinach.17
Adequate nutrition may help maintain proper bodily function and can allow you to enjoy better health as a result.
Bone health is also influenced by phytonutrients. An article in the British Journal of Clinical Pharmacology explains how a high consumption of fruits and vegetables positively affects bone health, particularly in how they might protect against the deterioration of bone tissue during aging.18
The article states that “dietary patterns consisting of a high consumption of fruits and vegetables, legumes, seafood, nuts, seeds, rice, and/or rice dishes have been shown to be directly associated with bone mineral density.” As you now know, many of these foods contain phytonutrients. Lycopene is one of these phytonutrients.
Data shows a link between lycopene intake and bone mass, bone turnover, and fracture risk. Higher levels of lycopene were proven to positively affect bone mineral density in the lumbar vertebrae and to lower the risk of hip and nonvertebral fractures in older men and women.19 Lycopene can be found in tomatoes, watermelon, pink grapefruit, pink guava, papaya, dried apricot, and rosehips.20
Another compound involved in bone health are polyphenols. Polyphenols are found in fruits, vegetables, beans, grains, and more. Types of polyphenols include phenolic acids, flavonoids, stilbenes, tannins, coumarins, and lignans. Flavonoids are the type most associated in supplementing bone health. Within that subgroup, flavonols are believed to reduce risk of fracture and increase bone mineral density; however, more research is needed.21
Phytochemicals sure do a lot!
The Last Bite
Phytonutrition is becoming more widely studied and understood, and there’s real science to support the research. We’ve always known that eating fruits and vegetables is good for us. Turns out your mom knew what she was talking about when she told you to “eat your veggies.”
The role of nutrition in our overall health is great—greater than you may have ever thought! We have just scratched the surface when it comes to knowing and understanding the effect of phytonutrients on health. By adopting more plant foods into your daily diet, you could set yourself up for a healthier, and ultimately more satisfying, life.
If there’s one thing you take away from this, let it be to eat a diet full of colorful plants!
Check out Dr. Howard’s* video on the color of fruits and vegetables! Dr. Howard is the founder and formulator of Balance of Nature.
*Chiropractic Physician (Retired). Professor of Medical Science and Research, Pavlov Medical University. Dean of Foreign Student Affairs, St. Petersburg Pediatric Medical University (Retired)
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[1] “Phytonutrient.” Accessed June 15, 2020. https://www.merriam-webster.com/dictionary/phytonutrient. Merriam-Webster.
[2] “Phyto-,” Merriam-Webster (Merriam-Webster), accessed July 6, 2020, https://www.merriam-webster.com/dictionary/phyto-.
[3] Bland, J S. “Phytonutrition, Phytotherapy, and Phytopharmacology.” Alternative therapies in health and medicine. U.S. National Library of Medicine, November 1996. https://pubmed.ncbi.nlm.nih.gov/8942046/.
[4] Ditu, Lia-Mara, Madalina E. Grigore, Petronela Camen-Comanescu, and Alina Maria Holban. “Introduction in Nutraceutical and Medicinal Foods.” Therapeutic, Probiotic, and Unconventional Foods. Academic Press, April 20, 2018. https://www.sciencedirect.com/science/article/pii/B9780128146255000017.
[5] Marcus, Jacqueline B. “Nutritional and Physical Concerns in Aging.” Aging, Nutrition and Taste. Academic Press, April 12, 2019. https://www.sciencedirect.com/science/article/pii/B9780128135273000028.
[6] “Fill up on phytochemicals.” Harvard Health Publishing. February 2019. https://www.health.harvard.edu/staying-healthy/fill-up-on-phytochemicals.
[7] Ibid.
[8] “Foods Containing Phytochemicals.” Breastcancer.org. https://www.breastcancer.org/tips/nutrition/reduce_risk/foods/phytochem. Published February 5, 2015.
[9] Collins, Karen. “Antioxidants and Phytochemicals.” HealthTalk: What's the difference between an antioxidant and a phytochemical. American Institute for Cancer Research, March 4, 2020. https://www.aicr.org/resources/blog/healthtalk-whats-the-difference-between-an-antioxidant-and-a-phytochemical/.
[10] Beecher, Gary R. “Phytonutrients' Role in Metabolism: Effects on Resistance to Degenerative Processes.” Nutrition Reviews. Oxford University Press, September 1, 1999. https://academic.oup.com/nutritionreviews/article/57/9/3/1860707.
[11] Evans, Julie A., and Elizabeth J. Johnson. “The Role of Phytonutrients in Skin Health.” MDPI. Molecular Diversity Preservation International, August 24, 2010. https://www.mdpi.com/2072-6643/2/8/903/htm.
[12] Ibid.
[13] Ibid.
[14] WebMD Editorial Contributors. “Foods High in Lutein.” WebMD. WebMD, October 22, 2020. https://www.webmd.com/diet/foods-high-in-lutein.
[15] Ramsey, David. “Will Blue Light from Electronic Devices Increase My Risk of Macular Degeneration and Blindness?” Harvard Health Blog. Harvard Health Publishing, May 1, 2019. https://www.health.harvard.edu/blog/will-blue-light-from-electronic-devices-increase-my-risk-of-macular-degeneration-and-blindness-2019040816365.
[17] Phytochemicals. phytochemicals.info. Accessed June 11, 2020. https://www.phytochemicals.info/phytochemicals/glutathione.php.
[18] Sacco, Sandra Maria, Marie‐Noëlle Horcajada, and Elizabeth Offord. “Phytonutrients for Bone Health during Ageing.” British Pharmacological Society | Journals. John Wiley & Sons, Ltd, February 5, 2013. https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1111/bcp.12033.
[19] Ibid.
[20] Mourvaki , Evangelia, Stefania Gizzi, Ruggero Rossi, and Stefano Rufini. “Passionflower Fruit-a ‘New’ Source of Lycopene?” NIH National Library of Medicine. Journal of medicinal food, 2005. https://pubmed.ncbi.nlm.nih.gov/15857218/#:~:text=Besides%20tomatoes%20and%20tomato%20products,contain%20relatively%20large%20amounts%2C%20too.
[21] Sacco, Sandra Maria, Marie‐Noëlle Horcajada, and Elizabeth Offord. “Phytonutrients for Bone Health during Ageing.” British Pharmacological Society | Journals. John Wiley & Sons, Ltd, February 5, 2013. https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1111/bcp.12033.
