A large number of phytonutrients fall into the flavonoid category. They are found in a variety of plant foods.
The types of flavonoids include:
Catechins. Green tea is an especially good source of catechins. The drink may help prevent certain types of cancer.
Hesperidin. Found in citrus fruits, this flavonoid works as an antioxidant reducing inflammation in the body to help prevent chronic disease.
Flavonols. Quercetin is a well-studied type of flavonol. It is found in:
It might help reduce people's risk of asthma, certain types of cancer, and coronary heart disease.
Resveratrol is found in:
- Purple grape juice
- Red wine
It acts as an antioxidant and anti-inflammatory.
Some research suggests that resveratrol might play a role in reducing the risk of heart disease and certain cancers. And it may help extend life, animal studies have shown. But more human studies are needed to establish a clear relationship.
Glucosinolates are found in cruciferous vegetables, including:
- Brussels sprouts
They give these vegetables their sharp odor and flavor. The glucosinolates turn into other chemicals during the cooking process and while you digest these foods. These chemicals may help hold in check the development and growth of cancer.
Because of their structure, phytoestrogens can exert estrogen-like effects. They can also block the effects of your natural supply of estrogen.
Soy foods contain isoflavones -- a type of phytoestrogen. Some evidence suggests that soy foods may be linked to:
- Lower risk of endometrial cancer
- Lower risk of bone loss in women
Your body converts lignans, another type of phytonutrient, into chemicals with some estrogen-like effects. Two especially good sources of lignans are:
However, research supporting a role for lignans in preventing endometrial cancer or osteoporosis is limited.