Polyphenols are an enormous family of nutrients that are unique to plants. They play starring roles in the color and flavor of fruits, spices, seeds, coffee, plant oils (essential oils as well as cooking oils), cocoa, vegetables, beans, tea, and herbs, not to mention many alcoholic beverages.
What are polyphenols? Why do they matter?
Technically speaking, polyphenols are nutrients that specialize in protecting plants from stresses they encounter throughout their stages of growth, like weather challenges or overgrazing by animals or insects. They gift every single plant with distinctive health benefits that include survival advantages for the plants themselves as well as the potential to provide health protection for anyone and anything that eats them.
Here are a very few examples of polyphenols — many of which your body already knows and loves!
- Flavonoids like quercetin and catechin in citrus fruits, buckwheat, and green tea.
- Anthocyanins and stilbenes (resveratrol is a famous example) found in berries.
- Lignans such as those in sesame seeds, flaxseeds, and their oils.
- Curcumin from that inimitable curry spice turmeric.
- Tyrosols found in olives, olive leaves, and olive oil.
- Other rare compounds found in rosemary (carnosol and rosmanol, for instance) and Himalayan Tartary Buckwheat (like 2-hydroxybenzylamine, or 2-HOBA).
For your body, polyphenols are a sort of non-stop wellness package. Voluminous research has discovered myriad positive health effects associated with them.
- Strengthening blood vessels while also aiding their ability to relax when needed (think: blood pressure).
- Helping trigger immune cell renewal for better immune rejuvenation, improving immune balance between offense and defense, and curbing the development of allergies, inflammation, and other immune disturbances. For background on the importance of immune rejuvenation, click on this previous post about Immunity + Infection.
- Certain polyphenols, like quercetin, can act as prebiotics that feed the “friendly flora” in your intestines. For more on how prebiotics support immunity, click on this previous post about Immunity + Your Gut Microbiome.
- Some polyphenols are known to improve blood sugar dynamics to help minimize highs and lows that can harm your immunity and your body’s metabolism.
How to get polyphenols in your diet
The types and levels of polyphenols in plants vary with their stage of growth and part of the plant — for instance, whether it’s a seed or sprout or fruit, how ripe the fruits are, and whether the plant is putting out blossoms or stretching out its root system.
Cooking and processing also alter foods’ polyphenol contents. In addition, when we digest these foods in cooperation with the microbes living in our digestive tracts, they undergo further transformation. So how does one go about getting the best of what polyphenols have to offer?
- #1 is eating a wide variety of veggies, fruits, nuts, seeds, legumes, herbs, spices, plant beverages, and grains each day — and enjoying many of them fresh, in addition to those that are cooked. A great way to cover the spectrum is to indulge in foods from every color of the rainbow, from blackcurrants to green leafies to multi-colored bell peppers and beyond. And if they’re locally-grown, these plants will help train your immune system to respond well to the immune challenges you both face in your neck of the woods! For a big, bold list of Rainbow Foods, check out this previous posting on Immunity + Your Gut Microbiome.
- Home-brewed teas are an inexpensive, polyphenol-packed alternative to canned and bottled beverages. They present endless variety in potential combinations of fruit, herbal, spice, floral, and other flavors. How about black tea brewed with cinnamon, iced, with a few drops of edible rosewater added? Or limeade mixed with peppermint tea? Or cranberry juice blended with iced jasmine tea?
For a deeper dive
For a deeper dive into how food polyphenols can influence immune balance and long-term health, this 2018 article provides a good overview of recent scientific evidence.