Flavonoids are a group of plant chemical compounds found in green tea that have been associated with the prevention of a multitude of chronic conditions. Flavonoids are backed by numerous research studies as being antioxidant, anticancer, and anti-heart disease (1, 2, 3).
To be more specific, flavonoids act as scavengers of ROS (reactive oxygen species) which build up in our body as a result of stress – anything from sun exposure, alcohol intake, long work weeks, and poor eating habits. Elevations in ROS have been found in cases of cancer as they promote the proliferation of tumors and damage to DNA (4). Beyond cancer, multiple research studies have found that flavonoids are integral in preventing and reducing the risk of neurodegenerative diseases like Alzheimers and Parkinsons’ (5,6). Increased flavonoid intake was associated with an overall reduced risk of all-cause mortality in aging women according to a 2015 study in the American Journal of Clinical Nutrition (3). The common flavonoid in green tea called EGCG (a catechin) that has even been linked to increased body weight and fat loss (7).
Ok, ok so we know that these compounds are good for us, but does that mean we should be drinking cup after cup of green tea?
A cup of regular green tea has the highest content of flavonoids with black tea following and then oolong according to the USDA Database for Flavonoid Content of Selected Foods (8). Interestingly enough, the decaffeinated varieties all have much lower concentrations of flavonoids, so I recommend drinking regular caffeinated tea if possible. For the most benefit, research generally suggests anywhere from 3-5 cups of green tea daily (5,6). If you’re very caffeine sensitive, keep in mind that 3 cups is the rough equivalent of 1 cup of coffee.
BUT – tea is not the flavonoid savior – you can find all kinds of flavonoids in other plants – specifically herbs! Herbs like dried parsley or oregano actually have exceedingly higher amounts of flavonoids than green tea (9). Therefore, make an effort to add more herbs to soups and stews when cooking or try marinating meats or fish in spice/herb blends. To reduce overall chronic disease risk, prioritize the daily consumption of more high flavonoid foods and drinks – my favorite sneaky sources include 85% dark chocolate, chickpeas, and capers.
Can you go overboard? While there is not much study support regarding the toxic effects of overconsumption of flavonoids or green tea, keep in mind (as is the case with many things) that there can be too much of a good thing. Too much tea can increase your intake of tannins – a compound that can inhibit your body’s absorption of minerals like iron. In addition, if tea isn’t well sourced it has a risk of being contaminated with pesticides or heavy metals. Always look for organic varieties of tea and ideally you should source from companies that 3rd party test for heavy metals. This green tea from Japan does just that and has a wonderful taste (I love the organic sencha!). More of a latte person? Try using organic matcha powder in our bulletproof matcha latte recipe here.
The bottom line – choose organic green tea and keep intake to 3-5 cups daily for maximum benefits. Consume a variety of colorfully pigmented fruits and vegetables for an additional increase in flavonoid intake!