For me, utilising polyphenols for your health is truly using food as medicine. This is where everyday foods like garlic, nuts, broccoli, flaxseeds, blueberries and green tea really shine. Let’s take a look at what polyphenols are and how to reap their health benefits.
What Are Polyphenols?
Polyphenols are also known as Phytochemicals (plant chemicals). Polyphenols are a class of compounds found in plants, nuts and seeds. The term polyphenol is often used to describe specific compounds that influence human health. They are not essential nutrients like vitamins and minerals, yet their benefits on various aspects of our health are quite remarkable.
There are more than 8000 polyphenol compounds identified in the scientific literature. Overall, epidemiologic studies reveal that dietary polyphenols are associated with lower chronic disease development.
Polyphenols are an abundant source of antioxidant compounds. Consuming polyphenols helps reduce the risk of inflammatory diseases, including cancer, diabetes and heart disease.
Common Polyphenols And Food Sources:
- Caffeine (coffee)
- Trigonelline (coffee)
- Alpha-carotene (carrots, pumpkin, orange)
- Beta-carotene (dark green leafy vegetables, pumpkin)
- Lutein (spinach, pawpaw, broccoli, rhubarb, plum)
- Zeaxanthin (spinach, kale, eggs)
- Lycopene (tomatoes, grapefruit, apricots)
- Apigenin - (parsley, celery, camomile)
- Luteolin - (broccoli, artichoke, camomile)
- Hesperetin, Naringenin (grapefruit)
- Cyanidins (blueberry, cherry, elderberry)
- Genistein, Daidzein (soy, legumes)
- Catechin, Epigallocatechins (green tea, cocoa)
- Quercetin (onion, kale, citrus)
- Kaempferol (spinach)
- Myricetin (tomatoes, nuts)
- Caffeic Acid (artichoke, apple, olive oil)
- Curcumin (turmeric)
- Indole-3-carbinol (Broccoli, kale, brussels sprouts)
- Phytoestrogens (flax, sesame, peptas, sunflower seeds)
- Alliin (garlic)
- Allicin (garlic)
- Sulforaphane (Broccoli sprouts, kale)
- Allyl isothiocyanate (mustard, wasabi)
- Sitosterol (almonds, cashews, peanuts, avocado)
- Campesterol (buckwheat)
- Resveratrol (peanuts, grapes)
- Proanthocyanidins (tea, blueberry, elderberry)
Image credit: Linus Pauling Institute
5 Polyphenols For Your Health
Epigallocatechin gallate (EGCG) is the major polyphenol found in green tea. EGCG has a wealth of research supporting its anti-cancer and cardiovascular properties. EGCG is the most widely studied chemical compound of the flavanol class of polyphenols. Other food sources of EGCG include cocoa, broad beans and prune juice. Pervin et al. (2019) established beneficial effects on cognitive function by green tea consumption. Another interesting quality of EGCG is the epigenetic effects it has on reducing cancer cell formation. Research shows EGCG has tumour-suppressing properties at a DNA level, making this polyphenol valuable in cancer prevention.
Health Benefits of EGCG
Curcumin is the active compound found in turmeric. Curcumin has been used therapeutically across ancient cultures for centuries. Modern research supports the medicinal properties of turmeric and the curcuminoids found within. Curcumin may also be a useful additive therapy in skin disorders.
A study published by Hanai et al. (2006) in Clinical Gastroenterology and Hepatology, found that curcumin improves ulcerative colitis symptoms. In this double-blind multicentre study, one study group received 2g of curcumin per day.. At the end of the study period, curcumin appeared to be a safe therapeutic intervention for maintaining remission in patients with inflammatory bowel disease.
Health Benefits of Curcumin
Quercetin is a polyphenol from the flavonoid class of phytochemicals. Quercetin is present in most plant foods and boasts therapeutic actions in the body. It is a potent antioxidant agent, which may protect against the development of cancer, diabetes and chronic diseases. Research suggests quercetin helps maintain healthy blood-glucose levels due to the effect on pancreatic function. Quercetin helps promote insulin secretion and improves glucose utilisation in body tissues.
Quercetin has the ability to target cancer cells, causing programmed cell death (apoptosis), according to Reyes-Farias et al. (2019). Quercetin also demonstrates positive cardiovascular effects as well. In a recent study, quercetin reduced peripheral vascular resistance and altered electrolyte levels in the kidney, thereby reducing blood pressure.
