Flavonols
Synopsis
Flavonols are a subclass of flavonoids, a large group of polyphenolic compounds found abundantly in fruits, vegetables, herbs, and plant-derived beverages. They are known for their antioxidant, anti-inflammatory, and cardioprotective properties. Common dietary flavonols include quercetin, kaempferol, myricetin, and isorhamnetin, found in foods such as onions, apples, kale, broccoli, berries, grapes, tea, and red wine.
Flavonols act as free radical scavengers and can help stabilize reactive oxygen species (ROS), reducing oxidative stress at the cellular level. They also modulate enzymes involved in inflammation (like COX-2), influence signaling pathways (including NF-κB and MAPK), and support the integrity of the vascular endothelium. As such, they are studied for their potential to lower blood pressure, reduce LDL oxidation, improve endothelial function, and support brain health.
Some flavonols, particularly quercetin, are used in supplement form for immune support, allergy relief, and respiratory health, thanks to their antihistamine-like effects. Others are explored for their impact on metabolic syndrome, diabetes, and cognitive aging. Their bioavailability can vary widely, so they are often paired with absorption enhancers like bromelain or vitamin C in supplements.
Historical Use
Although the term “flavonol” and the isolation of specific compounds are modern developments, plants rich in flavonols have a long history of use in traditional medicine systems around the world. For example, onions and elderberries, both high in quercetin, were used in European herbalism for treating colds, inflammation, and cardiovascular issues. Ginkgo biloba, which contains the flavonols kaempferol and quercetin, has been used for centuries in Traditional Chinese Medicine (TCM) for cognitive function and circulation.
In Ayurveda, many flavonol-rich herbs like Moringa, Tulsi (holy basil), and Indian gooseberry (amla) were utilized for their rejuvenating, immune-boosting, and detoxifying effects. Although ancient practitioners did not know these compounds by name, they observed the systemic benefits of such plants and applied them accordingly.
The scientific understanding of flavonols began advancing in the 20th century, particularly with the rise of nutrition science and epidemiology, where researchers noticed correlations between diets rich in colorful fruits and vegetables and lower rates of chronic disease. This led to the classification of flavonoids and further subtyping into groups like flavonols.
Today, flavonols are at the center of nutrigenomics and functional food research, valued not only as dietary antioxidants but as biologically active agents that influence cellular health and aging processes. They serve as a prime example of how modern science continues to validate and refine the health-promoting aspects of traditional plant-based diets.
Body Systems
Arteries (Traditional)
Circulatory System (Science)
Immune System (Science)
Mitochondria (Science)