Flavonoids are phytonutrients (plant compounds) that can be found in nearly all fruits, vegetables, grains, flowers, and herbs. They have a variety of beneficial biochemical and antioxidant effects that are associated with various diseases such as cancer, Alzheimer’s disease, heart disease, and diabetes. Flavonoids are well-known for their health-promoting properties and are now considered an essential component in a wide range of nutraceutical, pharmacological, medical, and cosmetic applications. This is due to their antioxidant, anti-inflammatory, anti-mutagenic, and anti-carcinogenic properties, as well as their ability to modulate key cellular enzyme function.
Flavonoid-rich foods are known as superfoods because of their surprising health benefits. All plant-based foods, such as fruit, vegetables, whole grains, legumes, nuts, and wine, fall under this category. They are primarily found in tea, wine, leafy vegetables, onions, apples, berries, cherries, soybeans, and citrus fruits. Flavonoids are classified into three types: bioflavonoids, isoflavonoids, and neoflavonoids.
The discovery of a low cardiovascular mortality rate as well as the prevention of coronary heart disease (CHD) fueled further research into flavonoids. However, neither the FDA nor the European Food Safety Authority (EFSA) has approved any health claims for flavonoids, nor have any flavonoids been approved as prescription drugs. The US Food and Drug Administration has issued numerous warnings to dietary supplement companies regarding illegal advertising and false health claims.
Since studies have suggested that flavonoids have chemopreventive effects on carcinogenesis, the anticancer activity of dietary flavonoids has become an important topic. Nonetheless, several epidemiologic studies examining the relationship between dietary flavonoid intake and the risk of cancer have produced inconclusive results and identified conflicting evidence. One possibility could be that different flavonoid subclasses in the diet have varied characteristics and effects on the body. As a result, it’s crucial to figure out how each flavonoid subclass contributes to the chemopreventive action of these dietary compounds.
Cancer Prevention
Numerous research has already been published on the role of flavonoids in cancer prevention and treatment. Several flavonoids have been shown to have antimutagenic properties. Polyphenol-rich diets appear to be connected to a lower risk of prostate cancer. The administration of soybean isoflavones seem to have a positive effect on prostate-specific antigen levels, based on the results of various clinical studies. Furthermore, a recent study in European men discovered that higher levels of circulating genistein are associated with a lower risk of prostate cancer.
Epidemiological studies have long identified that Breast cancer incidence is lower in most Asian countries than in Western countries, and women of Asian origin eating a Western diet have the same breast cancer incidence as Western women. According to a study published in the British Journal of Cancer in 2003, women who consumed more flavones had a decreased risk of developing breast cancer.
Cardiovascular Disease
In multiple studies, a flavonoid-rich diet has been linked to a considerable reduction in cardiovascular morbidity and mortality. Flavonoid and isoflavone consumption was discovered to be the primary phytochemicals contributing to Japanese women’s low incidence of coronary heart disease. The findings suggest that Japanese women’s high consumption of flavonoids and isoflavones may contribute to their low incidence of coronary heart disease when compared to women in other countries.
Diabetes
Flavonoids reduce the pathogenesis of diabetes and its complications by regulating glucose metabolism, hepatic enzyme activity, and lipid profile. Various physiological studies have concluded that free radicals may contribute to the autoimmune destruction of pancreatic cells, resulting in diabetes and that they may impair insulin action. A higher intake of fruit and vegetables, especially berries, green leafy vegetables, yellow vegetables, and cruciferous vegetables have a high ability to scavenge free radicals, lowering the risk of type I and type II diabetes mellitus.
Neurodegenerative Disease
The anti-inflammatory and antioxidant properties of flavonoids may aid in the prevention of neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Flavonoid levels have been linked to a lower risk of these diseases in animal studies. According to a study published in the European Journal of Epidemiology, people who consumed the most flavonoids had a 50% lower risk of developing dementia than those who took the least.