Antioxidant effect – The antioxidants present in the flavonoids help in protecting the body's cells and tissues from free-radicals and other environmental contaminants. The free-radical damage can increase the risk of heart diseases by increasing the LDL cholesterol levels in the body.

Anti-inflammatory effect – A type of flavonoids present in cocoa and chocolate can reduce dangerous inflammation in the arteries.

Heart disease risk – Flavonoids can help in reducing the blood pressure and cholesterol in the body which in turn reduces the risk of heart diseases.

Cancer risk – According to a study conducted by Linus Pauling Institute, Corvallis; flavonoids can inhibit many types of cancers. There are some evidences that prove high intake of flavonoids can decrease the risk of cancer in humans.

Some plant-based food groups that are rich in flavonoid content are:

Berries – The red, blue and purple berries are high in flavonoid content. The darker and riper berries have higher flavonoid value.

Tree fruits – Fruits that grow on trees like grapefruit, lemons, apples, mangoes, limes and oranges are rich in flavonoid content. The fruits like apples, pears, plums, peaches and apricots contain flavonoids of the group catechin and epicatechin, and are best to be consumed with the skin on.

Beverages: According to a study done by University of Western Australia (UWA) School of Medicine, and pharmacology, a type of flavonoid known as Quercetin, which is found abundantly in black tea, has shown promising effects in protecting blood vessels against oxidative damage and lowering cardiovascular disease (CVD) risk, reported Zee News.

Vegetables: Green and red vegetables, particularly, are rich in flavonoids. Green vegetables are rich in flavones - apigenin and luteolin, whereas onions are rich in quercetin.

Nuts and beans – They are not only rich in proteins but are also high in flavonoids.