Health Benefits of Quercetin
- Regulates blood pressure
Notoriously associated with red wine consumption, resveratrol gained popularity as a cardioprotective polyphenol during the early 1990’s. During this time, a hypothesis known as the ‘French Paradox’ was explored. It was thought that moderate red wine consumption accounted for low incidences of heart disease in French populations, where high saturated fat foods were commonly consumed.
Don’t like red wine? Well, resveratrol is also naturally found in peanuts and berries. In fact, roasting peanuts appears to augment resveratrol’s biologic activity in the body. Good news for peanut fans!
Resveratrol also possesses anticancer and neuroprotective activities as shown in numerous studies. Resveratrol was found to reduce brain inflammation and aid the clearance of beta-amyloid plaques and subsequent Alzheimer’s disease in vivo studies.
Health Benefits of Resveratrol
- Improves Alzheimer’s symptoms
- Anti-aging properties
Sulforaphane is a personal favourite polyphenol. Sulforaphane studies have been illuminated by one of my molecular biology and research idols, Dr. Rhonda Patrick. Sulforaphane is an organosulfur compound and is found in broccoli, Brussels sprouts, cabbage and kale. Sulforaphane is highly concentrated and most bioavailable in broccoli sprouts. Sulforaphane modulates the expression of pro-inflammatory cell pathways and possesses anti-cancer properties. Sulforaphane ameliorates Alzheimer’s Disease symptoms according to research published in the International Journal of Molecular Sciences.
Health Benefits of Sulforaphane
- Relieves Alzheimer’s symptoms
- Liver detoxification
Capiralla, H., Vingtdeux, V., Zhao, H., Sankowski, R., Al-Abed, Y., Davies, P., & Marambaud, P. (2012). Resveratrol mitigates lipopolysaccharide- and Aβ-mediated microglial inflammation by inhibiting the TLR4/NF-κB/STAT signaling cascade. Journal of neurochemistry, 120(3), 461–472. https://doi.org/10.1111/j.1471-4159.2011.07594.x
Chaplin, A., Carpéné, C., & Mercader, J. (2018). Resveratrol, Metabolic Syndrome, and Gut Microbiota. Nutrients, 10(11), 1651. https://doi.org/10.3390/nu10111651
Cione, E., La Torre, C., Cannataro, R., Caroleo, M. C., Plastina, P., & Gallelli, L. (2019). Quercetin, Epigallocatechin Gallate, Curcumin, and Resveratrol: From Dietary Sources to Human MicroRNA Modulation. Molecules (Basel, Switzerland), 25(1), 63. https://doi.org/10.3390/molecules25010063
Eid, H. M., & Haddad, P. S. (2017). The Antidiabetic Potential of Quercetin: Underlying Mechanisms. Current medicinal chemistry, 24(4), 355–364. https://doi.org/10.2174/092986732366616090915370
Hanai, H., Iida, T., Takeuchi, K., Watanabe, F., Maruyama, Y., Andoh, A., Tsujikawa, T., Fujiyama, Y., Mitsuyama, K., Sata, M., Yamada, M., Iwaoka, Y., Kanke, K., Hiraishi, H., Hirayama, K., Arai, H., Yoshii, S., Uchijima, M., Nagata, T., & Koide, Y. (2006). Curcumin maintenance therapy for ulcerative colitis: randomized, multicenter, double-blind, placebo-controlled trial. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association, 4(12), 1502–1506. https://doi.org/10.1016/j.cgh.2006.08.008
Kumar, G., Tuli, H. S., Mittal, S., Shandilya, J. K., Tiwari, A., & Sandhu, S. S. (2015). Isothiocyanates: a class of bioactive metabolites with chemopreventive potential. Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine, 36(6), 4005–4016. https://doi.org/10.1007/s13277-015-3391-5
Malaguarnera L. (2019). Influence of Resveratrol on the Immune Response. Nutrients, 11(5), 946. https://doi.org/10.3390/nu11050946
Marambaud, P., Zhao, H., & Davies, P. (2005). Resveratrol promotes clearance of Alzheimer's disease amyloid-beta peptides. The Journal of biological chemistry, 280(45), 37377–37382. https://doi.org/10.1074/jbc.M508246200
Marunaka, Y., Marunaka, R., Sun, H., Yamamoto, T., Kanamura, N., Inui, T., & Taruno, A. (2017). Actions of Quercetin, a Polyphenol, on Blood Pressure. Molecules (Basel, Switzerland), 22(2), 209. https://doi.org/10.3390/molecules22020209
Oregon State University, Linus Pauling Institute, Resveratrol, https://lpi.oregonstate.edu/mic/dietary-factors/phytochemicals/resveratrol, viewed January 16 2022
Oregon State University, Linus Pauling Institute, Polyphenols, https://lpi.oregonstate.edu/mic/food-beverages/fruit-vegetables, viewed January 16 2022
Pace-Asciak, C. R., Hahn, S., Diamandis, E. P., Soleas, G., & Goldberg, D. M. (1995). The red wine phenolics trans-resveratrol and quercetin block human platelet aggregation and eicosanoid synthesis: implications for protection against coronary heart disease. Clinica chimica acta; international journal of clinical chemistry, 235(2), 207–219. https://doi.org/10.1016/0009-8981(95)06045-1
Pervin, M., Unno, K., Ohishi, T., Tanabe, H., Miyoshi, N., & Nakamura, Y. (2018). Beneficial Effects of Green Tea Catechins on Neurodegenerative Diseases. Molecules (Basel, Switzerland), 23(6), 1297. https://doi.org/10.3390/molecules23061297
Pervin, M., Unno, K., Takagaki, A., Isemura, M., & Nakamura, Y. (2019). Function of Green Tea Catechins in the Brain: Epigallocatechin Gallate and its Metabolites. International journal of molecular sciences, 20(15), 3630. https://doi.org/10.3390/ijms20153630
Reyes-Farias, M., & Carrasco-Pozo, C. (2019). The Anti-Cancer Effect of Quercetin: Molecular Implications in Cancer Metabolism. International journal of molecular sciences, 20(13), 3177. https://doi.org/10.3390/ijms20133177
Schepici, G., Bramanti, P., & Mazzon, E. (2020). Efficacy of Sulforaphane in Neurodegenerative Diseases. International journal of molecular sciences, 21(22), 8637. https://doi.org/10.3390/ijms21228637
Schneider, Y., Duranton, B., Gossé, F., Schleiffer, R., Seiler, N., & Raul, F. (2001). Resveratrol inhibits intestinal tumorigenesis and modulates host-defense-related gene expression in an animal model of human familial adenomatous polyposis. Nutrition and cancer, 39(1), 102–107. https://doi.org/10.1207/S15327914nc391_14
Takahashi, S., & Nakashima, Y. (2012). Repeated and long-term treatment with physiological concentrations of resveratrol promotes NO production in vascular endothelial cells. The British journal of nutrition, 107(6), 774–780. https://doi.org/10.1017/S0007114511003588
Vingtdeux, V., Giliberto, L., Zhao, H., Chandakkar, P., Wu, Q., Simon, J. E., Janle, E. M., Lobo, J., Ferruzzi, M. G., Davies, P., & Marambaud, P. (2010). AMP-activated protein kinase signaling activation by resveratrol modulates amyloid-beta peptide metabolism. The Journal of biological chemistry, 285(12), 9100–9113. https://doi.org/10.1074/jbc.M109.060061
Vollono, L., Falconi, M., Gaziano, R., Iacovelli, F., Dika, E., Terracciano, C., Bianchi, L., & Campione, E. (2019). Potential of Curcumin in Skin Disorders. Nutrients, 11(9), 2169. https://doi.org/10.3390/nu11092169
Wagner, A. E., Boesch-Saadatmandi, C., Dose, J., Schultheiss, G., & Rimbach, G. (2012). Anti-inflammatory potential of allyl-isothiocyanate--role of Nrf2, NF-(κ) B and microRNA-155. Journal of cellular and molecular medicine, 16(4), 836–843. https://doi.org/10.1111/j.1582-4934.2011.01367.x
Wikipedia Contributors. (2022, January 16). List of Phytochemicals. Retrieved from Wikipedia website: https://en.wikipedia.org/wiki/List_of_phytochemicals_in_food, viewed January 16 2022
Wikipedia Contributors. (2022, January 16). Health Effects of Polyphenols. Retrieved from Wikipedia website: https://en.wikipedia.org/wiki/Health_effects_of_phenols_and_polyphenols, viewed January 16 2022
Yang, L., Zhang, W., Chopra, S., Kaur, D., Wang, H., Li, M., Chen, P., & Zhang, W. (2020). The Epigenetic Modification of Epigallocatechin Gallate (EGCG) on Cancer. Current drug targets, 21(11), 1099–1104. https://doi.org/10.2174/1389450121666200504080112